Academic literature on the topic 'Ion chemistry and composition'
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Journal articles on the topic "Ion chemistry and composition"
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Ip, W. H. "Ion composition and chemistry." Advances in Space Research 9, no. 3 (1989): 141–50. http://dx.doi.org/10.1016/0273-1177(89)90253-6.
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Breig, E. L. "Thermospheric ion and neutral composition and chemistry." Reviews of Geophysics 25, no. 3 (1987): 455. http://dx.doi.org/10.1029/rg025i003p00455.
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Vuitton, V., R. V. Yelle, and P. Lavvas. "Composition and chemistry of Titan's thermosphere and ionosphere." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367, no. 1889 (2008): 729–41. http://dx.doi.org/10.1098/rsta.2008.0233.
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Titan has long been known to harbour the richest atmospheric chemistry in the Solar System. Until recently, it had been believed that complex hydrocarbons and nitriles were produced through neutral chemistry that would eventually lead to the formation of micrometre sized organic aerosols. However, recent measurements by the Cassini spacecraft are drastically changing our understanding of Titan's chemistry. The Ion and Neutral Mass Spectrometer (INMS) and the Cassini Plasma Spectrometer (CAPS) revealed an extraordinary complex ionospheric composition. INMS detected roughly 50 positive ions with m / z <100 and a density higher than 0.1 cm −3 . CAPS provided evidence for heavy (up to 350 amu) positively and negatively charged (up to 4000 amu) ions. These observations all indicate that Titan's ionospheric chemistry is incredibly complex and that molecular growth starts in the upper atmosphere rather than at lower altitude. Here, we review the recent progress made on ionospheric chemistry. The presence of heavy neutrals in the upper atmosphere has been inferred as a direct consequence of the presence of complex positive ions. Benzene (C 6 H 6 ) is created by ion chemistry at high altitudes and its main photolysis product, the phenyl radical (C 6 H 5 ), is at the origin of the formation of aromatic species at lower altitude.
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Johnston, Kathryn A., Lisa M. Stabryla, Ashley M. Smith, Xing Yee Gan, Leanne M. Gilbertson, and Jill E. Millstone. "Impacts of broth chemistry on silver ion release, surface chemistry composition, and bacterial cytotoxicity of silver nanoparticles." Environmental Science: Nano 5, no. 2 (2018): 304–12. http://dx.doi.org/10.1039/c7en00974g.
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We determine the impact of bacterial growth media on silver nanoparticle surface chemistry, this surface chemistry on silver ion release from the nanoparticles, and ultimately the antimicrobial implications of those parameters.
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Feistel, Rainer. "On the Physical Chemistry of Seawater with Deviating Ion Composition." Zeitschrift für Physikalische Chemie 204, Part_1_2 (1998): 27–44. http://dx.doi.org/10.1524/zpch.1998.204.part_1_2.027.
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Kishor, Arora, C. Goyal R., D. Agarwal D. та C. Pathak M. "Synthesis and spectral studies of thorium( IV) and dioxouranium(V) metal complexes with Schiff base ligandΨ". Journal of Indian Chemical Society Vol. 79, Aug 2002 (2002): 686–88. https://doi.org/10.5281/zenodo.5843399.
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Department of Chemistry, Government Autonomous K. R. G. College, Gwalior-474 001, India <em>E-mail : </em>kishorarora@rediffmail.com Department of Chemistry, Government P. G. College, Morena-476 001, India School of Studies in Chemistry, Jiwaji University, Gwalior-474 011, India Department of Chemistry, Government Autonomous Science College, Gwalior, India <em>Manuscript received 9 August 2001, revised 9 January 2002, accepted 5 April 2002</em> A series of new complexes of Schiff base 2-bromo-1<em>N</em>[4-N,N-bis(2'-cynoethylaminobenzalidene)Jaminobenzene (BCABAB) have been prepared from thorium(IV) and dioxouranium(V) metal salts having composition UO<sub>2</sub>X<sub>2</sub>.<em>n</em>L (X = CH<sub>3</sub>COO<sup>-</sup>, NO<sup>-3</sup>, I<sup>-</sup> or NCS<sup>-</sup>, <em>n </em>= 2; X = ClO<sup>-4</sup>; L = BCABAB) and ThX<sub>4</sub>.nL (X = NO<sup>-</sup><sub>3</sub>, NCS<sup>-</sup>, <em>n</em> = 2, X = I<sup>-</sup><em> </em>= 4 and X = ClO<sup>-</sup><sub>4</sub>; n = 6, L = BCABAB). BCABAB acts as neutral monodentate ligand and coordinate to the metal ion via azomethine nitrogen.
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Vigren, Erik. "Analytic model of comet ionosphere chemistry." Astronomy & Astrophysics 616 (August 2018): A59. http://dx.doi.org/10.1051/0004-6361/201832704.
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Context. We consider a weakly to moderately active comet and make the following simplifying assumptions: (i) The partial ionization frequencies are constant throughout the considered part of the coma. (ii) All species move radially outward with the same constant speed. (iii) Ion-neutral reactions affect the chemical composition of the ions, but ion removal through dissociative recombination with free electrons is negligible. Aims. We aim to derive an analytical model for the radial variation of the abundances of various cometary ions. Methods. We present two methods for retrieving the ion composition as a function of r. The first method, which has previously been used frequently, solves a series of coupled differential equations. The new method introduced here is based on probabilistic arguments and is analytical in nature. Results. For a pure H2O coma, the resulting closed-form expressions yield results that are identical to the standard method, but are computationally much less expensive. Conclusions. In addition to the computational simplicity, the analytical model provides insight into how the various abundances depend on parameters such as comet production rate, outflow speed, and reaction rate coefficients. It can also be used to investigate limiting cases. It cannot easily be extended to account for a radially varying flow speed or dissociative recombination in the way a code based on numerical integrations can.
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Litvin, A., W. Kofman, and B. Cabrit. "Ion composition measurements and modelling at altitudes from 140 to 350 km using EISCAT measurements." Annales Geophysicae 16, no. 10 (1998): 1159–68. http://dx.doi.org/10.1007/s00585-998-1159-6.
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Abstract. This work aims at processing the data of CP1 and CP2 programs of EISCAT ionospheric radar from 1987 to 1994 using the "full profile" method which allows to solve the "temperature-composition" ambiguity problem in the lower F region. The program of data analysis was developed in the CEPHAG in 1995–1996. To improve this program, we implemented another analytical function to model the ion composition profile. This new function better reflects the real profile of the composition. Secondly, we chose the best method to select the initial conditions for the "full profile" procedure. A statistical analysis of the results was made to obtain the averages of various parameters: electron concentration and temperature, ion temperature, composition and bulk velocity. The aim is to obtain models of the parameter behaviour defining the ion composition profiles : z50 (transition altitude between atomic and molecular ions) and dz (width of the profile), for various seasons and for high and low solar activities. These models are then compared to other models. To explain the principal features of parameters z50 and dz, we made an analysis of the processes leading to composition changes and related them to production and electron density profile. A new experimental model of ion composition is now available.Key words. Auroral ionosphere · Ion chemistry and composition · Instruments and techniques · EISCAT
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Verronen, P. T., E. Turunen, Th Ulich, and E. Kyrölä. "Modelling the effects of the October 1989 solar proton event on mesospheric odd nitrogen using a detailed ion and neutral chemistry model." Annales Geophysicae 20, no. 12 (2002): 1967–76. http://dx.doi.org/10.5194/angeo-20-1967-2002.
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Abstract. Solar proton events and electron precipitation affect the concentrations of middle atmospheric constituents. Ionization caused by precipitating particles enhances the production of important minor neutral constituents, such as nitric oxide, through reaction chains in which ionic reactions play an important role. The Sodankylä Ion Chemistry model (SIC) has been modified and extended into a detailed ion and neutral chemistry model of the mesosphere. Our steady-state model (containing 55 ion species, 8 neutral species, and several hundred chemical reactions) is used to investigate the effect of the October 1989 solar proton event on odd nitrogen at altitudes between 50–90 km. The modelling results show that the NO concentration is significantly enhanced due to the proton precipitation, reaching 107 –108 cm-3 throughout the mesosphere on the 20 October when the proton forcing was most severe. A comparison between the chemical production channels of odd nitrogen indicates that ion chemical reactions are an important factor in the total odd nitrogen production during intense ionization. The modelled electron concentration for the 23 October is compared with EISCAT incoherent scatter radar measurements and a reasonable agreement is found.Key words. Atmospheric composition and structure (Middle atmosphere – composition and chemistry); Ionosphere (Particle precipitation)
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Yutkin, M. P., C. J. Radke, and T. W. Patzek. "Chemical Compositions in Salinity Waterflooding of Carbonate Reservoirs: Theory." Transport in Porous Media 136, no. 2 (2021): 411–29. http://dx.doi.org/10.1007/s11242-020-01517-7.
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AbstractHigher oil recovery after waterflood in carbonate reservoirs is attributed to increasing water wettability of the rock that in turn relies on complicated surface chemistry. In addition, calcite mineral reacts with aqueous solutions and can alter substantially the composition of injected water by mineral dissolution. Carefully designed chemical and/or brine flood compositions in the laboratory may not remain intact while the injected solutions pass through the reactive reservoir rock. This is especially true for a low-salinity waterflood process, where some finely tuned brine compositions can improve flood performances, whereas others cannot. We present a 1D reactive transport numerical model that captures the changes in injected compositions during water flow through porous carbonate rock. We include highly coupled bulk aqueous and surface carbonate-reaction chemistry, detailed reaction and mass transfer kinetics, 2:1 calcium ion exchange, and axial dispersion. At typical calcite reaction rates, local equilibrium is established immediately upon injection. In SI, we validate the reactive transport model against analytic solutions for rock dissolution, ion exchange, and longitudinal dispersion, each considered separately. Accordingly, using an open-source algorithm (Charlton and Parkhurst in Comput Geosci 37(10):1653–1663, 2011. 10.1016/j.cageo.2011.02.005), we outline a design tool to specify chemical/brine flooding formulations that correct for composition alteration by the carbonate rock. Subsequent works compare proposed theory against experiments on core plugs of Indiana limestone and give examples of how injected salinity compositions deviate from those designed in the laboratory for water-wettability improvement.
Dissertations / Theses on the topic "Ion chemistry and composition"
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Wronska, Louisa Victoria May. "The factors & protocols that influence accuracy, precision & uncertainty of accurate mass measurements by Fourier transform ion cyclotron resonance mass spectrometry to validate the assignment of elemental composition." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/67059/.
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The need for very accurate mass measurements of compounds is becoming more demanding with the expansion of the number of compounds in need of correct identification and with the limits of elemental analysis; a fast, robust analytical solution is sought. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is a very powerful tool for undertaking accurate mass measurements because of its high resolving power and mass accuracy. The use of FT-ICR MS in a high-throughput environment is limited due to the need of operator intervention required to obtain optimum accurate mass measurements. The lowest mass measurement errors (MME) are usually obtained using internal calibration, as the sample and calibrant ions inside the ICR cell experience the same conditions. However, internal calibration requires calibrant ions to be selected according to the mass of the sample ion, which requires operator intervention. External calibration is the preferred choice when performing accurate mass measurements in a high-throughput environment, as a calibration can be acquired independently of the sample. This study aims to demonstrate the use of ion population balancing using a dual sprayer approach to reduce MME. Population balancing between sample ions and calibrant ions can reduce the MME 40-fold. Ion populations across a chromatographic run can also vary greatly. The dual sprayer can also be employed to easily control the ion populations of both sample and calibrant entering the cell and can help to reduce ion suppression. The aim of the latter part of the work was to address the uncertainty of an accurate mass measurement performed using FT-ICR MS. In order to confidently select an elemental formula following an accurate mass measurement, a ‘cut-off’ limit or tolerance has to be selected. This tolerance can be set by calculating the uncertainty of the measurement; without an uncertainty component the measurement is meaningless. The work herein demonstrates how to calculate uncertainty of an accurate mass measurement with the aim that journals will adopt a procedure of only accepting an accurate mass measurement which quotes an uncertainty.
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Martin, Riana Theresa. "Evaluation of capillary electrophoresis as an analytical technique using bulk ionic composition of fluid inclusions in quartz." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51751.
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Thesis (MSc)--Stellenbosch University, 2000.<br>ENGLISH ABSTRACT: This study was initialized to introduce capillary electrophoresis (CE) as a useful technique in
the analysis of fluid inclusions in quartz. lts advantages are low detection limits for the
dissolved ionic content of the fluid, the small amount of sample (1 g or less) for a detailed
qualitative and quantitative analysis, and the short time required to obtain results (one run for
either cations or anions take approximately 10 minutes).
The study area from which quartz veins were selected is situated within the Neoproterozoic
Saldania belt. Syn- and post-tectonic S-, 1- and A-type granitoids from the Cape Granite Suite
intruded the metamorphosed Malmesbury greywacke and pelites between 550 and 510 Ma.
Additional periods of tectonism and metamorphism occurred during Cape Supergroup
sedimentation (480 - 400 Ma) as well as Karoo sedimentation and the simultaneous Cape
Orogeny (280 -215 Ma).
The quartz-biotite±chlorite vems are hosted by Cape Granite as well as Malmesbury
sediments. These barren quartz veins are part of two vein sets, one dipping at an angle
between 15 and 500 to the S to SE and striking W, similar to Sn-mineralized quartz veins in
the SW-cape, while the other is near-vertical and striking W to NW. Except for their
orientation, no differences regarding associated minerals, inclusion characteristics or fluid
chemistry indicated a difference in origin.
Four fluid phases within a temperature range of 160 - 390 °C were identified as being largely
late-magmatic and released from the underlying Cape Granite plutons, namely an early 370-
390 °C population, followed by the 310 - 360, 230 - 300 and lastly the 160 - 200 °C
populations. Initiation of this fluid system occurred from at least SlOMa, after final granite
intrusion, but the age of the final stage is unknown. Renewed fluid circulation occurred during a later period of metamorphism, possibly during the Cape Orogeny. These fluids had
temperatures between 240 and 360°C and are of sedimentary origin, most likely released
from the Malmesbury metamorphites.
The technique of capillary electrophoresis has been evaluated for its application to bulk fluid
inclusion analysis, and the crush-leach fluid extraction procedure of Bottrell, et al., (1988)
optimized for CE analysis. Contamination factors were identified and minimized or
eliminated, where possible. Bulk fluid inclusion chemistry obtained by CE was therefore
proved to provide valuable information regarding the various fluid generations as long as
inclusion populations are investigated individually to explain and correlate bulk data.<br>AFRIKAANSE OPSOMMING: Die doel van die studie was om te toon dat die tegniek van kapillêre elektroforese bruikbaar is
in die analiese van vloeistofmsluitsels in kwarts. Die voordele van hierdie tegniek is lae
deteksie limiete vir die opgeloste ioon inhoud van die vloeistof, die klein monstergrootte
(< 1g) wat nodig is vir 'n omvattende kwalitatiewe en kwantitatiewe analise, en die kort
tydsduur waarin resultate verkry word ('n katioon of anioon analise vir een monster duur lO
minute).
Die studie gebied waar kwarts are gemonster is, is binne die Neoproterosoïese Saldania
Gordel geleë. Sin- en laat-tektoniese S-, I- en A-tipe graniete van die Kaapse Graniet Suite het
die gemetamorfiseerde Malmesbury grouwakke en peliete tussen 550 en 510 Ma
binnegedring. Latere periodes van tektonisme en metamorfose het tydens deponering van die
Kaap Supergroep (480 - 400 Ma), en die gelyktydige episodes van Karoo sedimentasie en
Kaapse Orogenese (280 - 215 Ma) plaasgevind.
Die gasheer gesteentes vir die kwarts-biotiet±chloriet are is Kaapse Graniet sowel as
Malmesbury sedimente. Hierdie ongemineraliseerde are is deel van twee aarstelsels, nl. een
met 'n duik hoek tussen 15 en 50° S tot SO en 'n westelike strekking, soortgelyk aan die Sn-
,.gemineraliseerde are in die SW-Kaap, terwyl die ander stel are feitlik vertikaal is en W tot
NW strek. Behalwe vir die verskil in oriëntasie was daar geen aanduiding, wat betref 'n
verskil in geassosieerde minerale, vloeistofinsluitsel kenmerke of vloeistof chemie, dat hierdie
twee aarstelsels van verskillende oorsprong is nie.
Vier vloeistof fases binne 'n temperatuur gebied van 160 - 390 °C en 'n vloeistof saliniteit
van 0 - 5.7 gewig % NaC1 ekw. is geïdentifiseer, met 'n laat-magmatiese assosiasie en
vrygestel deur die onderliggende Kaapse Graniete. Dit behels 'n vroeë 370 - 390 °C populasie, gevolg deur die 310 - 360, 230 - 300 en laastens die 160 - 200 °C populasies.
Inisiasie van hierdie sisteem kon moontlik rondom 510 Ma gelede plaasgevind het, maar die
ouderdom van die finale fase is onbekend. Hernude vloeistof sirkulasie het tydens 'n later
stadium van metamorfose onstaan, moontlik tydens die Kaapse Orogenese. Hierdie
vloeistowwe het temperature tussen 240 en 360 °C en is van sedimentêre oorsprong waar dit
moontlik deur metamorfose van die reeds gemetamorfiseerde Malmesbury gesteentes
vrygestel is.
Die tegniek van kapillêre elektroforese is vir die toepassing daarvan in die analise van
vloeistof insluitsels in kwarts geëvalueer, terwyl die vloeistof vrystellingsmetode van Bottrell
en Yardley (1988) vir hierdie tegniek geoptimaliseer is. Kontaminasie faktore is geïdentifiseer
en verminder of uitgeskakel waar moontlik. Daar is getoon dat die vloeistof chemie, wat
verteenwoordigend is van al die insluitsel populasies in 'n monster, wel bruikbaar is t.o.v.
afsonderlike vloeistof generasies, solank elke populasie individueel bestudeer is om die
omvattende chemiese data te verduidelik en met 'n enkele populasie te korrelleer.
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Toida, Mieko, Hiroyuki Higashino, and Yukiharu Ohsawa. "Effect of ion composition on ion acceleration by magnetosonic shock waves." American Institite of Physics, 2008. http://hdl.handle.net/2237/12029.
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Isildak, Ibrahim. "Ion selective electrodes in ion chromatography." Thesis, University of Newcastle Upon Tyne, 1992. http://hdl.handle.net/10443/859.
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The number of applications of potentiometric detection In Ion chromatography Is Increasing In the use of ion selective electrodes for which the response Is not limited to a few number of Ions. In this research, membrane electrodes, for a number of Ions, based on PVC were prepared to examine selectivity, detection limit and reproducibility for chromatographic and flow-injection measurements via mixed solution method and flow-injection technique. The selectivity sequence of anion selective electrodes for single charged Inorganic anions was F< Cl < Br < NO 2< NO 3<I. This was Ll +< Nil+< Cs+< Na+< K+ for cation selective electrodes. The 4 detection limits for most of anions and cations were found to be at the nanogram or picogram levels. Response times of bromide and chloride electrodes were established to concentration and flow-rate changes in a flowing stream. When flow-rate was Increased, response time of electrode decreased, but response volume Increased. Response time was decreased for low activities rather than high activities of solute ion when flow-rate Increased. At high flow-rates, response time was Independent of the activity of the solute Ion. Also a new approach to the definition of the response time in flowing conditions was purposed In order to be able to Indicate their performances. An evaluation of the Influence and contribution of the sample dispersion on the sensitivity of tubular liquid membrane bromide selective electrode based on PVC was examined with a new, easy reliable approach In a flow-injection system for chromatographic measurements. Using water as carrier, it was observed that the dispersion influence was completely dependent on the response time of electrodes. When sample In the carrier passes through the electrode surface just within the electrode response time, better peak shape and sensitivity were obtained at each flow-rate, whilst shorter remaining time of sample caused tailing and decreasing of the sensitivity, longer remaining time caused peak broadening. An all solid-state tubular PVC-matrix membrane electrode as detector In non-suppressed Ion chromatography was employed Jor detection of some monovalent common anions Including I and SO at sub-ppb levels. Non-supprýessed separation of halides and strongly retained anions I and SCN In one run was achieved using Phosphate solution as a new efficient eluent over Dionex IonPac-AS4A and AG4A columns. Potentlometric detection of eleven monovalent Inorganic and organic anions with the use of all solid-state contact tubular membrane electrode (cell volume 2 pl) as detector In non-suppressed Ion chromatography was demonstrated using phosphate and hydrogen phosphate as eluents at low concentrations. Theoretical and practical considerations were discussed, and In particular, sensitivity, linearity, detection limit and dynamic behaviour were presented. Applications to river, drinking and rain water samples were described. In any liquid chromatographic technique, the eluent composition provides greatest flexibility for manipulating the retention of solutes In order to achieve a desired separation. Utilizations of a new composition of the 11CO 3 /CO 32 buffer solution or phosphate solution as eluents were demonstrated for the separation of twelve Inorganic and organic anions with good resolution in six minutes using Dionex-100 ion chromatographic system. A simple and selective method for single Ion chromatographic 11 separation (in seven mlnVtesý and potentiom+etric detection (at sub-ppb levels) of Na"', Nil 4, K. Rb +0 THA +0 Cs and Tl+ cations was established using copper and magnesium salts as eluents, with Dionex IonPac-CS3 analytical and guard columns and all solid-state contact tubular membrane potassium selective electrode as detector. The application of the method for drinking, river, spring, sea water samples and orange juice, urine and saliva samples were illustrated. As the detector was highly selective and sensitive to only monovalent cations, no Interference from other cations, the method was easily applIjd to mjny sample types examples Including the determination of Na and K, on the surface of the glassware adsorbed during the fabrication stage, and In many inorganic and organic chemicals were given. It might be the over-all efficiency of Ion chromatographic procedures that allows the routine separation and detection of Inorganic and organic anions and cations at low levels in a simultaneous system. A simple, selective, sensitive reproducible and rapid method needing only 8 minutes or less to complete a simultaneous potentiometric detection and Independent separation of a group of fourteen Inorganic and organic monovalent common anions and cations was developed using copper or magnesium sulphate salt as eluents with Dionex 1onPac-AS4A and -CS3 anion and cation-exchange columns In tandem. The only difference of the method from other simple chromatographic applications was just one more chromatographic column and one more potentiometric detector. The method was flexible, as the anions will not Interfere with the detection of cations or cations will not Interfere with the detection of anions, that detectors can be used at the end of the two column In tandem or one can be used af ter f Irst column. The first column can be anion or cation-exchange. A method for simultaneous determination of sodium, potassium and chloride In bovine serum albumin plasma was established. it Involved Independent Ion chromatographic separation on anion and cation- exchange columns and simultaneous potentiometric detection by anion and cation selective electrodes. The concentrations of monovalent cations and chloride was Increased with the Increasing of dilution of non-filtered sample, there was no significant changes In the concentrations determined In the sample which was filtered.
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Bissonnette, Martine C. "Ion/radical and ion/molecule complexes and ion structure assignments in the gas phase." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7731.
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The fragmentation mechanism of ionized neopentanol, (CH$\sb3$)$\sb3$CCH$\sb2$OH$\sp{+-}$, has been studied in great detail along with other C$\sb5$H$\sb $H$\sp{+-}$ isomers. The use of $\sp $C and D labelling was found an essential tool to establish the relation between the other species involved in the dissociation of neopentanol. The involvement of (CH$\sb3$)$\sb2$C$\sp{\cdot}$CH$\sb2\sp+$(O)HCH$\sb3$, (CH$\sb3$)$\sb3$C$\sp+$(O)HCH$\sb2$ and (CH$\sb3$)$\sb2$($\sp\cdot$CH$\sb2$)CCH$\sb2\sp+$OH$\sb2$ was essential to explain the H/D label exchange occurring upon fragmentation of neopentyl alcohol. An ion-dipole complex between methanol and ionized methyl propene is proposed as the final intermediate which leads directly to the products, methanol and ionized methyl propene. The results of the investigation of C$\sb7$H$\sb5\sp+$ ions from various precursor molecules are also described. The following compounds, which all produce C$\sb7$H$\sb5\sp+$ ions, were studied: benzyl acetate, benzyl formate, benzyl alcohol, 2-bromocyclopropabenzene, 1,6-heptadiyne and 1,5-decadiyne. According to the metastable ion (MI) mass spectra and the He collision induced dissociation (CID) of m/z 89 ions, it is suggested that four structures exist. (Abstract shortened by UMI.)
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Marto, Jarrod A. "External Ion Injection and Applications of Ion Axialization in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487868114113087.
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Diédhiou, Malick. "Ion Chemistry of Hydrogenated PAHs." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40452.
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Polycyclic aromatic hydrocarbons (PAHs) are a class of organic molecules suggested to constitute roughly 20% of carbon in the interstellar medium (ISM). These species exist in both neutral and ionic forms and both are potentially involved in processes such as H2 formation. Catalyzing H2 formation necessarily involves the participation of hydrogenated PAHs as reaction intermediates. Employing tandem mass spectrometry and imaging photoelectron photoion coincidence spectroscopy and theory, we have explored the unimolecular reactions of five ionized hydrogenated PAHs that vary in degree and position of hydrogenation: tetralin (1,2,3,4-tetrahydronaphthalene), 9,10-dihydroanthracene (DHA+•), 1,2,3,4-tetra- and 1,2,3,4,9,10-hexa-hydrophenanthrene (THP+• and HHP+•) and 1,2,3,4,5,6,7,8-octahydroanthracene (OHA+•). The major reactions observed were the losses of the hydrocarbons CH3•, C2H4 and C3H5• together with H• atom loss. RRKM modeling of the iPEPICO data suggested that the unimolecular chemistries were based around a two-well potential energy surface in each case. Ionized tetralin can lose all four neutrals via H-shift and ring-opening reactions, or CH3• and C2H4 after interconversion to the 1-methylindane ion, a process similar to that found for ionized 1,2-dihydronaphthalene (isomerizing to form the 1-methylindene ion structure). DHA+• exhibits the same reactions previously observed for 1,2-dihydronaphthalene and 9,10-dihydrophenanthrene, namely competing loss of H• and CH3•. However, the energy required for H•-loss, as predicted by RRKM modeling of the iPEPICO results, was lower than the latter ions, presumably due to an expansion of the electron delocalization across the central ring upon dehydrogenation. OHA+• behaves similarly to ionized tetralin, displaying losses of H•, CH3•, C2H4 and C3H5• in its collision induced dissociation (CID) mass spectra, but under iPEPICO conditions CH3•-loss is not observed. THP+•
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and HHP+• have aspects of both DHA+• and OHA+• chemistries, displaying losses of H•, CH3•, C2H4 and C3H5•. Minimum energies for all observed reaction channels were thus obtained, together with selected mechanisms computationally explored at the B3-LYP/6-31+G(d,p) level of theory. The trend in reactivity in going from tetralin and DHA+• to THP+•, HHP+• and ultimately OHA+• sees decreasing abundance of H• and CH3•-loss and an increasing dominance of the formation of C2H4, C3H5• and higher hydrocarbons with degree of hydrogenation as isomerization to a methyl-substituted ion becomes less significant. As this isomerization decreases in significance, the ions become sources of small hydrocarbon molecules and not hydrogen atoms or molecules.
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Hall, Adrian Mark. "Composition and morphology of substorm-associated ion injections." Thesis, University of Leicester, 1997. http://hdl.handle.net/2381/30662.
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This thesis describes an investigation into the composition and morphology of substorm ion injections at magnetic latitudes and L-shells away from geostationary orbit. Furthermore, the work investigates the Dst-dependent conditions that affect these compositional and spatial characteristics. Count rate and composition measurements in the energy range 80 - 400 keV/q form the basis of the analysis. Near-equatorial observations by the CRRES spacecraft during 1991 have been used to study substorm and near-Earth magnetosphere composition, injection event distribution, and the injection region morphology. Measurements made by the Polar satellite during 1996 extend the study to high magnetic latitudes (50 - 60 °) and high L-shells (7 ≤ L ≤ 22), and are used to investigate the radial morphology of the injection region. For the first time, substorm injection rate as a function of composition, Dst, and injection type has been quantified. In storm time the rate more than doubles. This appears to result from the observed increase in the azimuthal extent of the average injection region. Analysis has shown however, that substorm onset and type (single or multiple injection events) are (for the most part) not significantly composition dependent. The threefold increase in ionospheric-rich event frequency during storm time is principally a result of the increase seen in the equatorial, dusk flank event occurrence. Ion injections have been observed over a large radial extent. Furthermore, ions drift coherently over a large range of L-shells, spanning, at times, from geostationary orbit to L ≈ 18. The inward transport of these ions is not composition dependent. The injected plasma depends on the magnetospheric composition tailward of the spacecraft. This is highly spatially variable and dependent on the past, and prevailing Dst conditions with large (fourfold) enhancements in ionospheric origin material observed inside of L ≈ 7 ( i.e. below the altitude of most substorm onsets) during storm time. The storm time nightside ring current is observed to expand both earthward and tail ward. Out of the equatorial plane, the injection rate is hypothesised to artificially decrease as a result of the tapered, crescent shaped form of the injection region.
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Pollum, Laura L. "Digital ion trap mass spectrometry for cold ion-molecule chemistry." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:18c6451d-d247-4384-9257-f8864e038343.
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A promising new approach for studying cold ion-molecule chemical reactions is the combination of laser- or sympathetically-cooled trapped ions and slow-moving molecules from a cold molecule source, such as a quadrupole velocity selector or a Stark decelerator. Previous reaction studies using trapped atomic ions and slow molecules from a quadrupole velocity selector were able to reach average collision energies as low as 1 K. However, the guided molecules had an approximately room temperature rotational energy distribution, so the reactions studied were not truly cold. Thus, a new molecular source for producing translationally and rotationally cold molecules utilizing buffer gas cooling and quadrupole velocity selection was constructed by K. Twyman and characterized for use in cold reaction studies. This new source of cold molecules is referred to as the buffer gas guide. A new ion trap has been designed and built for use with the existing buffer gas guide. The new ion trap apparatus is compact and mechanically compatible with this new guide. It uses a linear Paul ion trap with cylindrical electrodes to trap ions. Two optical axes (one axial and one radial) enable efficient cooling of small ion crystals. A field-free time-of-flight tube and ion detection assembly are also incorporated into the apparatus. A new technique for determining the mass and quantity of trapped ions has also been developed, termed digital ion trap mass spectrometry. The new technique uses a digital RF waveform to trap ions before ejecting the ions radially from the trap using an ejection pulse applied to the trap electrodes. The ions are then detected after free flight along a time-of-flight tube. This technique was characterized by ejecting crystals of various sizes and compositions: Ca<sup>+</sup> only, Ca<sup>+</sup>/CaF<sup> +</sup>, Ca<sup>+</sup>/CaOH<sup> +</sup>/CaOD<sup>+</sup>, and Ca<sup>+</sup>/NH<sup> +</sup><sub style='position: relative; left: -.6em;'>3</sub> /NH<sup> +</sup><sub style='position: relative; left: -.6em;'>4</sub> /H<sub>3</sub>O<sup>+</sup>. A linear relationship between the number of ions ejected (determined by comparing experimental and simulated crystal images) and the integral of the time-of-flight peak was observed for Ca<sup>+</sup> and Ca<sup>+</sup>/CaF<sup> +</sup>. All mass peaks were resolved. Simulations of the trapped ions and their trajectories through the time-of-flight tube were also performed, and excellent agreement between the simulated and experimental mass resolution was observed. Progress towards combining the buffer gas guide with the previously independent ion trap is also presented. It is anticipated that the combined buffer gas guide ion trap apparatus will enable the study of ion-molecule reactions at low temperatures with translationally and rotationally cold molecules. It is anticipated that the new digital ion trap mass spectrometry technique will simplify the study of reactions when multiple product ions whose masses are separated by only 1 AMU are formed. A new ion trap has been designed and built for use with the existing buffer gas guide. The new ion trap apparatus is compact and mechanically compatible with this new guide. It uses a linear Paul ion trap with cylindrical electrodes to trap ions. Two optical axes (one axial and one radial) enable efficient cooling of small ion crystals. A field-free time-of-flight tube and ion detection assembly are also incorporated into the apparatus. A new technique for determining the mass and quantity of trapped ions has also been developed, termed digital ion trap mass spectrometry. The new technique uses a digital RF waveform to trap ions before ejecting the ions radially from the trap using an ejection pulse applied to the trap electrodes. The ions are then detected after free flight along a time-of-flight tube. This technique was characterized by ejecting crystals of various sizes and compositions: Ca+ only, Ca+/CaF+, Ca+/CaOH+/CaOD+, and Ca+/NH+3/NH+4/H3O+. A linear relationship between the number of ions ejected (determined by comparing experimental and simulated crystal images) and the integral of the time-of-flight peak was observed for Ca+ and Ca+/CaF+. All mass peaks were resolved. Simulations of the trapped ions and their trajectories through the time-of-flight tube were also performed, and excellent agreement between the simulated and experimental mass resolution was observed. Progress towards combining the buffer gas guide with the previously independent ion trap is also presented. It is anticipated that the combined buffer gas guide ion trap apparatus will enable the study of ion-molecule reactions at low temperatures with translationally and rotationally cold molecules. It is anticipated that the new digital ion trap mass spectrometry technique will simplify the study of reactions when multiple product ions whose masses are separated by only 1 AMU are formed.
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Murrell, Jason. "Some studies in ion/molecule reactions on ion trapping instruments." Thesis, University of Kent, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319223.
Full textBooks on the topic "Ion chemistry and composition"
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Mamontov, Vladimir. Soil chemistry: a practical course. INFRA-M Academic Publishing LLC., 2023. http://dx.doi.org/10.12737/1079438.
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The textbook describes methods for analyzing the elemental composition of the mineral part of soils, ways to express the results of gross analysis and recalculation of analytical data. Methods for studying the ion-salt complex of soils and available forms of plant nutrition elements, as well as methods used to determine the total humus and nitrogen, group and fractional composition of humus, and methods for studying some properties of humic acids are presented. The use of gross analysis data, the results of studying the ion-salt complex and soil organic matter for practical purposes is considered.
 Meets the requirements of the federal state educational standards of higher education of the latest generation.
 It is addressed to students of higher educational institutions studying at the faculties of soil Science, agrochemistry and ecology in the field of training "Agrochemistry and agro-soil science", as well as graduate students and researchers specializing in soil science, agrochemistry, ecology and agronomy.
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W, Neilson G., and Enderby J. E, eds. Water and aqueous solutions: Proceedings of the Thirty-seventh Symposium of the Colston Research Society, held in the University of Bristol in April 1985. A. Hilger, 1986.
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Serebryakov, Andrey, Tat'yana Smirnova, Valentina Mercheva, and Elena Soboleva. Chemistry of combustible minerals. INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1041945.
Full textAbstract:
This textbook is a publication of the latest generation, designed to optimize the national project "Education"; develops theoretical knowledge about the genesis of natural liquid, gaseous and solid combustible minerals, the formation of the composition and properties, the practical significance of fuel and energy natural complexes. It is devoted to the study of the composition, properties and classification of oils, gas condensate, natural gases and solid combustible minerals, studied at the level of modern achievements of instrumental analytical and factory equipment in accordance with existing technologies, theories and hypotheses about the genesis of hydrocarbons and Earth sciences. The publication is supplemented with the main directions of processing of combustible minerals. Digital and graphical types of chemical models of the synergy of components of gas and oil deposits are described, which are necessary for predicting the phase state and composition of hydrocarbons and optimizing the directions of processing of marketable products. To facilitate the process of cognition of the origin and formation of the composition and properties of natural combustible minerals, a glossary, tests, as well as questions for the test and exam are offered.
 To control the knowledge gained by students while studying textbook materials, each chapter is accompanied by questions and tasks.
 Meets the requirements of the federal state educational standards of higher education of the latest generation.
 It is intended for students studying in the fields of 05.04.01, 05.03.01 "Geology", 21.05.02 "Applied Geology", as well as for specialists in the field of geology, geochemistry, extraction and processing of oil, gas, gas condensate, solid fuels.
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Surkova, Galina. Atmospheric chemistry. INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1079840.
Full textAbstract:
The textbook contains material corresponding to the course of lectures on atmospheric chemistry prepared for students studying meteorology and climatology. The basic concepts of atmospheric chemistry are given, its gaseous components, as well as aerosols and chemical processes related to their life cycles, which are important from the point of view of the formation of the radiation, temperature and dynamic regime of the atmosphere, as well as its pollution, are considered. The main regularities of the transport of impurities in the atmosphere and the role of processes of different spatial and temporal scales in this process are presented. The concept of approaches of varying degrees of complexity used to model the transport of matter in the atmosphere, taking into account its chemical transformations, is presented. The processes in the gaseous and liquid phases that affect the chemical composition and acidity of clouds and precipitation are described. Modern methods of using information about the concentration and state of chemical compounds, including their radioactive and stable isotopes, to obtain information about the meteorological regime of the atmosphere in the present and past are considered.
 Meets the requirements of the federal state educational standards of higher education of the latest generation.
 For students of higher educational institutions studying in the field of training "Hydrometeorology".
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Ryabov, Vladimir. Oil and Gas Chemistry. INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1017513.
Full textAbstract:
The textbook provides up-to-date data on the composition and properties of hydrocarbons and other oil and gas compounds, on the physical and chemical methods and methods for separating and identifying oil components (molecular spectroscopy, mass spectrometry, NMR spectroscopy, electron paramagnetic resonance, atomic adsorption spectroscopy, neutron activation analysis). The chemistry and mechanism of thermal and catalytic transformations of oil components in the main processes of oil raw materials processing, as well as the problems of the origin of oil and the transformation of oil in the environment are considered.
 Meets the requirements of the federal state educational standards of higher education of the latest generation.
 It is intended for training in the course "Chemistry of oil and gas", for the preparation of bachelors, masters and certified specialists in the field of training "Oil and Gas business". It can be used for training in other areas in oil and gas universities and be of interest to specialists working in the field of chemistry and technology of oil refining and in other areas of the oil and gas industry.
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S, Levine Joel, Langley Research Center, United States. Office of Space Science and Applications, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch, eds. Space opportunities for tropospheric chemistry research: Proceedings of a workshop. National Aeronautics and Space Administration, Scientific and Technical Information Branch, 1987.
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Freiser, Ben S., ed. Organometallic Ion Chemistry. Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0111-7.
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S, Freiser Ben, ed. Organometallic ion chemistry. Kluwer Academic Publishers, 1996.
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Brimblecombe, Peter. Air: Composition & chemistry. Cambridge University Press, 1986.
Find full textBook chapters on the topic "Ion chemistry and composition"
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Sethi, Shruti, Alka Joshi, Bindvi Arora, and O. P. Chauhan. "Chemical Composition of Foods." In Advances in Food Chemistry. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-4796-4_1.
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Burgot, Jean-Louis. "Solvents—Composition of Solutions." In Ionic Equilibria in Analytical Chemistry. Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-8382-4_1.
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Li, Li, Joseph P. Kenny, Meng-Shiou Wu, et al. "Adaptive Application Composition in Quantum Chemistry." In Lecture Notes in Computer Science. Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-02351-4_13.
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Becagli, Silvia. "Aerosol Composition and Reactivity." In Atmospheric Chemistry in the Mediterranean Region. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-82385-6_13.
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Irvine, William M. "The Molecular Composition of Dense Interstellar Clouds." In Chemistry in Space. Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-009-0695-2_4.
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Feldman, Paul D. "The Volatile Composition of Comets Deduced from Ultraviolet Spectroscopy." In Chemistry in Space. Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-009-0695-2_13.
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Allen, Ralph O., Hany Hamroush, and Michael A. Hoffman. "Archaeological Implications of Differences in the Composition of Nile Sediments." In Advances in Chemistry. American Chemical Society, 1989. http://dx.doi.org/10.1021/ba-1988-0220.ch003.
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Alvarado, Matthew J., Kelley C. Barsanti, Serena H. Chung, Daniel A. Jaffe, and Charles T. Moore. "Smoke Chemistry." In Wildland Fire Smoke in the United States. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-87045-4_6.
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AbstractSmoke chemistry (i.e., chemical transformations taking place within smoke plumes) can alter the composition and toxicity of smoke on time scales from minutes to days. Air quality agencies need better information on and better models of smoke chemistry to more accurately characterize the contributions of smoke to ambient ozone and particulate matter, and to better predict good windows for prescribed burning. The ability of these agencies to quantify the contributions of wildland fires to air pollutants and the ability of forest and burn managers to both predict and mitigate these impacts are limited by how current models represent smoke chemistry. This limitation is interconnected with uncertainties in smoke emissions, plume dynamics, and long-range transport. Improving predictive models will require a combination of laboratory, field, and modeling studies focused on enhancing our knowledge of smoke chemistry, including when smoke interacts with anthropogenic emissions and enters indoors.
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Varelas, C. G., A. J. Dualeh, and C. A. Steiner. "Microdomain Composition in Two-Phase Hydrogels." In Macromolecular Complexes in Chemistry and Biology. Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/978-3-642-78469-9_5.
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Evlanov, E. N., M. N. Fomenkova, V. N. Khromov, et al. "Features of Experimental Studying of Comet Halley Dust Particles Elemental Composition." In Chemistry in Space. Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-009-0695-2_15.
Full textConference papers on the topic "Ion chemistry and composition"
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Hock, V. F., J. E. Suarez, J. H. Givens, and J. M. Rigsbee. "Structure, Chemistry, and Properties of Mixed Metal Oxides." In CORROSION 1988. NACE International, 1988. https://doi.org/10.5006/c1988-88230.
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Abstract Electrically conductive metal oxide coatings have been produced by thermal decomposition and reactive ion plating for application in cathodic protection systems. Ceramic materials are advantageous because of their very low dissolution rates (typically less than 1 g/amp/yr in 3.5% NaCl solution) and ease of fabrication. X-ray diffraction, scanning electron microscopy (SEM), Auger electron spectroscopy (AES), and energy dispersive x-ray spectroscopy (EDS) are used for characterization and subsequent discussion of the microstructure, crystallography, and elemental composition of both types of coatings.
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Garsany, Yannick, Derek Pletcher, and Bill Hedges. "The Role of Acetate in CO2 Corrosion of Carbon Steel: Has the Chemistry Been Forgotten?" In CORROSION 2002. NACE International, 2002. https://doi.org/10.5006/c2002-02273.
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Abstract The influence of acetate ion on the rate of corrosion of carbon steel (X65) in 3 % NaCl brine saturated with carbon dioxide has been investigated using voltammetry at a rotating disc electrode. It is shown that the rate of corrosion can only be understood if it is recognised that the cathodic process in the steel corrosion does not distinguish between the reduction of free protons and the reduction of the undissociated proton donor, acetic acid. Hence, for any brine composition it is important to consider the concentration of acetic acid as well as the pH of the brine in explaining the rates of corrosion of the steel. This requires the ability to predict the speciation of these complex solutions.
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Elboujdaini, M., J. Li, V. Gertsman, et al. "Stress Corrosion Cracking: Microstructural and Material Properties for Crack Initiation of 16" X-52 Line Pipe Steel." In CORROSION 2004. NACE International, 2004. https://doi.org/10.5006/c2004-04553.
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Abstract To better understand the mechanism for stress corrosion cracking (SCC) the advanced analytical tools, including high-resolution scanning electron microscope (SEM), focus ion beam (FIB) and transmission electron microscope (TEM) were used. The complexity of stress corrosion cracking results from the dependence of SCC on composition of the steel, applied stress, water chemistry in the field, and ionic concentrations in the groundwater near the pipe surface, may all have an effect on crack initiation and propagation.
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Amjad, Zahid, Libardo Perez, and Robert W. Zuhl. "Water Chemistry Impacts on Cooling Water System Iron Oxide Dispersants." In CORROSION 2015. NACE International, 2015. https://doi.org/10.5006/c2015-05996.
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Abstract The effects of water chemistry such as total dissolved solids, polyvalent metal ions, pH, and temperature on particulate iron oxide dispersion by a variety of polymeric additives have been investigated. The deposit control polymers (DCPs) evaluated include synthetic polymers (of varying composition and molecular weight). Results reveal that DCP iron oxide dispersant performance strongly depends on dosage and architecture (e.g., type and amount of monomers, monomer functional group ionic charge, molecular weight). Data show that pH changes cause varying but relatively small changes in DCP dispersant performance. The results also suggest that low levels of divalent and trivalent metal ions reduce DCP dispersant performance.
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Jordan, M. M., C. J. Johnston, T. M. O’Brien, and P. Hopwood. "Integrated Field Management to Allow Effective Scale Control During the Water Cycle in Mature Oil Fields." In CORROSION 2006. NACE International, 2006. https://doi.org/10.5006/c2006-06394.
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Abstract Scale control within produced fluids as water follows the cycle of injection, production, processing and reinjection in oil/gas production facilities is critical to the effective production of hydrocarbons in a safe, economic and environmentally acceptable manner. The scale challenges associated with seawater injection into a South American offshore reservoir with a moderate Barium Sulfate scale challenge (180 ppm Barium within the formation water) are described. An integrated scale management strategy addresses these issues based on tracking production rates, ion chemistry changes and amount/composition of the suspended solids to evaluate the requirement to scale squeeze the production wells. The impact of the reservoir stripping mechanism on scale ions concentration and the resulting impact on scale inhibitor chemical required to control scale is outlined. The selection of scale inhibitors for scale squeeze application, the optimization of these treatments to enhance squeeze life is also demonstrated.
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Dilie, Eldon R. "Possible Effects of Closed Loop Operation on Boiler Chemistry." In CORROSION 1996. NACE International, 1996. https://doi.org/10.5006/c1996-96466.
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Abstract Closed loop operation of power plant equipment can result in concentration of selected ions. In order to illustrate the concentration phenomina that occurs in closed loop operation, an analogy is being made to a flue gas desulfurization system in this paper. The information presented in this paper was obtained on the closed loop operation of a flue gas desulfurization (FGD) system is described with all streams in and out of the closed loop defined and monitored. The composition of the coal remained uniform during the test period of 60 days. The water balance of the FGD system was maintained closed loop during the test period. Closed loop FGD operation means the only water leaving the FGD system is through evaporation in the cooling and saturating of the flue gas and the loss of water in the solids which are removed from the FGD system.
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Shifler, David A., and Denise M. Aylor. "Considerations for the Testing of Materials and Components in Seawater." In CORROSION 2002. NACE International, 2002. https://doi.org/10.5006/c2002-02217.
Full textAbstract:
Abstract Seawater is an aggressive, complex fluid that affects nearly all common structural materials to some extent. There are two competing processes that operate simultaneously in seawater environments: (1) the chloride ion activity tends to destroy the passive film, and (2) dissolved oxygen, which acts to promote and repair the passive film on metallic materials of construction. Metals and alloys that develop protective films by the formation of thin metal oxides can have the formation of passive films be delayed or have films destroyed by chloride ions in seawater. The type of corrosion testing required depends on the extent and type of information desired and the environmental conditions expected in service for the alloy component. Seawater corrosion is dependent on a number of factors such as alloy composition, water chemistry, pH, biofouling, microbiological organisms, pollution and contamination, alloy surface films, geometry and surface roughness, galvanic interactions, fluid velocity characteristics and mode, oxygen content, heat transfer rate, and temperature. Understanding how these factors may affect experimental results can help the design of seawater corrosion testing to minimize experimental variations and best simulate service conditions.
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Hansen, Douglas C., David Borth, and Farrah Cole. "Characterization of the Surface Chemistry at Corroded and Non-Corroded Sites on Aluminum Alloy 7075-T6 Samples Exposed at Coastal Locations." In CONFERENCE 2022. AMPP, 2022. https://doi.org/10.5006/c2022-17642.
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Abstract Replicate samples of bare aluminum alloy AA7075-T6 were exposed at three coastal atmospheric test sites: Kennedy Space Center (KSC) FL, US Naval Research Laboratory in Key West, FL (NRL-KW), and Daytona Beach, FL. The samples were cross sections of rod stock mounted in standard two-part epoxy metallurgical mounts and wet polished with isopropanol to 600 grit finish. The samples were installed on atmospheric exposure racks and retrieved at intervals of 3, 6, 9, and 12 months. Elemental composition of baseline (non-exposed) and exposed samples were measured using a Zeiss EVO-50XP Environmental Scanning Electron microscope equipped with a EDAX Genesis 2000 energy dispersive X-ray spectroscopy (EDS) system. Pitted and non-pitted sites on each sample were analyzed for compositional elements of the alloy as well as non-compositional elements (i.e. environmentally-derived). It was determined that the deposition of elements in pitted locations on the specimens occurred at concentrations of 200% to 800% to that of major ions present in natural seawater. The deposition and concentration of these environmentally derived elements on the metal surface vary as a function of exposure site and length of exposure time.
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Bruemmer, S. M., L. A. Chariot, and E. P. Simonen. "Grain Boundary Chemistry Effects on Irradiation-Assisted Stress Corrosion Cracking." In CORROSION 1990. NACE International, 1990. https://doi.org/10.5006/c1990-90506.
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Abstract Radiation-induced segregation (RIS) to grain boundaries and interfacial microchemistry effects on intergranular stress corrosion cracking (IGSCC) have been investigated in 304 and 316 stainless steels (SS). Irradiation dose effects on RIS to grain boundaries were studied using nickel ion bombardment of fine-grained, sputter-deposited SS. Damage levels from 1 to 20 dpa were produced in near-surface regions encompassing several grain diameters in depth. The resultant "bulk" damage promoted RIS of silicon and nickel, as well as depletion of chromium at grain interfaces. Maximum enrichment/depletion ratios of about 4.0, 1.1 and 0.7 were measured for silicon, nickel and chromium, respectively. Composition changes were localized to within 20 nm of the boundary as measured by analytical transmission electron microscopy. No grain boundary enrichment of phosphorus was observed in these heats even though heats contained high levels of phosphorus in the bulk. Grain boundary chemistry effects on the intergranular (IG) corrosion and stress corrosion cracking (SCC) were examined by varying phosphorus segregation and chromium depletion through controlled thermal treatments. Grain boundary enrichment of phosphorus was found to promote IG corrosion, but not SCC, of 316 SS in low-temperature, sulfuric acid solutions at transpassive potentials. Results from slow-strain-rate, straining-electrode tests at various anodic (active to transpassive) potentials show no evidence that grain boundary phosphorus enrichment (without chromium depletion) promotes IGSCC. Phosphorus segregation did promote IG hydrogen cracking at cathodic potentials. The fracture mode changed from transgranular (TG) to IG as the phosphorus at the boundary reached about 8% of a monolayer. This fracture mode transition corresponds to a drop in ductility from approximately 70% strain-to-failure (&lt;5% of a monolayer phosphorus) to 15% strain-to-failure (&gt;8% of a monolayer phosphorus). Chromium depletion is shown to promote IG attack at active/passive potentials in a low-temperature sulfuric acid solution and IGSCC in high-temperature water. The minimum chromium concentration at the grain boundary controlled both corrosion and cracking susceptibility for 304 SS. Grain boundary chromium minimums below about 13 wt% induced IG attack during electrochemical potentiokinetic reactivation (EPR) experiments, while minimums up to 14 wt% prompted IGSCC in slow-strain-rate tests in 300 C oxygenated water. The transition from TG to IG fracture was mapped as a function of minimum chromium level on specimens where the depletion width was constant (~50 nm). Ductility was found to drop consistently with the decrease in chromium minimum and the increase in IG fracture. The implications of these results on current understanding of irradiation-assisted SCC are discussed.
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Videla, H. A., M. R. Viera, P. S. Guiamet, and J. C. Staibano Alais. "Combined Action of Oxidizing Biocides for Controlling Biofilms and MIC." In CORROSION 1994. NACE International, 1994. https://doi.org/10.5006/c1994-94260.
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Abstract Laboratory experiments under well defined conditions (water chemistry, microbial strains, substrata composition, and experimental techniques) were made to assess the biocidal action of ozone on pure and mixed bacterial biofilms. Bacterial biofilms of Pseudomonas fluorescens, or anaerobic biofilms of two different strains of sulphate-reducing bacteria, were exposed to ozone concentrations within the range of 0.2 to 1 ppm under quiescent conditions. Biofilms were formed on SAE 1020 carbon steel and on AISI type 304L stainless steel samples. The effect of ozone on the corrosion behavior of these metals, as well as the possible synergistic effect of ozone/bromide mixtures were also studied. Ozone was effective not only to kill bacteria but also to facilitate the detachment of bacterial biofilms formed on stainless steel. However, this detachment was not observed on carbon steel samples. Preliminary experiments showed that ozone-bromide ion mixtures do not modify either the biocidal action or the corrosion behavior of the metals with respect to that obtained with ozone alone.
Reports on the topic "Ion chemistry and composition"
1
Moghissi. L51914 Interdependent Effects of Bacteria Gas Composition and Water Chemistry on Internal Corrosion. Pipeline Research Council International, Inc. (PRCI), 2002. http://dx.doi.org/10.55274/r0010433.
Full textAbstract:
A recent Office of Pipeline Safety survey found that corrosion caused 17 to 20 percent of pipeline failures. Of those corrosion failures, roughly half resulted from internal corrosion. In pipelines, internal corrosion is caused by produced (carry-over) or condensed water that contains dissolved gas and/or bacteria. In many cases, chemicals with inhibiting or biocidal properties are added to mitigate corrosion. The internal corrosion in many systems occurs under slowly flowing conditions at ambient temperatures (e.g., relatively low temperature of about 15.5�C (60�F)). The overall objectives of this project were to determine the influence of microbial consortia typically found in condensed water, produced water, and hydrocarbons on the internal corrosion of steel pipeline exposed to CO2, H2S, and O2. To accomplish these objectives, a multi-year project was planned. For the first year, the specific objectives were to assemble a chemostat system capable of maintaining a mixed biofilm consortium of bacteria implicated in MIC of steels under the pressures encountered in gathering lines, identify the type of microbial populations inside pipelines and conditions under which internal MIC has been observed, and perform a limited number of corrosion tests to evaluate the effects of these bacteria on corrosion.
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Sridhar and Dunn. L51793 The Effects of Water Chemistry on Internal Corrosion of Steel Pipelines. Pipeline Research Council International, Inc. (PRCI), 2000. http://dx.doi.org/10.55274/r0010425.
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The ability to safely transport wet, untreated natural gases through pipelines offshore or at other inaccessible locations is an important factor in the development of new gas fields. The internal corrosion rate of steel pipelines varies in a complex way with the gas composition, specifically CO2 , O2 , and H2 S, and condensed water chemistry. Estimating the corrosion rate of steel at inaccessible locations from the analysis of the gas and water composition from an accessible location will enable a better determination of the need for corrosion inhibitors. Quantitative understanding of the corrosion rate of steel under these conditions will be key to an accurate risk assessment of pipelines from internal corrosion. Previous work examined the effects of gas composition and slow liquid flow conditions on corrosion of steel. A parametric equation was developed that essentially reflected the deleterious effects of CO2 and O2 , and the beneficial effect of H2S on corrosion (Lyle, 1997). While this study provided important information regarding the deleterious effect of oxygen in the gas phase, the effects of condensed water composition, especially scale-forming species such as calcium and magnesium, were not examined. Furthermore, a better thermodynamic and kinetic understanding of the effects of the gas and liquid phase composition was needed. The present project, while an extension of the previous project, breaks important new ground: (i) the water chemistry typically found in pipelines is included in the tests; (ii) the scale and corrosion product formation is examined using a thermodynamic speciation software; (iii) surface analysis of the corroded samples is performed using laser Raman spectroscopy in order to confirm the thermodynamic model prediction; and (iv) electrochemical tests are conducted to understand the corrosion kinetics. A discussion of the general literature on internal corrosion is presented in the next section, followed by a summary of results from previous SwRI projects in this area. The thermodynamic approach and results are presented in Chapter 2. The experimental results are presented in Chapters 3 and 4, respectively, along with a discussion of the results in terms of thermodynamic and kinetic framework. Chapter 5 summarizes the results of this project and provides recommendations for further investigations. Details of the thermodynamic calculations, electrochemical experimental results, and analyses of the corrosion products are presented in the appendices.
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Hedrick, Jacob, and Timothy Jacobs. PR-457-14201-R02 Variable NG Composition Effects in LB 2S Compressor Engines Phase I Engine Response. Pipeline Research Council International, Inc. (PRCI), 2015. http://dx.doi.org/10.55274/r0010997.
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This is the final report summarizing work completed during the first phase of the PRCI study on large bore two stroke lean burn integral compressor engine response to variable natural gas compositions for the purposes of engine control development. Accomplished tasks include the completion of a detailed literature review covering the research topic, a parametric study of laminar flame speeds and ignition delays for binary methane and ethane mixtures up to 30%, and a GT-Power engine model of the Colorado State GMV-4 research engine with associated validation data from CSU�s variable ethane effects study. The chemistry of the combustion reaction is crucial to accurate modeling; laminar flame speeds and ignition delays as function of composition were determined from the solutions to published chemical kinetics mechanisms GRI-Mech3.0 and Saudi Aramco Mech1.3, respectively. The Wiebe coefficients correlated to variations in ethane composition and spark timing were regressed from the crank angle resolved heat release rates. The Wiebe coefficients are the most significant achievement of this phase of the project, since they quantify the heat release as a function of composition. At this time, the Wiebe parameters only reflect the relative changes in the model since certain aspect of the models geometry are pending resolution. Future phases of the project could use the developed GT-Power model and Wiebe coefficients for development of control schemes that maintain emissions, speed and torque limits, and maximize thermal efficiency during a variable fuel composition event.
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Reid, M. S., X. Wang, N. Utting, and C. Jiang. Comparison of water chemistry of hydraulic-fracturing flowback water from two geological locations at the Duvernay Formation, Alberta, Canada. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/329276.
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We analyzed and compared the water chemistry between 17 Fox Creek region samples, each from a different well, and 23 Three Hills region samples from a single well. Overall, the two regions were similar in chemical composition but showed small differences in some lower abundance dissolved elements. Additionally, we investigated changes in water chemistry of FPW over time from a single well. The majority of water quality parameters and water chemistry remained constant over the 7-month sampling time. Major ion chemistry showed increasing concentrations of Ca and Mg, and a decreasing concentration of SO4. Several trace elements also showed small trends of both increasing and decreasing concentrations over time. There was a strong correlation between Ca and Mg concentrations in both the Fox Creek region samples and Three Hills region samples, which is an indication of the mixing of formation water. However, the correlation between B and Sr was different among two region samples, which is likely due to the delayed mixing of formation water with the fracturing fluids during the flowback at different time periods of post fracturing. Likewise, Fox Creek region samples showed correlations between concentrations of Cl and Ca, Na and Ca, and Na and Mg, but these correlations were not seen in the Three Hills region samples. Geochemical modeling demonstrates that there are potential scales formed in the flowback water, but most of the minerals are still in the dissolution state in the formation. Stable isotopic analysis confirmed the mixing of injection water and the formation water.
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Jacobs, Timothy, and Jacob Hedrick. PR-457-14201-R03 Variable NG Composition Effects in LB 2S Compressor Engines - Prediction Enhancement. Pipeline Research Council International, Inc. (PRCI), 2017. http://dx.doi.org/10.55274/r0011406.
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Phase II of the project has focused on improving the initial analysis performed in the first phase by enhancing the various aspects of predictive combustion for lean burn spark ignition natural gas engines under variable composition fueling. These enhancements have incorporated validation data from a Cooper-Bessemer GMVH-10C3 engine located in New Jersey, which improves upon the lack of field data to bound the scope of composition variation. In simulation related endeavors, effort was made to improve the fundamental combustion physics related parameters, namely laminar flame speed, by developing a code base for distributed computing of the chemical kinetics solver, Cantera, and was key to improving upon the chemistry modeling used in the previous phase. Methods to improve numerical convergence were employed to reduce the time to solve large mechanisms, such as the Saudi Aramco Mechanism (v1.3). Modeling of pre-chamber combustion from first principles, common input experimental heat release analysis and simulated heat release generation were additional components of improving model matching with pre-chambered engines. In its current state, manual optimization is required to tune the heat release curves based on guesses about the initial charge mass state, scavenging efficiency, fuel delivery and thereby the trapped equivalence ratio.
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Weiss, W. Jason, Chunyu Qiao, Burkan Isgor, and Jan Olek. Implementing Rapid Durability Measure for Concrete Using Resistivity and Formation Factor. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317120.
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The durability of in-place concrete is a high priority issue for concrete pavements and bridges. Several studies have been conducted by INDOT to use electrical resistivity as a measure of fluid transport properties. Resistivity is dependent on the chemistry of the cement and supplementary cementitious system used, as such it has been recommended that rather than specifying resistivity it may be more general to specify the formation factor. Samples were tested to establish the current levels of performance for concrete pavements in the state of Indiana. Temperature and moisture corrections are presented and acceptable accelerated aging procedure is presented. A standardized testing procedure was developed (AASHTO TP 119–Option A) resulting in part from this study that provides specific sample conditioning approaches to address pore solution composition, moisture conditioning, and testing procedures. An accelerated aging procedure is discussed to obtain later age properties (91 days) after only 28 days.
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Brenan, J. M., K. Woods, J. E. Mungall, and R. Weston. Origin of chromitites in the Esker Intrusive Complex, Ring of Fire Intrusive Suite, as revealed by chromite trace element chemistry and simple crystallization models. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328981.
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To better constrain the origin of the chromitites associated with the Esker Intrusive Complex (EIC) of the Ring of Fire Intrusive Suite (RoFIS), a total of 50 chromite-bearing samples from the Black Thor, Big Daddy, Blackbird, and Black Label chromite deposits have been analysed for major and trace elements. The samples represent three textural groups, as defined by the relative abundance of cumulate silicate phases and chromite. To provide deposit-specific partition coefficients for modeling, we also report on the results of laboratory experiments to measure olivine- and chromite-melt partitioning of V and Ga, which are two elements readily detectable in the chromites analysed. Comparison of the Cr/Cr+Al and Fe/Fe+Mg of the EIC chromites and compositions from previous experimental studies indicates overlap in Cr/Cr+Al between the natural samples and experiments done at &amp;gt;1400oC, but significant offset of the natural samples to higher Fe/Fe+Mg. This is interpreted to be the result of subsolidus Fe-Mg exchange between chromite and the silicate matrix. However, little change in Cr/Cr+Al from magmatic values, owing to the lack of an exchangeable reservoir for these elements. A comparison of the composition of the EIC chromites and a subset of samples from other tectonic settings reveals a strong similarity to chromites from the similarly-aged Munro Township komatiites. Partition coefficients for V and Ga are consistent with past results in that both elements are compatible in chromite (DV = 2-4; DGa ~ 3), and incompatible in olivine (DV = 0.01-0.14; DGa ~ 0.02), with values for V increasing with decreasing fO2. Simple fractional crystallization models that use these partition coefficients are developed that monitor the change in element behaviour based on the relative proportions of olivine to chromite in the crystallizing assemblage; from 'normal' cotectic proportions involving predominantly olivine, to chromite-only crystallization. Comparison of models to the natural chromite V-Ga array suggests that the overall positive correlation between these two elements is consistent with chromite formed from a Munro Township-like komatiitic magma crystallizing olivine and chromite in 'normal' cotectic proportions, with no evidence of the strong depletion in these elements expected for chromite-only crystallization. The V-Ga array can be explained if the initial magma responsible for chromite formation is slightly reduced with respect to the FMQ oxygen buffer (~FMQ- 0.5), and has assimilated up to ~20% of wall-rock banded iron formation or granodiorite. Despite the evidence for contamination, results indicate that the EIC chromitites crystallized from 'normal' cotectic proportions of olivine to chromite, and therefore no specific causative link is made between contamination and chromitite formation. Instead, the development of near- monomineralic chromite layers likely involves the preferential removal of olivine relative to chromite by physical segregation during magma flow. As suggested for some other chromitite-forming systems, the specific fluid dynamic regime during magma emplacement may therefore be responsible for crystal sorting and chromite accumulation.
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McLuckey, Scott A. High Speed DNA Sequencing by Electrospray and Ion/Ion Chemistry. Office of Scientific and Technical Information (OSTI), 2003. http://dx.doi.org/10.2172/1183476.
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Lemly, Joanna, Lauren Laughlin, and Gabrielle Smith. Inventory of fens and rare fen-indicator plant occurrences at Grand Teton National Park and John D. Rockefeller, Jr. Memorial Parkway. National Park Service, 2025. https://doi.org/10.36967/2313526.
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Fens are groundwater-fed, peat-accumulating wetlands that form where the accumulation of organic material exceeds decomposition. While fens are common at northern latitudes, fens in the Rocky Mountains are relatively rare, small features that support numerous rare plant species. Little is known about fens in Grand Teton National Park (GRTE) and John D. Rockefeller, Jr. Memorial Parkway (JODR). While GRTE and JODR are managed for natural resource preservation and recreation, the parks have a history of other land uses and have seen increasing visitors in recent years. To better manage fen resources in GRTE and JODR, the National Park Service funded the Colorado Natural Heritage Program to create a map of potential fens within GRTE and JODR, visit potential fen polygons to verify their status as fens, and survey for rare fen-indicator plant species. The initial map of fens created in the winter of 2022–23 contained 906 potential fens covering 5,208 acres. Field sampling in the summer of 2023 verified 41 fens and 28 peat-accumulating wetlands. The revised map contained 1,016 acres of confirmed or highly likely fens, which were concentrated at elevations below 2,100 m in specific areas of the parks, including Lower Jackson Lake watershed and most of JODR. One hundred and twenty-seven populations of 23 rare fen-indicator plant species were observed either within or near confirmed fens. Rapid vegetation surveys were conducted in 38 confirmed fens. Most were basin fens, several of which contained floating mats, and seven sites were sloping fens. Vegetation composition was overwhelmingly native and indicative of excellent condition. Most sites were dominated by graminoids, specifically sedge (Carex) species, and some sites also contained willows (Salix spp.) and other low shrubs. Quantitative vegetation sampling was carried out in five sites for more precise estimates of species cover. Water chemistry measurements of pH and specific conductance were collected in the field at most sites, and water chemistry samples were collected at five sites for more detailed lab analysis. Water pH ranged from 4.86–8.65 and specific conductance ranged from 1–1105 µS/cm. Most fens were characterized as rich fens, with some considered poor fens and no sites meeting the water chemistry and vegetation classification of extreme rich fen. GRTE and JODR fens are exceptional resources that support numerous rare species. Management plans for the park units should protect and avoid impacting these special habitats and their species so they remain intact into the future.
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Kingston, A. W., A. Mort, C. Deblonde, and O H Ardakani. Hydrogen sulfide (H2S) distribution in the Triassic Montney Formation of the Western Canadian Sedimentary Basin. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329797.
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The Montney Formation is a highly productive hydrocarbon reservoir with significant reserves of hydrocarbon gases and liquids making it of great economic importance to Canada. However, high concentrations of hydrogen sulfide (H2S) have been encountered during exploration and development that have detrimental effects on environmental, health, and economics of production. H2S is a highly toxic and corrosive gas and therefore it is essential to understand the distribution of H2S within the basin in order to enhance identification of areas with a high risk of encountering elevated H2S concentrations in order to mitigate against potential negative impacts. Gas composition data from Montney wells is routinely collected by operators for submission to provincial regulators and is publicly available. We have combined data from Alberta (AB) and British Columbia (BC) to create a basin-wide database of Montney H2S concentrations. We then used an iterative quality control and quality assurance process to produce a dataset that best represents gas composition in reservoir fluids. This included: 1) designating gas source formation based on directional surveys using a newly developed basin-wide 3D model incorporating AGS's Montney model of Alberta with a model in BC, which removes errors associated with reported formations; 2) removed injection and disposal wells; 3) assessed wells with the 50 highest H2S concentrations to determine if gas composition data is accurate and reflective of reservoir fluid chemistry; and 4) evaluated spatially isolated extreme values to ensure data accuracy and prevent isolated highs from negatively impacting data interpolation. The resulting dataset was then used to calculate statistics for each x, y location to input into the interpolation process. Three interpolations were constructed based on the associated phase classification: H2S in gas, H2S in liquid (C7+), and aqueous H2S. We used Empirical Bayesian Kriging interpolation to generate H2S distribution maps along with a series of model uncertainty maps. These interpolations illustrate that H2S is heterogeneously distributed across the Montney basin. In general, higher concentrations are found in AB compared with BC with the highest concentrations in the Grande Prairie region along with several other isolated region in the southeastern portion of the basin. The interpolations of H2S associated with different phases show broad similarities. Future mapping research will focus on subdividing intra-Montney sub-members plus under- and overlying strata to further our understanding of the role migration plays in H2S distribution within the Montney basin.