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Статті в журналах з теми "Field gas sampling":
1
Lawer, Janelle. "Gas sampling for mercury analysis." APPEA Journal 61, no. 2 (2021): 559. http://dx.doi.org/10.1071/aj21013.
Анотація:
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.
2
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.
3
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.
Анотація:
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.
4
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.
Анотація:
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.
5
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.
Анотація:
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.
6
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.
Анотація:
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.
7
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.
Анотація:
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.
8
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.
Анотація:
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.
9
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.
Анотація:
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.
10
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.
Анотація:
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.
Дисертації з теми "Field gas sampling":
1
Murray, Jacolin Ann. "High Flow Air Sampling for Field Detection Using Gas Chromatography-Mass Spectrometry." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2414.
Анотація:
The ability to rapidly detect and identify hazardous analytes in the field has become increasingly important. One of the most important analytical detection methods in the field is gas chromatography-mass spectrometry (GC-MS). In this work, a hand-portable GC-MS system is described that contains a miniature toroidal ion trap mass analyzer and a low thermal mass GC. The system is self-contained within the dimensions of 47 x 36 x 18 cm and weighs less than 13 kg. Because the instrument has a small footprint, it was used as the detector for an automated near-real-time permeation testing system. In permeation testing, materials that are used to make individual protective equipment such as gloves, masks, boots, and suits are exposed to hazardous analytes to determine how long the equipment can be worn safely. The system described herein could test five samples simultaneously. A multi-position valve rotated among the various sample streams and delivered time aliquots into the MS for quantitation. Current field air sampling techniques suffer from long desorption times, high pressure drops, artifact formation and water retention. These disadvantages can be avoided by concentrating the analytes in short open tubular traps containing thick films. There are several advantages to using polymer coated capillaries as traps, including fast desorption, inertness and low flow restriction. An air sampling trap was constructed utilizing open tubular traps for the concentration of semi-volatile organic compounds. The system consisted of multiple capillary traps bundled together, providing high sample flow rates. The analytes were desorbed from the multi-capillary bundle and refocused in a secondary trap. The simultaneous focusing and separation effect of a trap subjected to a negative temperature gradient was also explored. In this configuration, analytes were focused because the front of the peak was at a lower temperature than the rear of the peak and, hence, moved slower. In addition to the focusing effect, analytes with different volatilities focused at different temperatures within the gradient, allowing for separation.
2
Conner, Laura. "Evaluation of field sampling and analysis methods for fire investigation including electronic noses and adsorption sampling/gas chromatography mass spectrometry." FIU Digital Commons, 2005. http://digitalcommons.fiu.edu/etd/2422.
Анотація:
This study evaluates the use of commercially available instruments for locating and collecting accelerants in the field. Electronic noses can be used to scan a fire scene for the possible presence of an accelerant. The TLV Sniffer® was found to be able to detect accelerants at low levels but did alert to some burned matrix alone. When subjected to a proficiency test designed for canines, the TLV Sniffer® was able to locate accelerants in two of the three tests. The tpi®Pocket was found not to be sensitive or selective enough to be useful in locating accelerants. Once the location of possible accelerants has been determined, they can be collected by dynamic headspace sampling in the field with the Portable Arson Sampler (PAS). The PAS was found to be able to collect a broad range of compounds from ignitable liquids and had comparable efficiency to a conventional method.
3
Willett, Evan James. "PREFERENTIAL PATHWAYS FOR VAPOR INTRUSION: SITE SCREENING AND FIELD SAMPLING OF SEWERS TO ASSESS INHALATION EXPOSURE RISKS." UKnowledge, 2018. https://uknowledge.uky.edu/ce_etds/64.
Анотація:
Hazardous waste sites and aging wastewater infrastructure are common in the United States. There are hundreds of thousands of contaminated sites and more than a million miles of sewer pipes. Populations living close to hazardous waste sites often suffer from increased risk of adverse health effects due to exposure to contaminated environmental media. Vapor intrusion is one process by which nearby populations can be exposed to volatile organic compounds (VOCs). Aging wastewater infrastructure is important for vapor intrusion site assessments because sewer pipes can serve as preferential vapor transport pathways. Near contaminated sites, pipe deterioration allows migration of contaminants into sewers and potential accumulation of chemical vapors in sewer gas and nearby buildings. The objectives of this study are to develop a screening-level method to identify contaminated sites where additional evaluation of vapor intrusion is necessary, and then conduct field sampling at these sites to investigate sewers as potential vapor intrusion pathways. Sampling was conducted at four study sites, which consist of former and current dry cleaning facilities located in Lexington, Kentucky. The results of this study demonstrate that preferential vapor intrusion pathways such as sewers can facilitate the spread of vapor intrusion exposure risks beyond source areas of contamination.
4
Parrish, Douglas K. "Application of solid phase microextraction with gas chromatography-mass spectrometry as a rapid, reliable, and safe method for field sampling and analysis of chemical warfare agent precursors /." Download the dissertation in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/Parrish2005.pdf.
5
Lecharlier, Aurore. "Caractérisation des composés trace dans le biogaz et biométhane : développement d'une méthode d'échantillonnage, de préconcentration in situ et d'analyse." Electronic Thesis or Diss., Pau, 2022. http://www.theses.fr/2022PAUU3008.
Анотація:
Afin d’accroître les connaissances sur les composés traces présents dans les biogaz et biométhane et de garantir l’intégration durable de ces gaz dans le mix énergétique européen, une chaîne analytique complète a été développée dont un élément central est un dispositif d’échantillonnage de terrain permettant la préconcentration directe in situ des composés traces en prélevant ces gaz à leur pression actuelle (≤ 200 bara). Les composés traces ciblés dans ce travail incluent : alcanes (linéaires, cycliques, polycycliques), aromatiques, terpènes, alcènes, espèces organiques halogénées, espèces organiques oxygénées (alcools, aldéhydes, esters, éthers, cétones), siloxanes, composés soufrés organiques et inorganiques.L’état de l’art des techniques de prélèvement de gaz et de préconcentration pour la détermination de composés traces dans des matrices gazeuses a premièrement été réalisé. Sur base de cette étude, il fut choisi d’effectuer la préconcentration sur des tubes d’adsorbants multi-lits (TAM) assemblés manuellement. Le système de préconcentration fut élaboré et optimisé au laboratoire en sélectionnant des adsorbants commerciaux; les procédures d’assemblage et de conditionnement des nouveaux TAM furent établies; l’efficacité de quatre configurations de TAM à adsorber et libérer des composés traces ciblés fut testée en utilisant des mélanges de gaz synthétiques certifiés contenant des composés à l’état de traces (1 ppmmol) dans une matrice N2 ou CH4. Les analytes préconcentrés sur les TAM sont récupérés par désorption thermique (DT) des tubes au moyen d’un nouveau prototype de DT pour être analysés par chromatographie en phase gazeuse (CG) couplée à la spectrométrie de masse (SM).Deuxièmement, la méthode analytique et le prototype de DT ont été validés. Il fut démontré que le pouvoir résolutif du prototype de DT était plus élevé que celui obtenu par d’autres techniques de préconcentration ou d’autres méthodes d’injection en CG, telles que la microextraction en phase solide ou l’injection directe de gaz. Par ailleurs, les paramètres de CG-SM furent optimisés pour détecter le large spectre de composés traces potentiellement présents dans le biogaz et biométhane.Troisièmement, un prototype haute-pression innovant fut évalué, permettant le prélèvement de gaz pressurisés (≤ 200 bara) à travers les TAM pour la préconcentration directe et sous haute-pression des composés traces présents dans ces gaz. Ce prototype fut validé au laboratoire au moyen de mélanges de gaz synthétiques pressurisés avant d’être utilisé sur le terrain pour prélever du biométhane à 40 bara au niveau d’un poste d’injection dans le réseau de gaz naturel.Ensuite, la chaîne d’échantillonnage fut assemblée pour mener 6 campagnes de prélèvement durant lesquelles 6 flux différents de biogaz et biométhane furent prélevés sur une installation de stockage de déchets non dangereux et deux sites de méthanisation valorisant divers intrants. Les composés traces de ces gaz furent qualitativement déterminés via la méthode de DT-CG-SM élaborée. En un unique prélèvement et utilisant des volumes de gaz réduits (0.5 – 2 LN), un large spectre de composés traces issus de diverses familles chimiques (alcools, aldéhydes, alcènes, aromatiques, alcanes, esters, éthers, halogénés, cétones, soufrés, siloxanes et terpènes) furent identifiés. Des variations de composition en composés traces furent observées dans les différents gaz et les corrélations potentielles entre intrants, procédés de traitement des gaz et composés traces identifiés, furent discutées. La génération du mono-terpène p-cymène et d’autres terpènes dans les méthaniseurs digérant surtout des résidus alimentaires, a notamment été mise en évidence. La procédure de préconcentration haute-pression in situ développée dans ce travail peut certainement contribuer à faciliter les opérations de prélèvements de gaz sur le terrain pour déterminer les composés traces dans des matrices gazeuses telles que le biogaz et le biométhaneIn pursuance of enhancing knowledge on biogas and biomethane’s trace compounds to help guarantee their sustainable integration in today’s European energy mix, a field sampling set-up enabling direct in situ preconcentration of non-metallic trace compounds in such gas samples at their pipe working pressure (up to 200 bara) was developed. Non-metallic trace compounds targeted in this work included alkanes (linear, cyclic, polycyclic), aromatics, terpenes, alkenes, halogenated organic species, oxygenated organic species (alcohols, aldehydes, esters, furans and ethers, ketones), siloxanes, organic and inorganic Sulphur-compounds. Firstly, state-of-the-art gas sampling and preconcentration techniques for the determination of trace compounds in gaseous matrices were reviewed. Based on this review, preconcentration was chosen to be performed on self-assembled multibed adsorbent tubes (MAT). The preconcentration system was elaborated and optimized in the laboratory: convenient commercial adsorbents were selected; procedures for the assembly and conditioning of new MAT were established; four MAT configurations were tested on their efficiency in adsorbing and releasing targeted trace compounds using certified synthetic gas mixtures containing targeted species at trace concentrations (1 ppmmol) in CH4 or N2 matrices. Analytes preconcentrated on MAT were recovered for analysis by thermal desorption (TD) of the tubes using a new TD prototype followed by gas chromatography (GC) hyphenated with mass spectrometry (MS) (TD-GC-MS). Secondly, the analytical method, and in particular the new TD prototype, was validated. The chromatographic resolution power of the new TD prototype was proved to be higher than that obtained from other well established preconcentration or GC-injection methods such as solid phase microextraction or direct headspace gas injection. Besides, GC-MS parameters were optimized to detect the broad range of trace compounds potentially found in biogas and biomethane.Thirdly, the use of a novel high-pressure tube sampling (HPTS) prototype was evaluated for the circulation of pressurized gases (up to 200 bara) through MAT for the direct high-pressure preconcentration of trace compounds from such gases. The HPTS was first validated in the laboratory using pressurized certified synthetic gas mixtures, and then used on field to sample compressed biomethane at a natural gas grid injection station at 40 bara.Subsequently, the field sampling chain was set-up and 6 field sampling campaigns were conducted where 6 different streams of landfill gas, biogas and biomethane were collected at a landfill plant and two anaerobic digestion plants treating diverse feedstocks. Trace compounds were qualitatively determined in all gas samples via the developed TD-GC-MS method. In a single sampling run and using limited gas volumes ranging 0.5 – 2 LN, a wide range of trace compounds in a variety of chemical families (alcohols, aldehydes, alkenes, aromatics, alkanes (linear, cyclic and polycyclic), esters, furans and ethers, halogenated species, ketones, Sulphur-compounds, siloxanes and terpenes) were identified. Variations in trace compounds composition were observed in the different gases sampled and potential correlations between feedstocks nature, implemented gas treatment processes and trace compounds determined were discussed. In particular, the substantial generation of the mono-terpene p-cymene and of other terpenes was evidenced for anaerobic digestion plants treating principally food-wastes. It is believed the shortened and high-pressure-proof field preconcentration procedure developed in this work can contribute facilitating field sampling operations for the determination of trace compounds in complex gas matrices such as biogas and biomethane
Книги з теми "Field gas sampling":
1
Khosla, Mukul. Increase of the ion-to-gas ratio through an atmospheric pressure sampling orifice using electrostatic field focusing. [Downsview, Ont.]: Institute for Aerospace Studies, University of Toronto, 1992.
2
Khosla, Mukul. Increase of the ion-to-gas ratio through an atmospheric pressure sampling orifice using electrostatic field focusing. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1993.
3
Fox, Raymond. The Use of Self. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780190616144.001.0001.
Анотація:
This monograph presents recent advances in neural network (NN) approaches and applications to chemical reaction dynamics. Topics covered include: (i) the development of ab initio potential-energy surfaces (PES) for complex multichannel systems using modified novelty sampling and feedforward NNs; (ii) methods for sampling the configuration space of critical importance, such as trajectory and novelty sampling methods and gradient fitting methods; (iii) parametrization of interatomic potential functions using a genetic algorithm accelerated with a NN; (iv) parametrization of analytic interatomic potential functions using NNs; (v) self-starting methods for obtaining analytic PES from ab inito electronic structure calculations using direct dynamics; (vi) development of a novel method, namely, combined function derivative approximation (CFDA) for simultaneous fitting of a PES and its corresponding force fields using feedforward neural networks; (vii) development of generalized PES using many-body expansions, NNs, and moiety energy approximations; (viii) NN methods for data analysis, reaction probabilities, and statistical error reduction in chemical reaction dynamics; (ix) accurate prediction of higher-level electronic structure energies (e.g. MP4 or higher) for large databases using NNs, lower-level (Hartree-Fock) energies, and small subsets of the higher-energy database; and finally (x) illustrative examples of NN applications to chemical reaction dynamics of increasing complexity starting from simple near equilibrium structures (vibrational state studies) to more complex non-adiabatic reactions. The monograph is prepared by an interdisciplinary group of researchers working as a team for nearly two decades at Oklahoma State University, Stillwater, OK with expertise in gas phase reaction dynamics; neural networks; various aspects of MD and Monte Carlo (MC) simulations of nanometric cutting, tribology, and material properties at nanoscale; scaling laws from atomistic to continuum; and neural networks applications to chemical reaction dynamics. It is anticipated that this emerging field of NN in chemical reaction dynamics will play an increasingly important role in MD, MC, and quantum mechanical studies in the years to come.
4
Raff, Lionel, Ranga Komanduri, Martin Hagan, and Satish Bukkapatnam. Neural Networks in Chemical Reaction Dynamics. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199765652.001.0001.
Анотація:
This monograph presents recent advances in neural network (NN) approaches and applications to chemical reaction dynamics. Topics covered include: (i) the development of ab initio potential-energy surfaces (PES) for complex multichannel systems using modified novelty sampling and feedforward NNs; (ii) methods for sampling the configuration space of critical importance, such as trajectory and novelty sampling methods and gradient fitting methods; (iii) parametrization of interatomic potential functions using a genetic algorithm accelerated with a NN; (iv) parametrization of analytic interatomic potential functions using NNs; (v) self-starting methods for obtaining analytic PES from ab inito electronic structure calculations using direct dynamics; (vi) development of a novel method, namely, combined function derivative approximation (CFDA) for simultaneous fitting of a PES and its corresponding force fields using feedforward neural networks; (vii) development of generalized PES using many-body expansions, NNs, and moiety energy approximations; (viii) NN methods for data analysis, reaction probabilities, and statistical error reduction in chemical reaction dynamics; (ix) accurate prediction of higher-level electronic structure energies (e.g. MP4 or higher) for large databases using NNs, lower-level (Hartree-Fock) energies, and small subsets of the higher-energy database; and finally (x) illustrative examples of NN applications to chemical reaction dynamics of increasing complexity starting from simple near equilibrium structures (vibrational state studies) to more complex non-adiabatic reactions. The monograph is prepared by an interdisciplinary group of researchers working as a team for nearly two decades at Oklahoma State University, Stillwater, OK with expertise in gas phase reaction dynamics; neural networks; various aspects of MD and Monte Carlo (MC) simulations of nanometric cutting, tribology, and material properties at nanoscale; scaling laws from atomistic to continuum; and neural networks applications to chemical reaction dynamics. It is anticipated that this emerging field of NN in chemical reaction dynamics will play an increasingly important role in MD, MC, and quantum mechanical studies in the years to come.
5
Velkushanova, Konstantina, Linda Strande, Mariska Ronteltap, Thammarat Koottatep, Damir Brdjanovic, and Chris Buckley, eds. Methods for Faecal Sludge Analysis. IWA Publishing, 2021. http://dx.doi.org/10.2166/9781780409122.
Анотація:
Faecal sludge management is recognized globally as an essential component of city-wide inclusive sanitation. However, a major gap in developing appropriate and adequate management and monitoring for faecal sludge is the ability to understand and predict the characteristics and volumes of accumulated faecal sludge, and correlations to source populations. Since standard methods for sampling and analysing faecal sludge do not currently exist, results are not comparable, the actual variability is not yet fully understood, and the transfer of knowledge and data between different regions and institutions can be challenging and often arbitrary. Due to this lack of standard analytical methods for faecal sludge, methods from other fields, such as wastewater management, and soil and food science are frequently applied. However, these methods are not necessarily the most suitable for faecal sludge analysis, and have not been specifically adapted for this purpose. Characteristics of faecal sludge can be different than these other matrices by orders of magnitude. There is also a lack of standard methods for sampling, which is complicated by the difficult nature of in situ sampling, the wide range of onsite sanitation technologies and potential sampling locations, and the diverse heterogeneity of faecal sludge within onsite containments and within cities. This illustrates the urgent need to establish common methods and procedures for faecal sludge characterisation, quantification, sampling, and modelling. The aim of this book is to provide a basis for standardised methods for the analysis of faecal sludge from onsite sanitation technologies, for improved communication between sanitation practitioners, and for greater confidence in the generated data. The book presents background information on types of faecal sludge, methods for sample collection, health and safety procedures for handling, case studies of experimental design, an approach for estimating faecal sludge at community to city-wide scales, modelling containment and treatment processes, recipes for simulants, and laboratory methods for faecal sludge analysis currently in use by faecal sludge laboratories. This book will be beneficial for researchers, laboratory technicians, academics, students and sanitation practitioners. ISBN13: 9781780409115 eISBN: 9781780409122
Частини книг з теми "Field gas sampling":
1
Zhang, Kun, Haibin Song, Jiangxin Chen, Minghui Geng, and Boran Liu. "Gas Seepage Detection and Gas Migration Mechanisms." In South China Sea Seeps, 35–53. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1494-4_3.
Анотація:
AbstractGas seepages are often observed at the seafloor and can form cold seep systems, which are important for climate change, geohazards, and biogeochemical cycles. Many kinds of methods have been used to detect gas seepages, e.g., video imaging, active acoustic, passive acoustic, and direct gas sampling. In this chapter, we introduce the characteristics of these methods and show their applications in the South China Sea (SCS). Particle image velocimetry (PIV) technology is used here to quantitatively detect gas seepage in the northwestern SCS and visualize the seepage flow field. The gas migration mechanisms are also discussed. With the development of technologies, long-term, three-dimensional, and comprehensive observations is permitted to quantitatively characterize gas seepages, which can help us understand the formation and mechanism of gas seepages further in the future. Physical and numerical simulations of gas migration and geohazard processes would also be helpful in the future for understanding the fate of gas seepages.
2
Franklin, Janet, Todd Keeler-Wolf, Kathryn A. Thomas, David A. Shaari, Peter A. Stine, Joel Michaelsen, and Jennifer Miller. "Stratified Sampling for Field Survey of Environmental Gradients in the Mojave Desert Ecoregion." In GIS and Remote Sensing Applications in Biogeography and Ecology, 229–53. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1523-4_14.
3
Penton, Zelda E. "Chapter 10 Headspace gas chromatography." In Sampling and Sample Preparation for Field and Laboratory, 279–96. Elsevier, 2002. http://dx.doi.org/10.1016/s0166-526x(02)80047-2.
4
"Field Techniques for Sampling and Measurement of Soil Gas Constituents at Contaminated Sites." In Remediation Engineering of Contaminated Soils, 669–704. CRC Press, 2000. http://dx.doi.org/10.1201/9781482289930-37.
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"Field Techniques for Sampling and Measurement of Soil Gas Constituents at Contaminated Sites." In Remediation Engineering of Contaminated Soils, 669–704. CRC Press, 2000. http://dx.doi.org/10.1201/9781482289930-37.
6
Schmidt, Steven K., and Ann E. West. "Soil-Atmosphere Gas Exchange." In Structure and Function of an Alpine Ecosystem. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195117288.003.0020.
Анотація:
The alpine, while not extensive in global area, has several advantages for trace gas research, particularly the spatial landscape heterogeneity in soil types and plant communities. This variation can be viewed as a “natural experiment,” allowing field measurements under extremes of moisture and temperature. While the atmospheric carbon dioxide (CO2) record at Niwot Ridge extends back to 1968 (chapter 3), and NOAA has done extensive measurements on atmospheric chemistry at the subalpine climate station (e.g., Conway et al. 1994), work on tundra soil-atmosphere interactions were not initiated until recently. In 1992, studies were begun on Niwot Ridge to gain a comprehensive understanding of trace gas fluxes from alpine soils. Our sampling regime was designed to capture the spatial and temporal patterns of trace gas fluxes in the alpine. In addition, we coupled our studies of trace gas fluxes with ongoing studies of nitrogen cycling on Niwot Ridge (Fisk and Schmidt 1995,1996; Fisk et al. 1998; chapter 12). Methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) were studied because of their role in global environmental change and because they could be easily monitored at our remote sites. On a per-molecule basis, CH4 and N2O are much more potent as greenhouse gases than CO2 is (Lashof and Ahuja 1990; Rodhe 1990). In addition, N2O plays a role in ozone depletion in the stratosphere. The global CH4 and N2O budgets are still poorly understood and the relative importance of soils in these budgets is even less clear. For example, estimates of the global soil sink for CH4 range from 9.0 to 55.9 Tg per year (Dörr et al. 1993). This range is large compared with the approximately 30 Tg of excess CH4 that is accumulating in the atmosphere every year. To better assess the role of soil in trace gas budgets, our work focused on investigating landscape patterns of gas fluxes (CH4, N2O, and CO2) and environmental controls on these fluxes.
7
Lee, P. J. "Estimating Mature Plays." In Statistical Methods for Estimating Petroleum Resources, edited by Jo Anne DeGraffenreid. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195331905.003.0009.
Анотація:
A key objective in petroleum resource evaluation is to estimate oil and gas pool size (or field size) or oil and gas joint probability distributions for a particular population or play. The pool-size distribution, together with the number-of-pools distribution in a play can then be used to predict quantities such as the total remaining potential, the individual pool sizes, and the sizes of the largest undiscovered pools. These resource estimates provide the fundamental information upon which petroleum economic analyses and the planning of exploration strategies can be based. The estimation of these types of pool-size distributions is a difficult task, however, because of the inherent sampling bias associated with exploration data. In many plays, larger pools tend to be discovered during the earlier phases of exploration. In addition, a combination of attributes, such as reservoir depth and distance to transportation center, often influences the order of discovery. Thus exploration data cannot be considered a random sample from the population. As stated by Drew et al. (1988), the form and specific parameters of the parent field-size distribution cannot be inferred with any confidence from the observed distribution. The biased nature of discovery data resulting from selective exploration decision making must be taken into account when making predictions about undiscovered oil and gas resources in a play. If this problem can be overcome, then the estimation of population mean, variance, and correlation among variables can be achieved. The objective of this chapter is to explain the characterization of the discovery process by statistical formulation. To account for sampling bias, Kaufman et al. (1975) and Barouch and Kaufman (1977) used the successive sampling process of the superpopulation probabilistic model (discovery process model) to estimate the mean and variance of a given play. Here we shall discuss how to use superpopulation probabilistic models to estimate pool-size distribution. The models to be discussed include the lognormal (LDSCV), nonparametric (NDSCV), lognormal/nonparametric–Poisson (BDSCV), and the bivariate lognormal, multivariate (MDSCV) discovery process methods. Their background, applications, and limitations will be illustrated by using play data sets from the Western Canada Sedimentary Basin as well as simulated populations.
8
Albastaki, Yousif Abdullatif, and Fatema Albalooshi. "Integrating Smell Sense in Robots Using Artificial Neural Networks." In Electronic Nose Technologies and Advances in Machine Olfaction, 264–73. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-3862-2.ch013.
Анотація:
One of the approaches to mimic the remarkable abilities of the human olfactory system is by the design of computer-controlled sensor arrays that are capable of detecting and distinguishing a different range of smells and odors with consistent monitoring, referred to as electronic noses. This chapter introduces the opportunity of integrating smell sense in robots by the use of artificial neural networks. The study proposes a structure for integrating electronic noses in robots to add the capabilities of smell-related assignments, typically to recognize hazardous substances such as sampling the air and decide its actions based on this information. Utilizing the proposed algorithm allows experts in this field to be aware of gas leakage areas and thus reduce unexpected incidences. The effectiveness of the algorithm is demonstrated using real-world samples, and the performance is examined via quantitative metrics and analysis. The results show that the proposed algorithmic framework outperforms state-of-the-art methods with an error rate of only 0.0999%.
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Olalekan Raimi, Morufu, Henry Olawale Sawyerr, Ifeanyichukwu Clinton Ezekwe, and Salako Gabriel. "Toxicants in Water: Hydrochemical Appraisal of Toxic Metals Concentration and Seasonal Variation in Drinking Water Quality in Oil and Gas Field Area of Rivers State, Nigeria." In Heavy Metals - New Insights [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102656.
Анотація:
Groundwater pollution is a major issue in many tropical countries. Governments at all levels are doing little or nothing to supply inhabitants with clean and accessible water, particularly in Nigeria’s Niger Delta region. This study compares differences in water quality parameters in the study area (determine the level of pollutions in the different sites). The investigation made use of standard analytical methodologies. All sampling, conservation, transportation as well as analysis followed the usual APHA procedures (2012). To prevent degradation of the organic substances, all obtained samples were transferred to the laboratory, while keeping in an icebox. Result shows that during wet season, the mean values obtained for water quality parameters were significantly lower in site 9 compared with that obtained in other sites (p < 0.05) with the exemptions of temperature, DO, BOD, COD, acidity, TH, TDS, K, Mg, Zn, Mn, Cd, Pb, Cu, Cr, NH3, NO2, NO3, Ni though slightly lower in most cases in site 9 were not significantly different (p > 0.05) and both alkalinity and SO4 which were significantly higher in site 9 than site 1 (p < 0.05). Result obtained during dry season reveals that there is no remarkable difference in pH, acidity, Pb and Ni between the nine sites (p > 0.05) while other water quality parameters were significantly lower in site 9 than other sites excluding Cl and Mg which were both significantly higher in site 9 than site 8 (p < 0.05). Extra efforts must be made to completely understand the hydrogeochemical properties and appropriateness of groundwater in Nigeria’s core Niger Delta region in order to ensure quality groundwater supply for varied applications. As a result, this research will contribute to the establishment of a quantitative understanding of the effects of many causes on groundwater level changes in every aquifer worldwide. This analysis also reinforces a useful resource for scholars, activists, and public officials looking to improve community awareness, planning, and performance. The verdicts will serve as a valuable guideline for policymakers, the Ministry of Water Resources, and development practitioners, as they highlight the need for appropriate approaches to mitigating toxic elements of water resource contamination in the core Niger Delta in order to protect public health from carcinogenic and non-carcinogenic risks.
10
Dekorsy, T., X. Q. Zhou, K. Ploog, and H. Kurz. "Subpicosecond electric field dynamics in low-temperature-grown GaAs observed by reflective electro-optic sampling." In European Materials Research Society Symposia Proceedings, 68–71. Elsevier, 1993. http://dx.doi.org/10.1016/b978-0-444-81769-3.50067-x.
Тези доповідей конференцій з теми "Field gas sampling":
1
Jiang, Leiyong, Shaji Manipurath, Gilles Bourque, and Michel Houde. "Flow-Field Investigation of Two Gas-Sampling Probes." In ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-90239.
Анотація:
The flow fields in and around two versions of a water-cooled gas-sampling probe, situated downstream of a gas turbine combustor, were numerically studied in an elevated pressure and temperature environment. The probes are of triple-walled stainless steel assembly, where the gas sample is transported through a centre tube, while preheated and pressurized cooling water flows through two surrounding annuli. Complex conjugate heat transfers amongst the exhaust mixture, cooling water and probe walls were modelled at a selected operating condition. The numerical results indicate over-heating and possible vaporization of water or cavitation in the upstream tip region of the probe with the original design. This is consistent with the evidence of damage observed in these probes from prolonged testing under similar conditions. For the modified probe, the effectiveness of cooling water is much improved, which is confirmed by long-term combustor rig testing. From this investigation, some recommendations for probe design and operation are provided. Moreover, the present study has proved that the numerical simulation is a valuable tool for probe design and trouble-shooting, and to accurately predict conjugate heat transfers in such flows, the laminar sub-layer in the near-wall region should be adequately resolved.
2
Afanasyev, Vitaliy, Bertrand C. Theuveny, Paul Guieze, and Vlamir Bastos. "Sampling with multiphase flowmeter in Northern Siberia - condensate field experience and sensitivities." In SPE Russian Oil and Gas Technical Conference and Exhibition. Society of Petroleum Engineers, 2008. http://dx.doi.org/10.2118/115622-ms.
3
Afanasyev, Vitaliy, Bertrand Theuveny, Sylvain Jayawardane, Alexander Zhandin, Vlamir Bastos, Paul Guieze, Oleg Kulyatin, and Sergey Romashkin. "Sampling With Multiphase Flowmeter in Northern Siberia—Condensate Field Experience and Sensitivities (Russian)." In SPE Russian Oil and Gas Technical Conference and Exhibition. Society of Petroleum Engineers, 2008. http://dx.doi.org/10.2118/115622-ru.
4
Rajkhowa, Anupam, Haifa Al-Bader, Waleed Ahmad Abdel Hameed, Abdul Razzaq Al-Nabhan, and Pakkirisamy Subban. "Challenges on Sampling and Characterization of Heavy Oil in Deep Exploratory Wells: A Field Case Study." In SPE Kuwait Oil and Gas Show and Conference. Society of Petroleum Engineers, 2015. http://dx.doi.org/10.2118/175228-ms.
5
Chin, Alvin Zhi Siang, Cheol Hwan Roh, Fuad Noordin, Zaimi Zainul, Dylan Zhe Xin Ho, Hakim Basri, Ashvin Avalani Chandrakant, et al. "Successful Analysis of Acoustic Sand Monitoring in Tandem with Online Sand Sampling to Safeguard and Optimize Production in a Mature Oil Field." In Gas & Oil Technology Showcase and Conference. SPE, 2023. http://dx.doi.org/10.2118/214128-ms.
Анотація:
Abstract This paper serves to share the findings and best practices of sustaining production for a mature field with high sand production with analysis from Acoustic Sand Monitoring (ASM) paired with Online Sand Sampling (OSS). Field B, located in the East Malaysia Region, is a high oil producer for over 40 years under a strong water drive mechanism. Water production has significantly increased over the past 5 years, which has led to significant sand production impacting surface facilities and well integrity. Hence, the need for a reliable and efficient sand management surveillance in field B. As the first application for oil fields in the region, ASM and OSS was conducted with the objective to determine the maximum sand free production rate from over 80 active strings in Field B over the span of 4 months to safeguard production rates of 10 kbopd. With ASM and OSS, a reduced data surveillance duration can be achieved within 2 hours compared to conventional well sand sampling per well which requires a minimum of 24 hours before sand production rate is determined. ASM sensors are clamped on the well flowline to detect and record the noise vibrations produced by the sand while OSS is conducted concurrently by diverting parts of the same flow from the flowline through a sand filter to have a quantitative representation of sand produced for a predetermined duration. During the campaign, choke sizing was manipulated to control reservoir drawdown. For most wells, a lower drawdown resulted in lower amplitude readings from ASM and less sand observed from OSS. However, there are several wells that had higher sand production at a smaller drawdown due to a change in flow regime (steady flow to intermittent flow) resulted from inefficient gas lift production (multi-pointing). As ASM provided the raw velocity signal which is heavily influenced by the liquid flow regime, gas oil ratio and sand production, OSS results (from physical sand produced and weight of sand particles) established a baseline for ASM signals which indicate a sand free production. Overall, ASM and OSS analysis provided a baseline for determining the optimum rate of production with minimum sand to avoid well integrity issues and protecting the surface facilities, thus allowing continuous field production of 10 kbopd. A presentation and discussion of the successful results, limitations, best practices, and lessons learnt of the ASM and OSS campaign aspires to be additive to the production surveillance sand management in the oil and gas industry by providing a fast and reliable means of identifying optimum sand free production rates for a high number of wells in a mature field.
6
Sajjad, Farasdaq Muchibbus, Steven Chandra, Patrick Ivan, Wingky Suganda, Yudi Budiansah, and Alvin Derry Wirawan. "The Effect of Compositional Gradient in Field Development." In SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205801-ms.
Анотація:
Abstract The existence of fluid’s compositional gradient in a reservoir drives convective flow which brings significant impacts to the operations, e.g., in formulation of injected fluid for well stimulation and enhanced oil Recovery (EOR). However, fluid compositional gradient is not always included in modeling reservoir performance due to PVT sampling limitation and simulation constraint. This work aims to show the significance of compositional convection in oil/gas reservoir and provides our experiences in dealing with this issue in Indonesian’s fields. PHE ONWJ as one of the most prolific producers of oil and gas in Indonesia currently operates an offshore block that has been producing for almost 40 years. Operating in a relatively mature well, PHE ONWJ often encounters significant fluid property change namely oil viscosity and specific gravity that changes overtime as depletion process occur. Data from X field, operated by PHE ONWJ, shows that compositional convection impacts workover and tertiary operations, by deviating from simulation results. We present the evidence of compositional convection using mechanistic models. We firstly adopt field data for setting the initial composition stratification. The stratification is identified through DST or fluid sampling. We secondly perform similarity simulation to analyze the effect of compositional gradient towards oil production. Similarity simulation is performed in the simplified domain for providing generalized solution. This solution is then scaled for the real domain. Finally, we show our approach to encounter the problems. Based on the similarity study inspired by the case of X Field, it shows that the compositional stratification affects geochemistry and near-wellbore flow behavior. The compositional convection develops multiple fluid properties at different depth, which create cross flow among layers. It also causes scale deposition in near wellbore which reduces the permeability and alters rock-fluid interactions, such as wettability and relative permeability. The alteration of near-wellbore geochemistry creates severe flow assurance issues in the wellbore. The mixing of multiple fluids from different layers cause paraffin and scale deposition. In some fields, the mixing triggers severe corrosions which could impact on wellbore integrity. The compositional stratification forces us to develop multiple treatments for different layers in single wellbore. Since the fluid’s properties are different for each layer, the compatibility between injected fluid and reservoir fluids varies.
7
Bodoor, Baroon, David Nelson Jesudian, Basel Al-Otaibi, Hossam Ibrahim, Chen Chao, Viet Le, Ahmed Ghruda, and _. Sofiance. "Comprehensive Study on Ultra-Heavy Oil Deposition in North Kuwait and Successful Fluid Sampling for Field Development Studies: Case Study." In Middle East Oil, Gas and Geosciences Show. SPE, 2023. http://dx.doi.org/10.2118/213242-ms.
Анотація:
Abstract The Burgan reservoir is located in North Kuwait was discovered in 1957. First commercial oil production from this multistack sandstone reservoir started back in 1964. Operating under active bottom water drive as well as edge water drive. The primary reservoir in the field is Burgan of Lower Cretaceous age, which contributes the major oil production of the fields. Burgan reservoir is the second largest reservoir in terms of STOOIP and reserves, producing 30% of daily oil production. Significant amount of historical production came from the lower part of the reservoir where the pattern of water influx is well understood. Most of the historical production and the majority of remaining reserves are in the upper part of the reservoir where the pressure support and water influx are relatively well understood. Presence of tar was initially detected from cores and produced oil in some of the wells and visual inspection of core material. Tar zone in the Burgan was considered to be structurally controlled and occurred in specific depth window around oil-water contact. Heavy oil has been discovered in basal parts of Burgan sandstone in some of the zones within North Kuwait. Development of Burgan in north Kuwait began in the 1950s with oil recovery since then from Burgan channel sands with few exceptions in the North Kuwait as samples confirmed ultra-heavy oil.
8
Ghosh, Arnab, Theodore Klimentos, Rajesh Kumar Singh, Viraj Nangia, Sonia Malik, Krishnendu Ghosh, Shyamal Bhattacharya, and Harish Chadha. "Multi-dimensional NMR Technique for Wireline Formation Tester Sampling Optimization and Perforation Strategy Determination in a Brown Field, India." In SPE Oil and Gas India Conference and Exhibition. Society of Petroleum Engineers, 2012. http://dx.doi.org/10.2118/153657-ms.
9
Ortiz-Volcan, J. L., R. Ghouti, A. M. Al-Naqi, and A. K. Jain. "Heavy Crude Oil Sampling and Assay For Refinery Capacity Planning: Design, Plan and Execution In A Supergiant Green Field." In SPE Kuwait Oil and Gas Show and Conference. Society of Petroleum Engineers, 2015. http://dx.doi.org/10.2118/175292-ms.
10
Azmi, Adif Azral, Nur Ermayani Abu Zar, Raja Azlan Raja Ismail, Nadia Zulkifli, Nikhil Prakash Hardikar, Ivan Y. Nugraha Putra, Jos S. Pragt, Olufemi Adegbola, Fadzilazri Shapiei, and Manh Hung Nguyen. "Bringing the Best of Sampling While Drilling in Highly Deviated S-Profile Wells: Case Studies from a Brown Field, Sabah, Offshore Malaysia." In SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205656-ms.
Анотація:
Abstract Sampling While Drilling has undergone significant changes since its advent early this decade. The continuum of applications has primarily been due to the ability to access highly deviated wellbores, to collect PVT quality and volume of formation fluids. The increased confidence is also a result of numerous applications with varied time-on-wall without ever being stuck. This paper demonstrates the contribution of this technology for reservoir fluid mapping that proved critical to update the resource assessment in a brown field through three infill wells that were a step-out to drill unpenetrated blocks and confirm their isolation from the main block of the field. As a part of the delineation plan, the objective was to confirm the current pressure regime and reservoir fluid type when drilling the S-profile appraisal wells with 75 degrees inclination. Certain sand layers were prone to sanding as evidenced from the field's long production history. Due to the proven record of this technology in such challenges, locally and globally, pipe-conveyed wireline was ruled out. During pre-job planning, there were concerns about sanding, plugging and time-on-wall and stuck tools. Empirical modeling was performed to provide realistic estimates to secure representative fluid samples. The large surface area pad was selected, due to its suitability in highly permeable yet unconsolidated formations. For the first well operation, the cleanup for confirming formation oil began with a cautious approach considering possible sanding. An insurance sample was collected after three hours. For the next target, drawing on the results of the first sampling, the pump rate was increased early in time, and a sample was collected in half the time. Similar steps were followed for the remaining two wells, where water samples were collected. Oil, water, and gas gradients were calculated. Lessons learnt and inputs from Geomechanics were used in aligning the probe face and reference to the critical drawdown pressure (CDP). A total of 4,821 feet (1,469 meters) was drilled. 58 pressures were acquired, with six formation fluid samples and five cleanup cycles for fluid identification purpose. The pad seal efficiency was 95%. The data provided useful insights into the current pressure regime and fault connectivity, enabling timely decisions for well completion. The sampling while drilling deployment was successful in the highly deviated S-profile wells and unconsolidated sand, with no nonproductive time. Because of the continuous circulation, no event of pipe sticking occurred, thereby increasing the confidence, especially in the drilling teams. The sampling while drilling operations were subsequent, due to batch drilling, with minimal time in between the jobs for turning the tools around. The technology used the latest generation sensors, algorithms, computations and was a first in Malaysia. The campaign re-instituted the clear value of information in the given environment and saving cost.
Звіти організацій з теми "Field gas sampling":
1
Simon, James E., Uri M. Peiper, Gaines Miles, A. Hetzroni, Amos Mizrach, and Denys J. Charles. Electronic Sensing of Fruit Ripeness Based on Volatile Gas Emissions. United States Department of Agriculture, October 1994. http://dx.doi.org/10.32747/1994.7568762.bard.
Анотація:
An electronic sensory system for the evaluation of headspace volatiles was developed to determine fruit ripeness and quality. Two prototype systems were designed, constructed, and later modified. The first is an improved version of our original prototype electronic sniffer using a single head sensing unit for use as a single or paired unit placed on an individual fruit surface for applications in the field, lab, or industry. The second electronic sniffer utilizes a matrix of gas sensors, each selected for differential sensitivity to a range of volatile compounds. This system is more sophisticated as it uses multiple gas sensors, but was found to enhance the ability of the sniffer to classify fruit ripeness and quality relative to a single gas sensor. This second sniffer was designed and constructed for the sampling of fresh-cut or whole packs of fruits such as packaged strawberries and blueberries, and can serve as a prototype for research or commercial applications. Results demonstrate that electronic sensing of fruit ripeness based on aromatic volatile gas emissions can be used successfully with fresh frits. Aroma sensing was successful for classifying ripeness in muskmelons, including different cultivars, apples, blueberries, strawberries, and in a complimentary BARD project on tomatoes. This system compared favorably to the physicochemical measurements traditionally employed to assess fruit maturity. This nondestructive sensory system can detect the presence of physically damaged fruits and shows excellent application for use in quality assessment. Electronic sensors of the tin oxide type were evaluated for specificity toward a wide range of volatiles associated with fruit ripeness. Sensors were identified that detected a broad range of alcohols, aldehydes, esters, hydrocarbons, and volatile sulfur compounds, as well as individual volatiles associated with fruit ripening across a wide concentration range. Sensors are not compound specific, thus, the matrix of sensors coupled with discrimination analysis provides a fingerprint to identify the presence of compounds and to assess alterations in fresh products due to alterations in volatile emissions. Engineering developments led to the development of a system to compensate for temperature and relative humidity relative to on-line aroma sensing with melons for ripeness determination and to reduce response time, thus permitting the electronic sniffer to be used for monitoring both fresh and processed food products. The sniffer provides a fast, reliable and nondestructive tool to assess fruit ripeness and quality. We hope that our work will foster the introduction and utilization of this emerging technology into the agricultural and horticultural
2
Ray, Laura, Madeleine Jordan, Steven Arcone, Lynn Kaluzienski, Benjamin Walker, Peter Ortquist Koons, James Lever, and Gordon Hamilton. Velocity field in the McMurdo shear zone from annual ground penetrating radar imaging and crevasse matching. Engineer Research and Development Center (U.S.), December 2021. http://dx.doi.org/10.21079/11681/42623.
Анотація:
The McMurdo shear zone (MSZ) is strip of heavily crevassed ice oriented in the south-north direction and moving northward. Previous airborne surveys revealed a chaotic crevasse structure superimposed on a set of expected crevasse orientations at 45 degrees to the south-north flow (due to shear stress mechanisms). The dynamics that produced this chaotic structure are poorly understood. Our purpose is to present our field methodology and provide field data that will enable validation of models of the MSZ evolution, and here, we present a method for deriving a local velocity field from ground penetrating radar (GPR) data towards that end. Maps of near-surface crevasses were derived from two annual GPR surveys of a 28 km² region of the MSZ using Eulerian sampling. Our robot-towed and GPS navigated GPR enabled a dense survey grid, with transects of the shear zone at 50 m spacing. Each survey comprised multiple crossings of long (> 1 km) crevasses that appear in echelon on the western and eastern boundaries of the shear zone, as well as two or more crossings of shorter crevasses in the more chaotic zone between the western and eastern boundaries. From these maps, we derived a local velocity field based on the year-to-year movement of the same crevasses. Our velocity field varies significantly from fields previously established using remote sensing and provides more detail than one concurrently derived from a 29-station GPS network. Rather than a simple velocity gradient expected for crevasses oriented approximately 45 degrees to flow direction, we find constant velocity contours oriented diagonally across the shear zone with a wavy fine structure. Although our survey is based on near-surface crevasses, similar crevassing found in marine ice at 160 m depth leads us to conclude that this surface velocity field may hold through the body of meteoric and marine ice. Our success with robot-towed GPR with GPS navigation suggests we may greatly increase our survey areas.
3
Wells, Aaron, Tracy Christopherson, Gerald Frost, Matthew Macander, Susan Ives, Robert McNown, and Erin Johnson. Ecological land survey and soils inventory for Katmai National Park and Preserve, 2016–2017. National Park Service, September 2021. http://dx.doi.org/10.36967/nrr-2287466.
Анотація:
This study was conducted to inventory, classify, and map soils and vegetation within the ecosystems of Katmai National Park and Preserve (KATM) using an ecological land survey (ELS) approach. The ecosystem classes identified in the ELS effort were mapped across the park, using an archive of Geo-graphic Information System (GIS) and Remote Sensing (RS) datasets pertaining to land cover, topography, surficial geology, and glacial history. The description and mapping of the landform-vegetation-soil relationships identified in the ELS work provides tools to support the design and implementation of future field- and RS-based studies, facilitates further analysis and contextualization of existing data, and will help inform natural resource management decisions. We collected information on the geomorphic, topographic, hydrologic, pedologic, and vegetation characteristics of ecosystems using a dataset of 724 field plots, of which 407 were sampled by ABR, Inc.—Environmental Research and Services (ABR) staff in 2016–2017, and 317 were from existing, ancillary datasets. ABR field plots were located along transects that were selected using a gradient-direct sampling scheme (Austin and Heligers 1989) to collect data for the range of ecological conditions present within KATM, and to provide the data needed to interpret ecosystem and soils development. The field plot dataset encompassed all of the major environmental gradients and landscape histories present in KATM. Individual state-factors (e.g., soil pH, slope aspect) and other ecosystem components (e.g., geomorphic unit, vegetation species composition and structure) were measured or categorized using standard classification systems developed for Alaska. We described and analyzed the hierarchical relationships among the ecosystem components to classify 92 Plot Ecotypes (local-scale ecosystems) that best partitioned the variation in soils, vegetation, and disturbance properties observed at the field plots. From the 92 Plot Ecotypes, we developed classifications of Map Ecotypes and Disturbance Landscapes that could be mapped across the park. Additionally, using an existing surficial geology map for KATM, we developed a map of Generalized Soil Texture by aggregating similar surficial geology classes into a reduced set of classes representing the predominant soil textures in each. We then intersected the Ecotype map with the General-ized Soil Texture Map in a GIS and aggregated combinations of Map Ecotypes with similar soils to derive and map Soil Landscapes and Soil Great Groups. The classification of Great Groups captures information on the soil as a whole, as opposed to the subgroup classification which focuses on the properties of specific horizons (Soil Survey Staff 1999). Of the 724 plots included in the Ecotype analysis, sufficient soils data for classifying soil subgroups was available for 467 plots. Soils from 8 orders of soil taxonomy were encountered during the field sampling: Alfisols (<1% of the mapped area), Andisols (3%), Entisols (45%), Gelisols (<1%), Histosols (12%), Inceptisols (22%), Mollisols (<1%), and Spodosols (16%). Within these 8 Soil Orders, field plots corresponded to a total of 74 Soil Subgroups, the most common of which were Typic Cryaquents, Typic Cryorthents, Histic Cryaquepts, Vitrandic Cryorthents, and Typic Cryofluvents.
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Pokrzywinski, Kaytee, Kaitlin Volk, Taylor Rycroft, Susie Wood, Tim Davis, and Jim Lazorchak. Aligning research and monitoring priorities for benthic cyanobacteria and cyanotoxins : a workshop summary. Engineer Research and Development Center (U.S.), August 2021. http://dx.doi.org/10.21079/11681/41680.
Анотація:
In 2018, the US Army Engineer Research and Development Center partnered with the US Army Corps of Engineers–Buffalo District, the US Environmental Protection Agency, Bowling Green State University, and the Cawthron Institute to host a workshop focused on benthic and sediment-associated cyanobacteria and cyanotoxins, particularly in the context of harmful algal blooms (HAB). Technical sessions on the ecology of benthic cyanobacteria in lakes and rivers; monitoring of cyanobacteria and cyanotoxins; detection of benthic and sediment-bound cyanotoxins; and the fate, transport, and health risks of cyanobacteria and their associated toxins were presented. Research summaries included the buoyancy and dispersal of benthic freshwater cyanobacteria mats, the fate and quantification of cyanotoxins in lake sediments, and spatial and temporal variation of toxins in streams. In addition, summaries of remote sensing methods, omic techniques, and field sampling techniques were presented. Critical research gaps identified from this workshop include (1) ecology of benthic cyanobacteria, (2) identity, fate, transport, and risk of cyanotoxins produced by benthic cyanobacteria, (3) standardized sampling and analysis protocols, and (4) increased technical cooperation between government, academia, industry, nonprofit organizations, and other stakeholders. Conclusions from this workshop can inform monitoring and management efforts for benthic cyanobacteria and their associated toxins.
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Amirav, Aviv, and Steven Lehotay. Fast Analysis of Pesticide Residues in Agricultural Products. United States Department of Agriculture, November 2002. http://dx.doi.org/10.32747/2002.7695851.bard.
Анотація:
The overall theme of this project was to increase the speed of analysis for monitoring pesticide residues in food. Traditionally, analytical methods for multiple pesticides are time-consuming, expensive, laborious, wasteful, and ineffective to meet critical needs related to food safety. Faster and better methods were needed to provide more cost-effective detection of chemical contaminants, and thus provide a variety of benefits to agriculture. This overarching goal to speed and improve pesticide analysis was successfully accomplished even beyond what was originally proposed by the investigators in 1998. At that time, the main objectives of this project were: 1) to further develop a direct sample introduction (DSI) device that enables fast sampling and introduction of blended-only agricultural products for analysis by gas chromatography (GC); 2) to evaluate, establish, and further develop the method of simultaneous pulsed flame photometric detector (PFPD) and mass spectrometry (MS) detection for enhanced pesticide identification capabilities; and 3) to develop a new and novel MS pesticide analysis method, based on the use of supersonic molecular beams (SMB) for sampling and ionization. The first and third objectives were successfully accomplished as proposed, and the feasibility of the second objective was already demonstrated. The capabilities of the GC/SMB-MS approach alone were so useful for pesticide analysis that the simultaneous use of a PFPD was considered superfluous. Instead, the PFPD was investigated in combination with an electron-capture detector for low-cost, simultaneous analysis of organophosphorus and organochlorine pesticides in fatty foods. Three important, novel research projects not originally described in the proposal were also accomplished: 1) development of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticides in foods; 2) development and optimization of a method using low-pressure (LP) GC/MS to speed pesticide residue analysis; and 3) innovative application of analyte protectants to improve the GC analysis of important problematic pesticides. All of the accomplishments from this project are expected to have strong impact to the analytical community and implications to agriculture and food safety. For one, an automated DSI approach has become commercially available in combination with GC/MS for the analysis of pesticide residues. Meanwhile, the PFPD has become the selective detector of choice for the analysis of organophosphorus pesticides. Great strides were made in SMB-MS through the manufacture of a prototype "Supersonic GC/MS" instrument, which displayed many advantages over commercial GC/MS instruments. Most notably, the QuEChERS method is already being disseminated to routine monitoring labs and has shown great promise to improve pesticide analytical capabilities and increase lab productivity. The implications of these developments to agriculture will be to increase the percentage of food monitored and the scope of residues detected in the food, which will serve to improve food safety. Developed and developing countries alike will be able to use these methods to lower costs and improve results, thus imported/exported food products will have better quality without affecting price or availability. This will help increase trade between nations and mitigate certain disputes over residue levels in imported foods. The improved enforcement of permissible residue levels provided by these methods will have the effect to promote good agricultural practices among previously obstinate farmers who felt no repercussions from illegal or harmful practices. Furthermore, the methods developed can be used in the field to analyze samples quickly and effectively, or to screen for high levels of dangerous chemicals that may intentionally or accidentally appear in the food supply.
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Shamblin, Robert, Kevin Whelan, Mario Londono, and Judd Patterson. South Florida/Caribbean Network early detection protocol for exotic plants: Corridors of invasiveness. National Park Service, July 2022. http://dx.doi.org/10.36967/nrr-2293364.
Анотація:
Exotic plant populations can be potentially catastrophic to the natural communities of South Florida. Aggressive exotics such as Brazillian Pepper (Schinus terebinthifolius) and Melaleuca (Melaleuca quinquinervia) have displaced native habitats and formed monocultures of exotic stands (Dalrymple et al. 2003). Nearby plant nurseries, especially the ones outside the boundaries of Biscayne National Park (BISC) and Everglades National Park (EVER), are a continuous source of new exotic species that may become established within South Florida’s national parks. Early detection and rapid response to these new species of exotic plants is important to maintaining the integrity of the parks’ natural habitats and is a cost-effective approach to management. The South Florida/Caribbean Network (SFCN) developed the South Florida/Caribbean Network Early Detection Protocol for Exotic Plants to target early detection of these potential invaders. Three national parks of South Florida are monitored for invasive, exotic plants using this protocol: Big Cypress National Preserve (BICY), Biscayne National Park (BISC), and Everglades National Park (EVER). These national parks include some 2,411,000 acres (3,767.2 square miles [mi2]) that encompass a variety of habitat types. To monitor the entire area for new species would not be feasible; therefore the basic approach of this protocol is to scan major “corridors of invasiveness,” e.g., paved and unpaved roads, trails, trail heads, off road vehicle (ORV) trails, boat ramps, canals, and campgrounds, for exotic plant species new to the national parks of South Florida. Sampling is optimized using a two- to three-person crew: a trained botanist, a certified herbicide applicator, and optionally a SFCN (or IPMT [Invasive Plant Management Team]) staff member or park staff to take photographs and help with data collection. If infestations are small, they are treated immediately by the herbicide applicator. If large, they are reported to park staff and the Invasive Plant Management Team. The sampling domain is partitioned into five regions, with one region sampled per year. Regions include the terrestrial habitats of Biscayne National Park, the eastern region of Everglades National Park, the western region of Everglades National Park, the northern region of Big Cypress National Preserve, and the southern region of Big Cypress National Preserve. Monitoring of roads, trails, and canals occurs while traveling into and through the parks (i.e., travel at 2–10 mph) using motorized vehicles, airboats, and/or hiking. Campgrounds, boat launches, trailheads, and similar areas, involve complete searches. When an exotic plant is observed, a GPS location is obtained, and coordinates are taken of the plant. Photographs are not taken for every exotic plant encountered, but photographs will be taken for new and unusual species (for example a coastal exotic found in inland habitats). Information recorded at each location includes the species name, size of infestation, abundance, cover class, any treatment/control action taken, and relevant notes. During the surveys, a GPS “track” is also recorded to document the areas surveyed and a field of view is estimated. Field notes, pictures, and GPS data are compiled, entered, and analyzed in a Microsoft Access database. Resource briefs (and optional data summary reports) and associated shapefiles and data are then produced and sent to contacts within the corresponding national parks.
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Wozniakowska, P., D. W. Eaton, C. Deblonde, A. Mort, and O. H. Ardakani. Identification of regional structural corridors in the Montney play using trend surface analysis combined with geophysical imaging, British Columbia and Alberta. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328850.
Анотація:
The Western Canada Sedimentary Basin (WCSB) is a mature oil and gas basin with an extraordinary endowment of publicly accessible data. It contains structural elements of varying age, expressed as folding, faulting, and fracturing, which provide a record of tectonic activity during basin evolution. Knowledge of the structural architecture of the basin is crucial to understand its tectonic evolution; it also provides essential input for a range of geoscientific studies, including hydrogeology, geomechanics, and seismic risk analysis. This study focuses on an area defined by the subsurface extent of the Triassic Montney Formation, a region of the WCSB straddling the border between Alberta and British Columbia, and covering an area of approximately 130,000 km2. In terms of regional structural elements, this area is roughly bisected by the east-west trending Dawson Creek Graben Complex (DCGC), which initially formed in the Late Carboniferous, and is bordered to the southwest by the Late Cretaceous - Paleocene Rocky Mountain thrust and fold belt (TFB). The structural geology of this region has been extensively studied, but structural elements compiled from previous studies exhibit inconsistencies arising from distinct subregions of investigation in previous studies, differences in the interpreted locations of faults, and inconsistent terminology. Moreover, in cases where faults are mapped based on unpublished proprietary data, many existing interpretations suffer from a lack of reproducibility. In this study, publicly accessible data - formation tops derived from well logs, LITHOPROBE seismic profiles and regional potential-field grids, are used to delineate regional structural elements. Where seismic profiles cross key structural features, these features are generally expressed as multi-stranded or en echelon faults and structurally-linked folds, rather than discrete faults. Furthermore, even in areas of relatively tight well control, individual fault structures cannot be discerned in a robust manner, because the spatial sampling is insufficient to resolve fault strands. We have therefore adopted a structural-corridor approach, where structural corridors are defined as laterally continuous trends, identified using geological trend surface analysis supported by geophysical data, that contain co-genetic faults and folds. Such structural trends have been documented in laboratory models of basement-involved faults and some types of structural corridors have been described as flower structures. The distinction between discrete faults and structural corridors is particularly important for induced seismicity risk analysis, as the hazard posed by a single large structure differs from the hazard presented by a corridor of smaller pre-existing faults. We have implemented a workflow that uses trend surface analysis based on formation tops, with extensive quality control, combined with validation using available geophysical data. Seven formations are considered, from the Late Cretaceous Basal Fish Scale Zone (BFSZ) to the Wabamun Group. This approach helped to resolve the problem of limited spatial extent of available seismic data and provided a broader spatial coverage, enabling the investigation of structural trends throughout the entirety of the Montney play. In total, we identified 34 major structural corridors and number of smaller-scale structures, for which a GIS shapefile is included as a digital supplement to facilitate use of these features in other studies. Our study also outlines two buried regional foreland lobes of the Rocky Mountain TFB, both north and south of the DCGC.
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Anderson, Gerald L., and Kalman Peleg. Precision Cropping by Remotely Sensed Prorotype Plots and Calibration in the Complex Domain. United States Department of Agriculture, December 2002. http://dx.doi.org/10.32747/2002.7585193.bard.
Анотація:
This research report describes a methodology whereby multi-spectral and hyperspectral imagery from remote sensing, is used for deriving predicted field maps of selected plant growth attributes which are required for precision cropping. A major task in precision cropping is to establish areas of the field that differ from the rest of the field and share a common characteristic. Yield distribution f maps can be prepared by yield monitors, which are available for some harvester types. Other field attributes of interest in precision cropping, e.g. soil properties, leaf Nitrate, biomass etc. are obtained by manual sampling of the filed in a grid pattern. Maps of various field attributes are then prepared from these samples by the "Inverse Distance" interpolation method or by Kriging. An improved interpolation method was developed which is based on minimizing the overall curvature of the resulting map. Such maps are the ground truth reference, used for training the algorithm that generates the predicted field maps from remote sensing imagery. Both the reference and the predicted maps are stratified into "Prototype Plots", e.g. 15xl5 blocks of 2m pixels whereby the block size is 30x30m. This averaging reduces the datasets to manageable size and significantly improves the typically poor repeatability of remote sensing imaging systems. In the first two years of the project we used the Normalized Difference Vegetation Index (NDVI), for generating predicted yield maps of sugar beets and com. The NDVI was computed from image cubes of three spectral bands, generated by an optically filtered three camera video imaging system. A two dimensional FFT based regression model Y=f(X), was used wherein Y was the reference map and X=NDVI was the predictor. The FFT regression method applies the "Wavelet Based", "Pixel Block" and "Image Rotation" transforms to the reference and remote images, prior to the Fast - Fourier Transform (FFT) Regression method with the "Phase Lock" option. A complex domain based map Yfft is derived by least squares minimization between the amplitude matrices of X and Y, via the 2D FFT. For one time predictions, the phase matrix of Y is combined with the amplitude matrix ofYfft, whereby an improved predicted map Yplock is formed. Usually, the residuals of Y plock versus Y are about half of the values of Yfft versus Y. For long term predictions, the phase matrix of a "field mask" is combined with the amplitude matrices of the reference image Y and the predicted image Yfft. The field mask is a binary image of a pre-selected region of interest in X and Y. The resultant maps Ypref and Ypred aremodified versions of Y and Yfft respectively. The residuals of Ypred versus Ypref are even lower than the residuals of Yplock versus Y. The maps, Ypref and Ypred represent a close consensus of two independent imaging methods which "view" the same target. In the last two years of the project our remote sensing capability was expanded by addition of a CASI II airborne hyperspectral imaging system and an ASD hyperspectral radiometer. Unfortunately, the cross-noice and poor repeatability problem we had in multi-spectral imaging was exasperated in hyperspectral imaging. We have been able to overcome this problem by over-flying each field twice in rapid succession and developing the Repeatability Index (RI). The RI quantifies the repeatability of each spectral band in the hyperspectral image cube. Thereby, it is possible to select the bands of higher repeatability for inclusion in the prediction model while bands of low repeatability are excluded. Further segregation of high and low repeatability bands takes place in the prediction model algorithm, which is based on a combination of a "Genetic Algorithm" and Partial Least Squares", (PLS-GA). In summary, modus operandi was developed, for deriving important plant growth attribute maps (yield, leaf nitrate, biomass and sugar percent in beets), from remote sensing imagery, with sufficient accuracy for precision cropping applications. This achievement is remarkable, given the inherently high cross-noice between the reference and remote imagery as well as the highly non-repeatable nature of remote sensing systems. The above methodologies may be readily adopted by commercial companies, which specialize in proving remotely sensed data to farmers.
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Taverna, Kristin. Vegetation classification and mapping of land additions at Richmond National Battlefield Park, Virginia: Addendum to technical report NPS/NER/NRTR 2008/128. National Park Service, September 2022. http://dx.doi.org/10.36967/2294278.
Анотація:
In 2008 and 2015, the Virginia Department of Conservation and Recreation, Division of Natural Heritage produced vegetation maps for Richmond National Battlefield Park, following the protocols of the United States Geological Survey (USGS) – National Park Service (NPS) Vegetation Mapping Program. The original 2008 report was part of a regional project to map and classify the vegetation in seven national parks in Virginia. The 2015 report was an addendum to the original report and mapped the vegetation in newly acquired parcels. Since 2015, the park has acquired an additional 820 acres of land within 12 individual parcels, including the 650 acre North Anna unit. This report is an addendum to the 2008 and 2015 reports and documents the mapping of vegetation and other land-use classes for the 12 new land parcels at Richmond National Battlefield Park, with an updated vegetation map for the entire park. The updated map and associated data provide information on the sensitivity and ecological integrity of habitats and can help prioritize areas for protection. The vegetation map of the new land parcels includes eighteen map classes, representing 14 associations from the United States National Vegetation Classification, one nonstandard, park-specific class, and three Anderson Level II land-use categories. The vegetation classification and map classes are consistent with the original 2008 report. Vegetation-map classes for the new land parcels were identified through field reconnaissance, data collection, and aerial photo interpretation. Aerial photography from 2017 served as the base map for mapping the 12 new parcels, and field sampling was conducted in the summer of 2020. Three new map classes for the Park were encountered and described during the study, all within the North Anna park unit. These map classes are Coastal Plain / Outer Piedmont Basic Mesic Forest, Northern Coastal Plain / Piedmont Oak – Beech / Heath Forest, and Southern Piedmont / Inner Coastal Plain Floodplain Terrace Forest. The examples of Coastal Plain / Outer Piedmont Basic Mesic Forest and Southern Piedmont / Inner Coastal Plain Floodplain Terrace Forest at North Anna meet the criteria of size, condition, and landscape context to be considered a Natural Heritage exemplary natural community occurrence and should be targeted for protection and management as needed. New local and global descriptions for the three map classes are included as part of this report. Refinements were made to the vegetation field key to include the new map classes. The updated field key is part of this report. An updated table listing the number of polygons and total hectares for each of the 28 vegetation- map classes over the entire park is also included in the report. A GIS coverage containing a vegetation map for the entire park with updated Federal Geographic Data Committee (FGDC) compliant metadata was completed for this project. The attribute table field names are the same as the 2008 and 2015 products, with the exception of an additional field indicating the year each polygon was last edited.
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Evans, Julie, Kendra Sikes, and Jamie Ratchford. Vegetation classification at Lake Mead National Recreation Area, Mojave National Preserve, Castle Mountains National Monument, and Death Valley National Park: Final report (Revised with Cost Estimate). National Park Service, October 2020. http://dx.doi.org/10.36967/nrr-2279201.
Анотація:
Vegetation inventory and mapping is a process to document the composition, distribution and abundance of vegetation types across the landscape. The National Park Service’s (NPS) Inventory and Monitoring (I&M) program has determined vegetation inventory and mapping to be an important resource for parks; it is one of 12 baseline inventories of natural resources to be completed for all 270 national parks within the NPS I&M program. The Mojave Desert Network Inventory & Monitoring (MOJN I&M) began its process of vegetation inventory in 2009 for four park units as follows: Lake Mead National Recreation Area (LAKE), Mojave National Preserve (MOJA), Castle Mountains National Monument (CAMO), and Death Valley National Park (DEVA). Mapping is a multi-step and multi-year process involving skills and interactions of several parties, including NPS, with a field ecology team, a classification team, and a mapping team. This process allows for compiling existing vegetation data, collecting new data to fill in gaps, and analyzing the data to develop a classification that then informs the mapping. The final products of this process include a vegetation classification, ecological descriptions and field keys of the vegetation types, and geospatial vegetation maps based on the classification. In this report, we present the narrative and results of the sampling and classification effort. In three other associated reports (Evens et al. 2020a, 2020b, 2020c) are the ecological descriptions and field keys. The resulting products of the vegetation mapping efforts are, or will be, presented in separate reports: mapping at LAKE was completed in 2016, mapping at MOJA and CAMO will be completed in 2020, and mapping at DEVA will occur in 2021. The California Native Plant Society (CNPS) and NatureServe, the classification team, have completed the vegetation classification for these four park units, with field keys and descriptions of the vegetation types developed at the alliance level per the U.S. National Vegetation Classification (USNVC). We have compiled approximately 9,000 existing and new vegetation data records into digital databases in Microsoft Access. The resulting classification and descriptions include approximately 105 alliances and landform types, and over 240 associations. CNPS also has assisted the mapping teams during map reconnaissance visits, follow-up on interpreting vegetation patterns, and general support for the geospatial vegetation maps being produced. A variety of alliances and associations occur in the four park units. Per park, the classification represents approximately 50 alliances at LAKE, 65 at MOJA and CAMO, and 85 at DEVA. Several riparian alliances or associations that are somewhat rare (ranked globally as G3) include shrublands of Pluchea sericea, meadow associations with Distichlis spicata and Juncus cooperi, and woodland associations of Salix laevigata and Prosopis pubescens along playas, streams, and springs. Other rare to somewhat rare types (G2 to G3) include shrubland stands with Eriogonum heermannii, Buddleja utahensis, Mortonia utahensis, and Salvia funerea on rocky calcareous slopes that occur sporadically in LAKE to MOJA and DEVA. Types that are globally rare (G1) include the associations of Swallenia alexandrae on sand dunes and Hecastocleis shockleyi on rocky calcareous slopes in DEVA. Two USNVC vegetation groups hold the highest number of alliances: 1) Warm Semi-Desert Shrub & Herb Dry Wash & Colluvial Slope Group (G541) has nine alliances, and 2) Mojave Mid-Elevation Mixed Desert Scrub Group (G296) has thirteen alliances. These two groups contribute significantly to the diversity of vegetation along alluvial washes and mid-elevation transition zones.