Journal articles: 'Field gas sampling'

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Lawer, Janelle. "Gas sampling for mercury analysis." APPEA Journal 61, no. 2 (2021): 559. http://dx.doi.org/10.1071/aj21013.

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Historically, gas sampling for mercury has been neither accurate nor precise. In some instances, limited understanding of mercury in gas reservoirs has contributed to health, safety and environment (HSE) incidents and project cost escalation. Quality gas sampling for mercury is recognised as a critical element in project planning, best conducted in the exploration and appraisal phases of a field. Early knowledge of mercury concentrations can contribute to the success of development planning, HSE processes and production facility design. Gas Field X on the North West Shelf of Western Australia is in a region of variable mercury-in-gas concentrations. The recent Field X development drilling program commenced with a sampling plan optimised and focussed on mercury analysis using industry best practice operational, logistical and analysis techniques with the intent of building a statistically representative dataset of mercury concentrations. Procedures developed included investigating major sources of scavenging and contamination, innovative pre-job equipment preparation, use of multiple data sources (downhole and surface sampling, offshore and onshore analysis) and blind cross-checking between different laboratories and equipment types. All data has been through rigorous post-analysis quality control. The results of this unprecedented new dataset represent a case study of industry best-practice gas sampling delivering high confidence and repeatable data.

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Tollefson, Jeff. "Air sampling reveals high emissions from gas field." Nature 482, no. 7384 (February 2012): 139–40. http://dx.doi.org/10.1038/482139a.

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Wu, Sheng, Andrei Deev, Yan Zhuang, Le Lu, Zhengyou Wang, Yongchun Tang, and Andrew Sneddon. "Fast Sampling Field Deployable Mud Gas Carbon Isotope Analyzer." Geosciences 10, no. 9 (September 4, 2020): 350. http://dx.doi.org/10.3390/geosciences10090350.

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We report the details of a field deployable mud gas carbon isotope analyzer for mud gas analysis based on coupling a gas chromatograph with a mid-infrared spectrometer using a quantum cascade laser and hollow waveguide. The GC–IR2 (gas chromatograph–infrared isotope ratio) system features a fast sampling cycle as short as 123 s for analyzing all three components, i.e., methane, ethane and propane. The samples are automatically diluted so the system could carry out effective measurements while sample concentrations vary from 400 ppm to 100% purity. The accuracy is guaranteed through periodic reference calibration, and variations due to field temperature changes are minimized.

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Aubinet, Marc, Lilian Joly, Denis Loustau, Anne De Ligne, Henri Chopin, Julien Cousin, Nicolas Chauvin, Thomas Decarpenterie, and Patrick Gross. "Dimensioning IRGA gas sampling systems: laboratory and field experiments." Atmospheric Measurement Techniques 9, no. 3 (March 31, 2016): 1361–67. http://dx.doi.org/10.5194/amt-9-1361-2016.

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Abstract. Both laboratory and field experiments were carried out in order to define suitable configuration ranges for the gas sampling systems (GSSs) of infrared gas analyzers (IRGAs) used in eddy covariance measurements.In the laboratory, an original dynamic calibration bench was developed in order to test the frequency attenuation and pressure drop generated by filters. In the field, three IRGAs of the same type equipped with different filters or different rain caps were installed and run and the real frequency response of the complete setup was tested. The main results are as follows. – Filters may have a strong impact on the pressure drop in the GSS and this impact increases with flow rate. – Conversely, no impact of the tested filters on cut-off frequency was found, GSSs with and without filters presenting similar cut-off frequencies. – The main limiting factor of cut-off frequency in the field was found to be the rain cap design. In addition, the impact of this design on pressure drop was also found to be noteworthy.

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Aubinet, M., L. Joly, D. Loustau, A. De Ligne, H. Chopin, J. Cousin, N. Chauvin, T. Decarpenterie, and P. Gross. "Technical note: Dimensioning IRGA gas sampling system: laboratory and field experiments." Atmospheric Measurement Techniques Discussions 8, no. 10 (October 20, 2015): 10735–54. http://dx.doi.org/10.5194/amtd-8-10735-2015.

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Abstract. Both laboratory and field experiments were carried out in order to define suitable configuration ranges for the gas sampling systems (GSS) of infrared gas analyzers (IRGA) used in eddy covariance measurements. In the laboratory, an original dynamic calibration bench was developed in order to test the frequency attenuation and pressure drop generated by filters. In the field, IRGAs equipped with different filters or different rain cups were installed and run and the real frequency response of the complete set-up was tested. The main results are that: – Filters may have a strong impact on the pressure drop in the GSS and this impact increases with flow rate. – On the contrary, no impact of the tested filters on cut off frequency was found, GSS with and without filters presenting similar cut off frequencies. – The main limiting factor of cut off frequency in the field was found to be the rain cup design. In addition, the impact of this design on pressure drop was also found noteworthy.

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Raina, Renata, and Patricia Hall. "Field Evaluation of Solid Sorbents for Ambient Air Sampling of Pesticides." Air, Soil and Water Research 3 (January 2010): ASWR.S5924. http://dx.doi.org/10.4137/aswr.s5924.

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Seven solid sorbents including Amberlite® XAD-2 and XAD-4, Tenax-TA®, Anasorb-747, Chromosorb 102, 108, and 750 were evaluated for the collection of the gas phase fraction of pesticides under field conditions at an agricultural site, Bratt's Lake, SK, located in the Canadian prairies. The polyurethane foam (PUF)/sorbent cartridge consists of two PUF layers which sandwich the solid sorbent and each layer was analyzed separately to determine which portion of the PUF/solid sorbent retained the pesticides and the extent of breakthrough. The pesticides that had high detection frequency throughout the study and ambient air concentrations well above MDL were triallate, trifluralin, ethalfluralin, and chlorpyrifos. All sorbents had improved collection efficiency as compared to a standard 7.6 cm PUF and the improvement varied with each pesticide. The most effective sorbents for trapping gas phase fraction of pesticides were XAD-2, XAD-4, Tenax-TA, and Chromosorb 108. The only sorbent not recommended for use is Chromosorb 750. For selected sampling periods when ambient concentrations were above detection limits a number of other organochlorine and organophosphorus pesticides also showed more efficient collection with PUF/solid sorbent cartridges as compared to PUF cartridge. Shorter sample collection periods of 4-days improved detection frequency of pesticides.

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Pearce, J. K., S. D. Golding, P. Hayes, K. A. Baublys, H. Hofmann, S. J. Herbert, and G. Gargiulo. "Gas sources and concentrations in Surat Basin shallow aquifers: a field sampling method comparison, and isotopic study." APPEA Journal 61, no. 2 (2021): 707. http://dx.doi.org/10.1071/aj20061.

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The Surat Basin hosts various industries that extract groundwater including coal seam gas (CSG), feedlots, and agriculture. With water drawdown, gas has been observed in some bores drawing groundwater from different aquifers across the Basin. While methane can occur naturally in aquifers, biogenic CSG has been extracted from the Walloon Coal Measures raising questions on the sources of gas in overlying aquifers. Current standard monitoring uses a direct fill approach to measure dissolved methane concentrations in vials; however, this approach may lose gas present above solubility levels. Water and gas sampling was performed on bores in the Springbok, Gubberamunda, Mooga, Hutton, and Precipice Sandstones, the Orallo Formation, and the Condamine Alluvium. Water bores and CSG production wells from the Walloon Coal Measures were also sampled. We compared direct fill with a closed sampling method for dissolved gas, plus a method for sampling the total free and dissolved gas in the field. Higher dissolved and total methane concentrations were measured using closed sampling methods, especially in gassy bores. The majority of our sampled aquifer gases and waters have stable isotopic signatures distinct from CSG, where methane had likely been formed insitu in shallow aquifers by primary microbial CO2 reduction or fermentation processes. In several gassy bores, the source of the methane could not be clearly identified. This study indicates that (1) current monitoring methods may be underestimating methane concentrations above identified thresholds especially in gassy bores and (2) a combination of isotopic techniques may distinguish methane sources and interaquifer disconnectivity in the majority of cases.

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Gervaix, Jonathan, Pascal Breil, Franck Poly, and Philippe Namour. "Sniffer: A Device for Sampling Gases from River." Instrumentation Mesure Métrologie 20, no. 4 (August 31, 2021): 223–33. http://dx.doi.org/10.18280/i2m.200407.

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Description and validation of a new simple, inexpensive iso-pressure device for quantitative measurements of gas emissions in river (the SNIFFER for "Sampler of Natural InFluxes of Foul Emissions from River sediment"). The Sniffer was validated, during two field campaigns, a first in winter (18/12/13 to 20/02/14) and a second in spring (16/04/14 to 14/05/14) on a stream receiving some organic matter from a combined sewer overflow. The measured CH4 emissions are of the order of 0.50 L/(m2.day). This production is far from negligible and commits us to reconsider the contribution of water systems in total greenhouse gas emissions.

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Yokochi, Reika, Ryan Bernier, Roland Purtschert, Jake C. Zappala, Yoseph Yechieli, Eilon Adar, Wei Jiang, et al. "Field Degassing as a New Sampling Method for14C Analyses in Old Groundwater." Radiocarbon 60, no. 1 (September 7, 2017): 349–66. http://dx.doi.org/10.1017/rdc.2017.64.

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AbstractRadiocarbon (14C) activity in groundwater can be used to determine subsurface residence time up to ∼40 kyr, providing crucial information on dynamic properties of groundwater and on paleoclimate. However, commonly applied sampling methods for dissolved inorganic carbon (DIC-14C) are prone to low level of modern atmospheric contamination, resulting in underestimation of groundwater ages that cluster around 30–40 kyr. We extract CO2gas from groundwater using a device originally developed for studies of noble gas radionuclides. Carbon is collected in the gas phase, eliminating the possibility of fostering microbial activities and aqueous chemical reactions during sample storage. This method collects CO2-14C and radiokrypton (81Kr and85Kr) samples simultaneously. The presence of any shorter-lived85Kr is used to evaluate the degree of atmospheric contamination during sampling or mixing of young groundwater. Most groundwater samples showed lower CO2-14C activities than those of DIC-14C, presumably due to the absence of atmospheric contamination. Samples with81Kr age exceeding 150 kyr have no detectable CO2-14C except where mixing sources of young groundwater is suspected. These field data serve as confirmations for the reliability of the newly presented sample collection and CO2-14C method, and for the outstanding roles of radiokrypton isotopes in characterizing old groundwater.

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Kar, Suraj, Thayne Montague, Antonio Villanueva-Morales, and Edward Hellman. "Measurement of Gas Exchange on Excised Grapevine Leaves Does Not Differ from In Situ Leaves, and Potentially Shortens Sampling Time." Applied Sciences 11, no. 8 (April 18, 2021): 3644. http://dx.doi.org/10.3390/app11083644.

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Use of leaf gas exchange measurement enhances the characterization of growth, yield, physiology, and abiotic stress response in grapevines. Accuracy of a crop response model depends upon sample size, which is often limited due to the prolonged time needed to complete gas exchange measurement using currently available infra-red gas analyzer systems. In this experiment, we measured mid-day gas exchange of excised and in situ leaves from field grown wine grape (Vitis vinifera) cultivars. Depending upon cultivar, we found measuring gas exchange on excised leaves under a limited time window post excision gives similar accuracy in measurement of gas exchange parameters as in situ leaves. A measurement within a minute post leaf excision can give between 96.4 and 99.5% accuracy compared to pre-excision values. When compared to previous field data, we found the leaf excision technique reduced time between consecutive gas exchange measurements by about a third compared to in situ leaves (57.52 ± 0.39 s and 86.96 ± 0.41 s, for excised and in situ, respectively). Therefore, leaf excision may allow a 50% increase in experimental sampling size. This technique could solve the challenge of insufficient sample numbers, often reported by researchers worldwide while studying grapevine leaf gas exchange using portable gas exchange systems under field conditions.

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Muravyev, Alexander V. "Gas Condensate Wells: Challenges of Sampling, Testing and Production Optimization." Energies 15, no. 15 (July 27, 2022): 5419. http://dx.doi.org/10.3390/en15155419.

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The main problem of fluid sampling during well testing of reservoirs with near-critical fluids (gas condensate and volatile oil) is due to the fact that even a small pressure drawdown usually leads to the formation of a two-phase mixture in the bottom hole area, and it is almost impossible to take representative samples with downhole samplers or a formation tester. Sampling via test-separator and the current non-separation methods are also imperfect. An alternative method—MIKS (Multiphase IsoKinetic Sampling)—of gas condensate well testing was proposed, which is based on emulsifying a multiphase flow to particles of about 1–10 μm. Thereby MIKS would eliminate the problem of particle slippage in a homogeneous flow and enables high-quality sampling directly from the flowmeter line. The initial formation fluid is characterized by the maximum value of the condensate-gas ratio (CGR). Therefore, first, the well effluent would be adjusted to the mode with the maximum CGR using a choke manifold and a multiphase flow meter. Then the flow mixture is transferred to a by-pass line with an emulsifier to achieve an isokinetic flow. Thereafter, pressure samples can be taken into pressurized sampling bottles, in which thermodynamic conditions are preset according to the flow line. The efficiency of sampling and recombining procedures allows for conducting a study of reservoir samples in the field laboratory directly on the rig and obtaining a complete PVT report even before the completion of drilling and abandonment of the well. An additional economic effect is achieved by reducing the costs of transporting and samples storage. Well test equipment setup becomes much more compact and less weight; the costs of drilling time are reduced, which is viably important for well testing on the Arctic conditions. Another major problem in the development of gas condensate reservoirs is avoiding the condensate banking around producing wells. Optimization of condensate production can be achieved by maintaining the well operation mode at maximum CGR level by means of multiphase flowmeters. The formed condensate bank can be destroyed by a combination of methods—hydraulic fracturing, followed by cycling process—purging the formation with dried gas and/or injection of methanol into the formation. Methanol can be obtained from synthesis gas as a by-product in the utilization of associated gas also at the field. The specified set of measures will allow to revive the GC wells that are losing productivity, as well as to extend the period of high productivity of new wells.

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Hao, Tian Xuan, and Meng Liu. "Study on Gas Flow Law in Goaf of Huangling No.1 Mine Fully-Mechanized Face." Advanced Materials Research 1010-1012 (August 2014): 1548–53. http://dx.doi.org/10.4028/www.scientific.net/amr.1010-1012.1548.

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The gas concentration field in goaf of Huangling No.1 Mine 304 fully-mechanized face was simulated numerically by FLUENT software with high fracture drilling or not. The results of numerical simulation were confirmed by fixed sampling method of immersed tube in goaf. Thus, the law of gas concentration field was gained, which provides the important basis for gas control of working face.

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Jiang, Leiyong, Shaji Manipurath, Gilles Bourque, and Michel Houde. "Flow field of a triple-walled gas-sampling probe with sub-cooled boiling effect." Flow Measurement and Instrumentation 18, no. 3-4 (June 2007): 156–65. http://dx.doi.org/10.1016/j.flowmeasinst.2007.06.006.

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Xue, S., Xing S. Li, and J. Xie. "A New Coal Sampling System for Measurement of Gas Content in Soft Coal Seams." Applied Mechanics and Materials 121-126 (October 2011): 2459–64. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.2459.

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Core samples or drill cuttings from boreholes drilled in coal seams are used in direct measurements of gas content in coal. In soft coal seams, core samples are difficult or sometimes impossible to obtain due to poor borehole stability such as large borehole deformation and borehole collapse, drill cuttings have to be taken and used. Due to their faster initial gas desorption rates, drill cuttings need to be taken rapidly and accurately at given positions during borehole drilling to ensure the accuracy of gas content measurements. To meet these sampling requirements of drill cuttings, a new sampling-while-drilling (SWD) system has been developed. The SWD system is based on a special design of double-tubing drill rods and a reversed circulation of pressurized air. A field test of the SWD system was carried out with satisfactory results. This paper presents the principle and results of the field test of the SWD system.

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Smith, Philip A., Timothy A. Kluchinsky, Paul B. Savage, Richard P. Erickson, Arthur P. Lee, Kenneth Williams, Michael Stevens, and Richard J. Thomas. "Traditional Sampling With Laboratory Analysis and Solid Phase Microextraction Sampling With Field Gas Chromatography/Mass Spectrometry by Military Industrial Hygienists." AIHA Journal 63, no. 3 (May 2002): 284–92. http://dx.doi.org/10.1080/15428110208984715.

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Landrø, Martin, Fredrik Hansteen, and Lasse Amundsen. "Detecting gas leakage using high-frequency signals generated by air-gun arrays." GEOPHYSICS 82, no. 2 (March 1, 2017): A7—A12. http://dx.doi.org/10.1190/geo2016-0483.1.

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Recent field experiments have demonstrated that marine air-gun arrays create acoustic energy greater than 1 kHz. We have suggested to use the high-frequency signal as a source to look for gas leakage at, for instance, a producing hydrocarbon field, or a [Formula: see text] storage site in which the field is covered by permanent acoustic sensors at the seabed, often referred to as a permanent reservoir monitoring field. The only needed modification is that the temporal sampling interval for the receivers is decreased to 0.1 ms (in contrast to the normal sampling interval of 1 or 2 ms), to ensure that the system is capable of recording signals up to 5 kHz. We suggest using numerous fixed receivers at the seabed to detect a gas chimney by simple high-pass filtering and subsequent transmission type analysis of the recorded signals. We think this method might serve as an elegant, precise, and very cost-effective way to detect gas leakage into the water layer.

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Garnett, Mark H., Josephine-Anne Newton, and Thomas C. Parker. "A HIGHLY PORTABLE AND INEXPENSIVE FIELD SAMPLING KIT FOR RADIOCARBON ANALYSIS OF CARBON DIOXIDE." Radiocarbon 63, no. 4 (June 29, 2021): 1355–68. http://dx.doi.org/10.1017/rdc.2021.49.

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AbstractRadiocarbon (14C) analysis of carbon dioxide (CO2) can be extremely useful in carbon cycle studies because it provides unique information that can infer the age and source of this greenhouse gas. Cartridges containing the CO2-adsorbing zeolite molecular sieve are small and highly portable, which makes them more suitable for field campaigns in remote locations compared to some other CO2 collection methods. However, sampling with molecular sieve cartridges usually requires additional equipment, such as an infrared gas analyser, which can reduce portability and pose limitations due to power demands. In addition, 14C analysis of CO2 is increasingly being used in field experiments which require high numbers of replicate CO2 collections, placing extra pressure on an expensive and cumbersome collection apparatus. We therefore designed and built a molecular sieve CO2 sampling kit that utilizes a small, low power CO2 sensor. We demonstrate the reliability of the new kit for the collection of CO2 samples for 14C analysis in a series of laboratory and field tests. This inexpensive sampling kit is small, light-weight, highly portable, and has low power demands, making it particularly useful for field campaigns in remote and inaccessible locations.

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Chernova, O. S. "Natural reservoir facial-petroleum field analysis for oil and gas field development." Interexpo GEO-Siberia 2, no. 1 (May 18, 2022): 9–17. http://dx.doi.org/10.33764/2618-981x-2022-2-1-9-17.

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The article describes the method of facies analysis, the relevance of which is determined by the difficulties in the study of genetic spatial heterogeneity of productive natural reservoirs by traditional, mainly "remote" methods, such as geophysical well surveys (GIS) and seismic surveys. In these conditions the facies analysis is of paramount importance: both in traditional for sedimentary strata and in its refined or new modifications. Most often, the sedimentological study uses the developments known as the facies-cyclic analysis, which predetermines a clear methodology of research, providing for a sequential separation of facies - establishment of cycles - correlation of sections - paleogeographic reconstruction, with obligatory "reverse" verification of constructions at each successive stage. However, in today's reality, the classical study of oil and gas exploration and production is practically impossible because of incomplete core sampling, fragmentation of its removal, a priori insufficient amount of core material, especially for unproductive horizons. With the mentioned non-compliance of facies-cyclic "canons" it is suggested to realize direct and direct use of facies studies, realized on the borehole cores for sedimentological and petrophysical modeling of geological natural systems. Thus, consciously removing the problems associated with the allocation of cycles, diachrony of layers of migratory nature, thus having a direct transition to the solution of practical oil and gas problems, based on a reliable facies basis. The method is developed for deep productive horizons, inaccessible to direct observation, in conditions of limited actual data (small number of cores).

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Bai, Hsunling, Chungsying Lu, Kuan-Foo Chang, and Guor-Cheng Fang. "Sources of sampling error for field measurement of nitric acid gas by a denuder system." Atmospheric Environment 37, no. 7 (March 2003): 941–47. http://dx.doi.org/10.1016/s1352-2310(02)00972-x.

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Ifezue, D., and F. H. Tobins. "Subsea Sampling Mitigation of ASD Failures During Commissioning of a New Oil/Gas Production Field." Journal of Failure Analysis and Prevention 14, no. 5 (September 26, 2014): 675–82. http://dx.doi.org/10.1007/s11668-014-9876-5.

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Smith, Philip A., David Koch, Gary L. Hook, Richard P. Erickson, Carmela R. Jackson Lepage, Haley D. M. Wyatt, Geoffrey Betsinger, and Brian A. Eckenrode. "Detection of gas-phase chemical warfare agents using field-portable gas chromatography–mass spectrometry systems: instrument and sampling strategy considerations." TrAC Trends in Analytical Chemistry 23, no. 4 (April 2004): 296–306. http://dx.doi.org/10.1016/s0165-9936(04)00405-4.

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Shah, Adil, Joseph R. Pitt, Hugo Ricketts, J. Brian Leen, Paul I. Williams, Khristopher Kabbabe, Martin W. Gallagher, and Grant Allen. "Testing the near-field Gaussian plume inversion flux quantification technique using unmanned aerial vehicle sampling." Atmospheric Measurement Techniques 13, no. 3 (March 30, 2020): 1467–84. http://dx.doi.org/10.5194/amt-13-1467-2020.

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Abstract. Methane emission fluxes from many facility-scale sources may be poorly quantified, potentially leading to uncertainties in the global methane budget. Accurate atmospheric measurement-based flux quantification is urgently required to address this. This paper describes the first test (using unbiased sampling) of a near-field Gaussian plume inversion (NGI) technique, suitable for facility-scale flux quantification, using a controlled release of methane gas. Two unmanned-aerial-vehicle (UAV) platforms were used to perform 22 flight surveys downwind of a point-source methane gas release from a regulated cylinder with a flowmeter. One UAV was tethered to an instrument on the ground, while the other UAV carried an on-board prototype instrument (both of which used the same near-infrared laser technology). Both instruments were calibrated using certified standards to account for variability in the instrumental gain factor, assuming fixed temperature and pressure. Furthermore, a water vapour correction factor, specifically calculated for the instrument, was applied and is described here in detail. We also provide guidance on potential systematic uncertainties associated with temperature and pressure, which may require further characterisation for improved measurement accuracy. The NGI technique was then used to derive emission fluxes for each UAV flight survey. We found good agreement of most NGI fluxes with the known controlled emission flux, within uncertainty, verifying the flux quantification methodology. The lower and upper NGI flux uncertainty bounds were, on average, 17 %±10(1σ) % and 227 %±98(1σ) % of the controlled emission flux, respectively. This range of conservative uncertainty bounds incorporate factors including the variability in the position of the time-invariant plume and potential for under-sampling. While these average uncertainties are large compared to methods such as tracer dispersion, we suggest that UAV sampling can be highly complementary to a toolkit of flux quantification approaches and may be a valuable alternative in situations where site access for tracer release is problematic. We see tracer release combined with UAV sampling as an effective approach in future flux quantification studies. Successful flux quantification using the UAV sampling methodology described here demonstrates its future utility in identifying and quantifying emissions from methane sources such as oil and gas extraction infrastructure facilities, livestock agriculture, and landfill sites, where site access may be difficult.

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Kreisberg, N. M., D. R. Worton, Y. Zhao, G. Isaacman, A. H. Goldstein, and S. V. Hering. "Development of an automated high temperature valveless injection system for on-line gas chromatography." Atmospheric Measurement Techniques Discussions 7, no. 7 (July 23, 2014): 7531–67. http://dx.doi.org/10.5194/amtd-7-7531-2014.

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Abstract. A reliable method of sample introduction is presented for on-line gas chromatography with a special application to in-situ field portable atmospheric sampling instruments. A traditional multi-port valve is replaced with a controlled pressure switching device that offers the advantage of long term reliability and stable sample transfer efficiency. An engineering design model is presented and tested that allows customizing the interface for other applications. Flow model accuracy is within measurement accuracy (1%) when parameters are tuned for an ambient detector and 15% accurate when applied to a vacuum based detector. Laboratory comparisons made between the two methods of sample introduction using a thermal desorption aerosol gas chromatograph (TAG) show approximately three times greater reproducibility maintained over the equivalent of a week of continuous sampling. Field performance results for two versions of the valveless interface used in the in-situ instrument demonstrate minimal trending and a zero failure rate during field deployments ranging up to four weeks of continuous sampling. Extension of the VLI to dual collection cells is presented with less than 3% cell-to-cell carry-over.

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Midgley, G. F., M. Veste, D. J. Don Willert, G. W. Davis, M. Steinberg, and L. W. Powrie. "Comparative field performance of three different gas exchange systems." Bothalia 27, no. 1 (October 7, 1997): 83–89. http://dx.doi.org/10.4102/abc.v27i1.662.

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We compared portable and continuously monitoring gas exchange systems under field conditions, using Protea glabra Thunb. as a test species. The aim was to determine if the same patterns of gas exchange and ancillary parameters could be obtained with rather different measurement systems, and whether the same interpretation and conclusions about environmental control of gas exchange could be drawn. The following systems were compared: 1, a ‘closed’ portable 1RGA manufactured by Ll-Cor (LI-6200); 2, an ‘open’ portable porometer manufactured by Walz; and 3, a continuously monitoring minicuvette system with temperature control facility, also manufactured by Walz. All three systems yielded similar diurnal curves for CO2 uptake, although absolute flux values for the minicuvette system were lower than those obtained for the portable systems. This was likely due to stem respiration and self-shading of leaves on the shoot enclosed in the minicuvette. Differences in sampling technique between the two portable systems, primarily with regard to changes in leaf orientation, resulted in some differences in absolute values of gas fluxes and ancillary parameters such as leaf temperature and leaf to air vapour pressure difference. However, data from all three systems allowed similar interpretations to be made about the environmental dependencies of gas exchange patterns. It appears that each system has certain drawbacks associated with widely varying field conditions. A combination of portable and continuous monitoring techniques would seem to be the most powerful approach to investigating the gas exchange patterns of terrestrial plants in their natural environment.

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Kreisberg, N. M., D. R. Worton, Y. Zhao, G. Isaacman, A. H. Goldstein, and S. V. Hering. "Development of an automated high-temperature valveless injection system for online gas chromatography." Atmospheric Measurement Techniques 7, no. 12 (December 12, 2014): 4431–44. http://dx.doi.org/10.5194/amt-7-4431-2014.

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Abstract. A reliable method of sample introduction is presented for online gas chromatography with a special application to in situ field portable atmospheric sampling instruments. A traditional multi-port valve is replaced with a valveless sample introduction interface that offers the advantage of long-term reliability and stable sample transfer efficiency. An engineering design model is presented and tested that allows customizing this pressure-switching-based device for other applications. Flow model accuracy is within measurement accuracy (1%) when parameters are tuned for an ambient-pressure detector and 15% accurate when applied to a vacuum-based detector. Laboratory comparisons made between the two methods of sample introduction using a thermal desorption aerosol gas chromatograph (TAG) show that the new interface has approximately 3 times greater reproducibility maintained over the equivalent of a week of continuous sampling. Field performance results for two versions of the valveless interface used in the in situ instrument demonstrate typically less than 2% week−1 response trending and a zero failure rate during field deployments ranging up to 4 weeks of continuous sampling. Extension of the valveless interface to dual collection cells is presented with less than 3% cell-to-cell carryover.

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Storchi-Bergmann, Thaisa. "Inflows and Outflows in Nearby AGN from Integral Field Spectroscopy." Proceedings of the International Astronomical Union 5, S267 (August 2009): 290–98. http://dx.doi.org/10.1017/s1743921310006502.

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AbstractI report recent results on the kinematics of the inner few hundred parsecs (pc) around nearby active galactic nuclei (AGN) at a sampling of a few pc to a few tens of pc, using optical and near-infrared (near-IR) integral field spectroscopy obtained with the Gemini telescopes. The stellar kinematics of the hosts — comprised mostly of spiral galaxies — are dominated by circular rotation in the plane of the galaxy. Inflows with velocities of ~50 km s−1 have been observed along nuclear spiral arms in (optical) ionized gas emission for low-luminosity AGN and in (near-IR) molecular gas emission for higher-luminosity AGN. We have also observed gas rotating in the galaxy plane, sometimes in compact (few tens of pc) disks which may be fuelling the AGN. Outflows have been observed mostly in ionized gas emission from the narrow-line region, whose flux distributions and kinematics frequently correlate with radio flux distributions. Channel maps along the emission-line profiles reveal velocities as high as ~ 600 km s−1. Mass outflow rates in ionized gas range from 10−2 to 10−3M⊙ yr−1 and are 10–100 times larger than the mass accretion rates on to the AGN, supporting an origin for the bulk of the outflow in gas from the galaxy plane entrained by a nuclear jet or accretion disk wind.

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Godri, K. J., G. J. Evans, J. Slowik, A. Knox, J. Abbatt, J. Brook, T. Dann, and E. Dabek-Zlotorzynska. "Evaluation and application of a semi-continuous chemical characterization system for water soluble inorganic PM<sub>2.5</sub> and associated precursor gases." Atmospheric Measurement Techniques Discussions 1, no. 1 (November 26, 2008): 205–48. http://dx.doi.org/10.5194/amtd-1-205-2008.

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Abstract. Water soluble inorganic particles components (Cl−, SO42−, NO3−, and NH4+) and concentrations of their associated precursor gases (HCl, SO2, HNO3, NH3) were semi-continuously measured using the Dionex Gas Particle Ion Chromatography (GPIC) system. Sampling was conducted adjacent to a high traffic street in downtown Toronto, Canada from June 2006 to March 2007. This study evaluated the precision and accuracy of field sampling measurements with the GPIC both relative to filter based measurements and other co-located semi-continuous instruments (R&P 8400N Nitrate Monitor, API Fluorescent SO2 Gas Analyzer, and Aerodyne C-ToF-AMS). High temporal resolution PM2.5 mass reconstruction is presented by combining GPIC measured inorganic species concentrations and Sunset Laboratory OCEC Analyzer determined organics concentrations. Field sampling results were also examined for seasonal and diurnal variations. HNO3 and particulate nitrate exhibited diurnal variation and strong partitioning to the gas phase was observed during the summer. Ammonia and particulate ammonium also demonstrated seasonal differences in their diurnal profiles. However, particulate sulphate and SO2 showed no diurnal variation regardless of season suggesting dominant transport from regional sources throughout the year.

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Godri, K. J., G. J. Evans, J. Slowik, A. Knox, J. Abbatt, J. Brook, T. Dann, and E. Dabek-Zlotorzynska. "Evaluation and application of a semi-continuous chemical characterization system for water soluble inorganic PM<sub>2.5</sub> and associated precursor gases." Atmospheric Measurement Techniques 2, no. 1 (March 25, 2009): 65–80. http://dx.doi.org/10.5194/amt-2-65-2009.

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Abstract. Water soluble inorganic particles components (Cl−, SO42−, NO3−, and NH4+) and concentrations of their associated precursor gases (HCl, SO2, HNO3, NH3) were semi-continuously measured using the Dionex Gas Particle Ion Chromatography (GPIC) system. Sampling was conducted adjacent to a high traffic street in downtown Toronto, Canada from June 2006 to March 2007. This study evaluated the precision and accuracy of field sampling measurements with the GPIC both relative to filter based measurements and other co-located semi-continuous instruments (R&P 8400N Nitrate Monitor, API Fluorescent SO2 Gas Analyzer, and Aerodyne C-ToF-AMS). High temporal resolution PM2.5 mass reconstruction is presented by combining GPIC measured inorganic species concentrations and Sunset Laboratory OCEC Analyzer determined organics concentrations. Field sampling results were also examined for seasonal and diurnal variations. HNO3 and particulate nitrate exhibited diurnal variation and strong partitioning to the gas phase was observed during the summer. Ammonia and particulate ammonium also demonstrated seasonal differences in their diurnal profiles. However, particulate sulphate and SO2 showed no diurnal variation regardless of season suggesting dominant transport from regional sources throughout the year.

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Vasilev, Yu V., D. A. Misyurev, and A. V. Filatov. "ANTHROPOGENIC INFLUENCE OF THE KOMSOMOLSK OIL AND GAS CONDENSATE FIELD ON MODERN DEFORMATION PROCESSES." Oil and Gas Studies, no. 2 (May 1, 2018): 11–20. http://dx.doi.org/10.31660/0445-0108-2018-2-11-20.

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The authors created a geodynamical polygon on the Komsomolsk oil and gas condensate field to ensure the industrial safety of oil and gas production facilities. The aim of its creation is mul-tiple repeated observations of recent deformation processes. Analysis and interpretation of the results of geodynamical monitoring which includes class II leveling, satellite observations, radar interferometry, exploitation parameters of field development provided an opportunity to identify that the conditions for the formation of recent deformations of the earth’s surface is an anthropogenic factor. The authors identified the relationship between the formation of subsidence trough of the earth’s surface in the eastern part of the field with the dynamics of accumulated gas sampling and the fall of reservoir pressures along the main reservoir PK1 (Cenomanian stage).

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Duncan, Candice M., Jon Mainhagu, Dan Lin, and Mark L. Brusseau. "Analysis of trichloroethene vapour in soil-gas samples using solid-sorbent tubes with gas chromatography/mass spectrometry." Environmental Chemistry 14, no. 8 (2017): 495. http://dx.doi.org/10.1071/en17161.

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Environmental contextChlorinated chemicals are priority contaminants that pose significant risk to human health, and require state-of-the-art sampling techniques for varying matrices. A soil-gas sampling method was developed for the quantification of vapours of trichloroethene, a major chlorinated contaminant, present just above the groundwater zone. The method addresses sampling times, volumes and low-level trichloroethene concentrations. AbstractA sampling method for determining vapour concentrations of chlorinated contaminants, specifically trichloroethene (TCE), present in the vadose zone has been developed, and was applied at the Tucson International Airport Area Superfund site. The method, modified from the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods # 1022 for ambient-air sampling of TCE, is targeted to situations requiring cost-effective sample collection, particularly for cases in which concentrations are at or below maximum contaminant. In our method, TCE vapour is sampled using a solid-sorbent tube. Gas chromatography with mass spectrometry is used to confirm and quantify the presence of TCE. The results of laboratory tests demonstrate a maximum TCE vapour load of ~22 mg before breakthrough to the secondary sorbent-tube section, and an extraction efficiency of ~97%. The results of a performance comparison test conducted in the field show that concentrations obtained with the sorbent tube samplers (~5 μg/L) are similar to those obtained with the use of standard summa canisters (~3 μg/L). The quantitative detection limit for the new method was 0.03 μg/L under the operative conditions, a significant improvement on current analytical methods. The results indicate that use of the sorbent-tube method will be effective for vapour sample collection at sites contaminated with volatile organic compounds, particularly in characterising low concentrations for applications such as assessing groundwater contamination risk and the need for remedial action via soil vapour extraction or other methods.

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Levine, Audrey D., and Mark J. Benotti. "Baseline groundwater quality in unconventional oil and gas fields." Water Supply 15, no. 6 (June 11, 2015): 1166–78. http://dx.doi.org/10.2166/ws.2015.078.

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In recent years, expansion of unconventional oil and gas production has prompted significant interest in potential impacts on drinking water resources. In many cases, water quality investigations rely on access to landowner water wells to develop baseline data prior to drilling; respond to spills, complaints, or incidents; or evaluate potential impacts due to drilling, completion, hydraulic fracturing, water management, or well operation. However, differences in water well construction, operation, maintenance, and wellhead protection practices can complicate sampling efforts and introduce artifacts that might confound interpretation of results and definition of baseline conditions. The frequency of sampling and the types of analyses also vary from site to site, ranging from basic field parameters such as conductivity, pH, and water level to comprehensive analyses of organics, inorganics, radionuclides, gases, stable isotopes, and microorganisms. Regulatory agencies may also specify required analytical parameters and monitoring frequency. This paper highlights some of the challenges associated with deriving baseline data from different types of wells and provides preliminary data on the use of chemical fingerprinting to differentiate sources of waterborne contaminants.

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Gardner, W. Payton, Stephen J. Bauer, and Scott Broome. "Investigating Fracture Network Deformation Using Noble Gas Release." Geofluids 2021 (May 19, 2021): 1–16. http://dx.doi.org/10.1155/2021/6697819.

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We investigate deformation mechanics of fracture networks in unsaturated fractured rocks from subsurface conventional detonation using dynamic noble gas measurements and changes in air permeability. We dynamically measured the noble gas isotopic composition and helium exhalation of downhole gas before and after a large subsurface conventional detonation. These noble gas measurements were combined with measurements of the subsurface permeability field from 64 discrete sampling intervals before and after the detonation and subsurface mapping of fractures in borehole walls before well completion. We saw no observable increase in radiogenic noble gas release from either an isotopic composition or a helium exhalation point of view. Large increases in permeability were observed in 13 of 64 discrete sampling intervals. Of the sampling intervals which saw large increases in flow, only two locations did not have preexisting fractures mapped at the site. Given the lack of noble gas release and a clear increase in permeability, we infer that most of the strain accommodation of the fractured media occurred along previously existing fractures, rather than the creation of new fractures, even for a high strain rate event. These results have significant implications for how we conceptualize the deformation of rocks with fracture networks above the percolation threshold, with application to a variety of geologic and geological engineering problems.

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Schmithausen, Alexander, Manfred Trimborn, and Wolfgang Büscher. "Methodological Comparison between a Novel Automatic Sampling System for Gas Chromatography versus Photoacoustic Spectroscopy for Measuring Greenhouse Gas Emissions under Field Conditions." Sensors 16, no. 10 (October 3, 2016): 1638. http://dx.doi.org/10.3390/s16101638.

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Li, Chaoqun, Wenting Han, Manman Peng, Mengfei Zhang, Xiaomin Yao, Wenshuai Liu, and Tonghua Wang. "An Unmanned Aerial Vehicle-Based Gas Sampling System for Analyzing CO2 and Atmospheric Particulate Matter in Laboratory." Sensors 20, no. 4 (February 15, 2020): 1051. http://dx.doi.org/10.3390/s20041051.

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We developed and tested an unmanned aerial vehicle-based gas sampling system (UGSS) for collecting gases and atmospheric particulate matter (PM). The system applies an alternative way of collecting both vertical and horizontal transects of trace gases in order to analyze them in the laboratory. To identify the best position of the UGSS intake port, aerodynamic flow simulations and experimental verifications of propeller airflow were conducted with an unmanned aerial vehicle (UAV) in hover mode. The UGSS will automatically replace the original gas in the system with gas from a target location to avoid the original gas being stored in the air bags. Experimental results show that the UGSS needs 5 s to replace the system’s own original gas using its pump. CO2 and PM2.5/10 above the corn field are used as the test species to validate the accuracy of the CO2 gas and PM concentrations collected by UGSS. Deming regression analyses showed good agreement between the measurements from the UGSS and the ground sampling station (y = 1.027x – 11.239, Pearson’s correlation coefficient of 0.98 for CO2; y = 0.992x + 0.704, Pearson’s correlation coefficient of 0.99 for PM).The UGSS provides a measuring method that actively collects gases and PM for manual analyses in the laboratory.

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Khamidov, B. N., and T. I. Samukov. "Obtaining mixed solvents from gas condensate." World of petroleum products 04 (2022): 22–24. http://dx.doi.org/10.32758/2782-3040-2022-0-4-22-24.

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To obtain an extraction solvent ГКЭКС-С3-60/95 for the extraction of vegetable oils, stable gas condensates of the Shurtan natural gas field were used. The method of rectification was successfully carried out and hydrocarbon fractions were obtained on the apparatus for rectifying oil (ARN-2). Fraction sampling from gas condensate was carried out up to 95°C. Based on the analysis of the parameters (temperature regime, reflux ratio, number of theoretical plates, etc.) for obtaining solvents at ARN-2., a basic technological scheme for the industrial production of an extraction solvent from gas condensate was developed and their physicochemical properties were studied.

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Rajasekar, Panneerselvam, and James Arputha Vijaya Selvi. "Sensing and Analysis of Greenhouse Gas Emissions from Rice Fields to the Near Field Atmosphere." Sensors 22, no. 11 (May 30, 2022): 4141. http://dx.doi.org/10.3390/s22114141.

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Greenhouse gas (GHG) emissions from rice fields have huge effects on climate change. Low-cost systems and management practices to quantify and reduce GHGs emission rates are needed to achieve a better climate. The typical GHGs estimation processes are expensive and mainly depend on high-cost laboratory equipment. This study introduces a low-cost sensor-based GHG sampling and estimation system for rice fields. For this, a fully automatic gas chamber with a sensor-integrated gas accumulator and quantifier unit was designed and implemented to study its performance in the estimation efficiency of greenhouse gases (CH4, N2O, and CO2) from rice fields for two crop seasons. For each crop season, three paddy plots were prepared at the experimental site and then subjected to different irrigation methods (continuous flooding (CF), intermittent flooding (IF), and controlled intermittent flooding (CIF)) and fertilizer treatments to study the production and emission rates of GHGs throughout the crop growing season at regular intervals. A weather station was installed on the site to record the seasonal temperature and rainfall events. The seasonal total CH4 emission was affected by the effects of irrigation treatments. The mean CH4 emission in the CIF field was smaller than in other treatments. CH4 and N2O emission peaks were high during the vegetative and reproductive phases of rice growth, respectively. The results indicated that CIF treatment is most suitable in terms of rice productivity and higher water use efficiency. The application of nitrogen fertilizers produced some peaks in N2O emissions. On the whole, the proposed low-cost GHGs estimation system performed well during both crop seasons and it was found that the adaption of CIF treatment in rice fields could significantly reduce GHG emissions and increase rice productivity. The research results also suggested some mitigation strategies that could reduce the production of GHGs from rice fields.

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Chen, Demin, Wei Long, Yanyan Li, and Rui Zhang. "Study on Change Rules of Factors Affecting Gas Loss during Coalbed Air Reverse Circulation Sampling." Advances in Civil Engineering 2021 (April 20, 2021): 1–15. http://dx.doi.org/10.1155/2021/5550726.

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The gas loss in sampling is the root of coalbed gas content measurement error. The pressure and particle size have a significant impact on the gas loss. Using the self-developed coal particle pneumatic pipeline transportation experimental system, this study investigated the pressure and particle size changes in the sampling pipeline. It is found that the sampling process can be divided into four stages: no flow field stage, sample outburst stage, stable conveying stage, and tail purging stage. The extreme pressure in the sampling pipeline appears at the sample outburst stage; and the pressure in the pipeline has levelled off after sharp decrease in the stable conveying stage. It is also found that the extreme pressure increases first and then decreases with the increase of particle size. The duration of outburst stage is negatively correlated with particle size, and that of stable conveying stage is positively correlated with particle size. In addition, the results show that the loss rate of 1–3 mm particles is the smallest after the test but that particles less than 1 mm increase by about two times and particles greater than 3 mm decrease by more than three times. The study also shows that the particle size distribution of coal samples is a single peak with left skew distribution, and the gas reverse circulation sampling test does not change the location of the peak but makes it higher and sharper. The single size coal sample is more likely to collide than the mixture. This study can help to advance the understanding of impact factors on gas loss during reverse circulation sampling.

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Hook, Gary L., Gregory L. Kimm, Tara Hall, and Philip A. Smith. "Solid-phase microextraction (SPME) for rapid field sampling and analysis by gas chromatography-mass spectrometry (GC-MS)." TrAC Trends in Analytical Chemistry 21, no. 8 (August 2002): 534–43. http://dx.doi.org/10.1016/s0165-9936(02)00708-2.

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Aikawa, Masahide, Motoharu Suzuki, Takatoshi Hiraki, Motonori Tamaki, Akira Kondo, Hitoshi Mukai, and Kentato Murano. "Intensive Field Survey of Aerosol and Gas Concentrations with 6-h Interval Sampling in Winter in Japan." Water, Air, and Soil Pollution 182, no. 1-4 (December 20, 2006): 91–105. http://dx.doi.org/10.1007/s11270-006-9324-6.

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Moridis, G. J. J., T. S. S. Collett, M. Pooladi-Darvish, S. Hancock, C. Santamarina, R. Boswell, T. Kneafsey, et al. "Challenges, Uncertainties, and Issues Facing Gas Production From Gas-Hydrate Deposits." SPE Reservoir Evaluation & Engineering 14, no. 01 (February 21, 2011): 76–112. http://dx.doi.org/10.2118/131792-pa.

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Summary The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas-hydrate (GH) petroleum system; to discuss advances, requirements, and suggested practices in GH prospecting and GH deposit characterization; and to review the associated technical, economic, and environmental challenges and uncertainties, which include the following: accurate assessment of producible fractions of the GH resource; development of methods for identifying suitable production targets; sampling of hydrate-bearing sediments (HBS) and sample analysis; analysis and interpretation of geophysical surveys of GH reservoirs; well-testing methods; interpretation of well-testing results; geomechanical and reservoir/well stability concerns; well design, operation, and installation; field operations and extending production beyond sand-dominated GH reservoirs; monitoring production and geomechanical stability; laboratory investigations; fundamental knowledge of hydrate behavior; the economics of commercial gas production from hydrates; and associated environmental concerns.

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Villareal, Steven, Julian Pop, François Bernard, Martin Baxter, Ahmad Hakam, Andy Firth, Amanda Megat, Scott Fey, Shahid Azizul Haq, and Nitin Vahi. "Sampling While Drilling: An Emerging Technology." SPE Reservoir Evaluation & Engineering 17, no. 02 (March 10, 2014): 128–40. http://dx.doi.org/10.2118/159503-pa.

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Summary Even though it is the early days of the realization of sampling-while-drilling (SWD) as a service, a picture of what might be achievable in practice is beginning to emerge. Previous SWD experience has demonstrated that the sampling process may be controlled sufficiently well that relatively clean samples may be acquired when sampling aquifers drilled with water-based muds (WBMs), and it has demonstrated that the SWD tool and sensors used are capable of operating effectively while withstanding the drilling process. On the basis of this experience, operational guidelines have been formulated, particularly regarding the most opportune time to sample during the drilling process. The first part of the paper describes SWD in a high-angle appraisal well drilled to assess the continuity and quality of several target sands and to establish the degree of continuity of these sands with the main field. The well was drilled by use of an oil-based mud (OBM). Samples would be acquired after the well had reached total depth so that the most appropriate sampling points could be identified by means of openhole logs. Multiple water-, oil-, and gas-bearing formations were identified. Sampling duties were split between the SWD tool and a drillpipe-conveyed wireline sampling (WLS) tool in an attempt to rationalize the sampling program of the well. To enable a comparison of the relative performance of the two tools, two oil-sampling stations were chosen where multiple samples would be acquired under similar operating conditions by both tools. In addition, water samples were collected at two stations by the SWD tool and scanning was performed at one (wet) gas station to confirm the formation-fluid type. Laboratory analysis of the oil samples at the common stations showed that the contaminations and fluid properties of the samples acquired by the two sampling tools were very similar. The second part of this paper describes results obtained in an appraisal well and sidetrack in a different field. Both pilot and sidetrack were high-angle wells drilled by use of OBMs. The purpose of these wells was to identify and evaluate the commercial potential of unproduced hydrocarbon-bearing zones. Both wells were drilled to total depth before conducting sampling operations, and no wireline operations were planned in either well. Five oil samples were acquired in the pilot well in two zones, and four oil samples and two water samples were recovered in the sidetrack. The results obtained during the SWD operations described suggest that it is possible to consistently acquire quality formation-fluid samples during drilling operations, even under less-than-optimal sampling conditions and strict time-on-station constraints. The quality of the samples recovered is sufficient to perform reliable pressure/volume/temperature (PVT) analyses.

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Frausto-Vicencio, Isis, Alondra Moreno, Hugh Goldsmith, Ying-Kuang Hsu, and Francesca M. Hopkins. "Characterizing the Performance of a Compact BTEX GC-PID for Near-Real Time Analysis and Field Deployment." Sensors 21, no. 6 (March 17, 2021): 2095. http://dx.doi.org/10.3390/s21062095.

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In this study, we test the performance of a compact gas chromatograph with photoionization detector (GC-PID) and optimize the configuration to detect ambient (sub-ppb) levels of benzene, toluene, ethylbenzene, and xylene isomers (BTEX). The GC-PID system was designed to serve as a relatively inexpensive (~10 k USD) and field-deployable air toxic screening tool alternative to conventional benchtop GCs. The instrument uses ambient air as a carrier gas and consists of a Tenax-GR sorbent-based preconcentrator, a gas sample valve, two capillary columns, and a photoionization detector (PID) with a small footprint and low power requirement. The performance of the GC-PID has been evaluated in terms of system linearity and sensitivity in field conditions. The BTEX-GC system demonstrated the capacity to detect BTEX at levels as high as 500 ppb with a linear calibration range of 0–100 ppb. A detection limit lower than 1 ppb was found for all BTEX compounds with a sampling volume of 1 L. No significant drift in the instrument was observed. A time-varying calibration technique was established that requires minimal equipment for field operations and optimizes the sampling procedure for field measurements. With an analysis time of less than 15 min, the compact GC-PID is ideal for field deployment of background and polluted atmospheres for near-real time measurements of BTEX. The results highlight the application of the compact and easily deployable GC-PID for community monitoring and screening of air toxics.

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Lee, James D., Stephen D. Mobbs, Axel Wellpott, Grant Allen, Stephane J. B. Bauguitte, Ralph R. Burton, Richard Camilli, et al. "Flow rate and source reservoir identification from airborne chemical sampling of the uncontrolled Elgin platform gas release." Atmospheric Measurement Techniques 11, no. 3 (March 27, 2018): 1725–39. http://dx.doi.org/10.5194/amt-11-1725-2018.

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Abstract. An uncontrolled gas leak from 25 March to 16 May 2012 led to evacuation of the Total Elgin wellhead and neighbouring drilling and production platforms in the UK North Sea. Initially the atmospheric flow rate of leaking gas and condensate was very poorly known, hampering environmental assessment and well control efforts. Six flights by the UK FAAM chemically instrumented BAe-146 research aircraft were used to quantify the flow rate. The flow rate was calculated by assuming the plume may be modelled by a Gaussian distribution with two different solution methods: Gaussian fitting in the vertical and fitting with a fully mixed layer. When both solution methods were used they compared within 6 % of each other, which was within combined errors. Data from the first flight on 30 March 2012 showed the flow rate to be 1.3 ± 0.2 kg CH4 s−1, decreasing to less than half that by the second flight on 17 April 2012. δ13CCH4 in the gas was found to be −43 ‰, implying that the gas source was unlikely to be from the main high pressure, high temperature Elgin gas field at 5.5 km depth, but more probably from the overlying Hod Formation at 4.2 km depth. This was deemed to be smaller and more manageable than the high pressure Elgin field and hence the response strategy was considerably simpler. The first flight was conducted within 5 days of the blowout and allowed a flow rate estimate within 48 h of sampling, with δ13CCH4 characterization soon thereafter, demonstrating the potential for a rapid-response capability that is widely applicable to future atmospheric emissions of environmental concern. Knowledge of the Elgin flow rate helped inform subsequent decision making. This study shows that leak assessment using appropriately designed airborne plume sampling strategies is well suited for circumstances where direct access is difficult or potentially dangerous. Measurements such as this also permit unbiased regulatory assessment of potential impact, independent of the emitting party, on timescales that can inform industry decision makers and assist rapid-response planning by government.

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Kuantama, Endrowednes, Radu Tarca, Simona Dzitac, Ioan Dzitac, Tiberiu Vesselenyi, and Ioan Tarca. "The Design and Experimental Development of Air Scanning Using a Sniffer Quadcopter." Sensors 19, no. 18 (September 6, 2019): 3849. http://dx.doi.org/10.3390/s19183849.

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This study presents a detailed analysis of an air monitoring development system using quadcopters. The data collecting method is based on gas dispersion investigation to pinpoint the gas source location and determine the gas concentration level. Due to its flexibility and low cost, a quadcopter was integrated with air monitoring sensors to collect the required data. The analysis started with the sensor placement on the quadcopter and their correlation with the generated vortex. The reliability and response time of the sensor used determine the duration of the data collection process. The dynamic nature of the environment makes the technique of air monitoring of topmost concern. The pattern method has been adapted to the data collection process in which area scanning was marked using a point of interest or grid point. The experiments were done by manipulating a carbon monoxide (CO) source, with data readings being made in two ways: point source with eight sampling points arranged in a square pattern, and non-point source with 24 sampling points in a grid pattern. The quadcopter collected data while in a hover state with 10 s sampling times at each point. The analysis of variance method (ANOVA) was also used as the statistical algorithm to analyze the vector of gas dispersion. In order to tackle the uncertainty of wind, a bivariate Gaussian kernel analysis was used to get an estimation of the gas source area. The result showed that the grid pattern measurement was useful in obtaining more accurate data of the gas source location and the gas concentration. The vortex field generated by the propeller was used to speed up the accumulation of the gas particles to the sensor. The dynamic nature of the wind caused the gas flow vector to change constantly. Thus, more sampling points were preferred, to improve the accuracy of the gas source location prediction.

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Pikmann, Julia, Lasse Moormann, Frank Drewnick, and Stephan Borrmann. "The AERosol and TRACe gas Collector (AERTRACC): an online-measurement-controlled sampler for source-resolved emission analysis." Atmospheric Measurement Techniques 16, no. 5 (March 13, 2023): 1323–41. http://dx.doi.org/10.5194/amt-16-1323-2023.

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Abstract. Probing sources of atmospheric pollution in complex environments often leads to the measurement and sampling of a mixture of different aerosol types due to fluctuations of the emissions or the atmospheric transport situation. Here, we present the AERosol and TRACe gas Collector (AERTRACC), a system for sampling various aerosol types independently on separate sampling media, controlled by parallel online measurements of particle, trace gas, and meteorological variables, like particle number or mass concentration, particle composition, trace gas concentration, and wind direction and speed. AERTRACC is incorporated into our mobile laboratory (MoLa) which houses online instruments that measure various physical and chemical aerosol properties, as well as trace gas concentrations. Based on preparatory online measurements with the whole MoLa setup, suitable parameters measured by these instruments are used to define individual sampling conditions for each targeted aerosol type using a dedicated software interface. Through evaluation of continuously online-measured data with regard to the sampling conditions, the sampler automatically switches between sampling and non-sampling for each of up to four samples, which can be collected in parallel. The particle phase and gas phase of each aerosol type, e.g., source emissions and background, are sampled onto separate filters with PM1 and PM10 cutoffs and thermal desorption tubes, respectively. Information on chemical compounds in the sampled aerosol is obtained by means of thermal desorption chemical ionization mass spectrometry (TD-CIMS) as the analysis method. The design, operation, and characterization of the sampler are presented. For in-field validation, wood-fired pizza oven emissions were sampled as targeted emissions separately from ambient background. Results show that the combination of well-chosen sampling conditions allows more efficient and effective separation of source-related aerosols from the background, as seen by the increases of particle number and mass concentration and concentration of organic aerosol types, with minimized loss of sampling time compared to alternative sampling strategies.

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Lecharlier, Aurore, Hervé Carrier, Brice Bouyssiere, Guilhem Caumette, Pierre Chiquet, and Isabelle Le Hécho. "Novel field-portable high-pressure adsorbent tube sampler prototype for the direct in situ preconcentration of trace compounds in gases at their working pressures: application to biomethane." RSC Advances 12, no. 16 (2022): 10071–87. http://dx.doi.org/10.1039/d2ra00601d.

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Antonov, Dimitar, Kremena Ivanova, Bistra Kunovska, Desislava Djunakova, Iren Ilieva, Polina Andreeva, Sava Kolev, and Aleksey Benderev. "Spatial Sampling Design for the Geogenic Radon Potential Survey in Sliven Province, Bulgaria." Proceedings of the Bulgarian Academy of Sciences 75, no. 4 (May 2, 2022): 561–69. http://dx.doi.org/10.7546/crabs.2022.04.11.

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The development of a methodology for the geogenic radon potential (GRP) mapping based on soil gas radon and soil gas permeability field measurements is among the main objectives in the determination of “radon priority areas” in Bulgaria. One of the key elements of the methodology is to define as accurately as possible, areas of risk for the presence of radon gas (222Rn) on the map. This study presents an approach to spatial sampling for the geogenic radon potential survey in Sliven Province, Bulgaria. The district is characterised by its very complex geological settings, represented by rocks of different age and mineral and chemical compositions. The proposed methodology defined a sampling frame of province radon map, prepared on the base of indoor radon measurement and the complex sampling scheme of random points. The parcel-level GIS was used for establishing the sample frame of 5×5 km polygons on the territory of the province. The IBM SPSS Complex Samples Module was applied for planning the survey’s polygons by drawing sample units according to the spatial design. The spatial relationship between indoor radon concentration and geological information was analysed for the sampling scheme construction by the polygons. The latter serve as sampling units, allowing both indoor radon concentration and geological data to be linked. The results show that the applied spatial sampling approach allows controlling the specific environmental conditions, in terms of their specificity, variability, and distribution.

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Turnbull, J., D. Guenther, A. Karion, C. Sweeney, E. Anderson, A. Andrews, J. Kofler, et al. "An integrated flask sample collection system for greenhouse gas measurements." Atmospheric Measurement Techniques Discussions 5, no. 3 (June 8, 2012): 4077–97. http://dx.doi.org/10.5194/amtd-5-4077-2012.

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Abstract. A one hour integrated flask sampling system to collect air in automated NOAA/ESRL 12-flask packages is described. The integrating compressor system uses a mass flow controller to regulate the flow of air through a 15 l volume, thus providing a mixture of air collected over an hour-long period. By beginning with a high flow rate of 3800 standard liters per minute and gradually decreasing the flow rate over time to 290 standard liters per minute it is possible to obtain a nearly uniformly time averaged sample of air and collect it into a pressurized 0.7 l flask. The weighting function determining the air mixture obtained is described in detail. Laboratory and field tests demonstrate that the integrated sample approximates a simple mean of air collected during the one-hour sampling time.

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Turnbull, J., D. Guenther, A. Karion, C. Sweeney, E. Anderson, A. Andrews, J. Kofler, et al. "An integrated flask sample collection system for greenhouse gas measurements." Atmospheric Measurement Techniques 5, no. 9 (September 28, 2012): 2321–27. http://dx.doi.org/10.5194/amt-5-2321-2012.

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Abstract. A one hour integrated flask sampling system to collect air in automated NOAA/ESRL 12-flask packages is described. The integrating compressor system uses a mass flow controller to regulate the flow of air through a 15 l volume, thus providing a mixture of air collected over an hour-long period. By beginning with a high flow rate of 3.8 standard liters per minute and gradually decreasing the flow rate over time to 0.29 standard liters per minute it is possible to obtain a nearly uniformly time averaged sample of air and collect it into a pressurized 0.7 l flask. The weighting function determining the air mixture obtained is described in detail. Laboratory and field tests demonstrate that the integrated sample approximates a simple mean of air collected during the one-hour sampling time.

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Szczurek, Andrzej, and Monika Maciejewska. "Beehive Air Sampling and Sensing Device Operation in Apicultural Applications—Methodological and Technical Aspects." Sensors 21, no. 12 (June 10, 2021): 4019. http://dx.doi.org/10.3390/s21124019.

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The basis of effective beekeeping is the information about the state of the bee colony. A rich source of respective information is beehive air. This source may be explored by applying gas sensing. It allows for classifying bee colony states based on beehive air measurements. In this work, we discussed the essential aspects of beehive air sampling and sensing device operation in apicultural applications. They are the sampling method (diffusive vs. dynamic, temporal aspects), sampling system (sample probe, sampling point selection, sample conditioning unit and sample delivery system) and device operation mode (‘exposure-cleaning’ operation). It was demonstrated how factors associated with the beehive, bee colony and ambient environment define prerequisites for these elements of the measuring instrument. These requirements have to be respected in order to assure high accuracy of measurement and high-quality information. The presented results are primarily based on the field measurement study performed in summer 2020, in three apiaries, in various meteorological conditions. Two exemplars of a prototype gas sensing device were used. These sensor devices were constructed according to our original concept.

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Journal articles on the topic 'Field gas sampling'

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