Academic literature on the topic 'Spectroscopic. kinetic and mechanistic study'

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Journal articles on the topic "Spectroscopic. kinetic and mechanistic study"

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Orzeł, Łukasz, Maria Oszajca, Justyna Polaczek, Dominika Porębska, Rudi van Eldik, and Grażyna Stochel. "High-Pressure Mechanistic Insight into Bioinorganic NO Chemistry." Molecules 26, no. 16 (August 16, 2021): 4947. http://dx.doi.org/10.3390/molecules26164947.

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Pressure is one of the most important parameters controlling the kinetics of chemical reactions. The ability to combine high-pressure techniques with time-resolved spectroscopy has provided a powerful tool in the study of reaction mechanisms. This review is focused on the supporting role of high-pressure kinetic and spectroscopic methods in the exploration of nitric oxide bioinorganic chemistry. Nitric oxide and other reactive nitrogen species (RNS) are important biological mediators involved in both physiological and pathological processes. Understanding molecular mechanisms of their interactions with redox-active metal/non-metal centers in biological targets, such as cofactors, prosthetic groups, and proteins, is crucial for the improved therapy of various diseases. The present review is an attempt to demonstrate how the application of high-pressure kinetic and spectroscopic methods can add additional information, thus enabling the mechanistic interpretation of various NO bioinorganic reactions.
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Kallesha, Nichhapurada, Ningegowda Prasad, N. Shivakumara, and Kereyagalahally H. Narasimhamurthy. "Oxidation of Cinacalcet Hydrochloride by Chloramine-B in Acid Medium: A Kinetic and Mechanistic Study." Asian Journal of Chemistry 33, no. 9 (2021): 2065–68. http://dx.doi.org/10.14233/ajchem.2021.23292.

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Kinetic and mechanistic study of cinacalcet hydrochloride by chloramine-B (CAB) in HCl medium at 308 K was the aim of this work. Analyzed the reaction at five different temperatures and determined the thermodynamic parameters using Arrhenius plots. The reaction had a stoichiometry of 1:2 and characterized the oxidation product using chromatographic and spectroscopic methods. The rate law is deduced from the marked effects, which were accompanied by plausible mechanisms.
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Wallington, Timothy J., James C. Ball, Ole J. Nielsen, and Elzbieta Bartkiewicz. "Spectroscopic, kinetic and mechanistic study of fluoromethylperoxo radicals in the gas phase at 298 K." Journal of Physical Chemistry 96, no. 3 (February 1992): 1241–46. http://dx.doi.org/10.1021/j100182a041.

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Delbaere, S., J. C. Micheau, J. Berthet, and G. Vermeersch. "Contribution of NMR spectroscopy to the mechanistic understanding of photochromism." International Journal of Photoenergy 6, no. 4 (2004): 151–58. http://dx.doi.org/10.1155/s1110662x04000194.

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Along with classical UV-Visible spectroscopy allowing for the determination of intrinsic properties(λmax,ε), multinuclear NMR spectroscopy is a promising and useful tool for studying photochromic reactions. UV irradiation of the initial structure leads to the formation of photoproducts, which can be structurally identified by 1D and 2D NMR experiments. The kinetics of thermal back reaction are monitored by directly and separately measuring the concentrations of each long-living species at regular time intervals in NMR spectra. A plausible reaction mechanism can therefore be proposed. Based on this mechanism, the kinetic analysis and the study of the effects of temperature lead to the determination of the kinetic and thermodynamic parameters (rate coefficients, enthalpy and entropy of activation) of the photochromic system under investigation. This process has been applied to several photochromic families, spirooxazines and benzo- and naphtho-pyrans.
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Sultan, Salah M., and Edmund Bishop. "Mechanistic study and kinetic determination of vitamin C." Journal of Pharmaceutical and Biomedical Analysis 8, no. 4 (January 1990): 345–51. http://dx.doi.org/10.1016/0731-7085(90)80048-t.

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Kallesha N, Prasad N, Mahadeva Swamy M, and Gnanendra C.R. "The kinetic and mechanistic study of levetiracetam oxidation with chloramine-B in acid medium." World Journal of Biology Pharmacy and Health Sciences 13, no. 1 (January 30, 2023): 331–38. http://dx.doi.org/10.30574/wjbphs.2023.13.1.0041.

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The medicine levetiracetam, marketed under the brand name Keppra, is approved by the Food and Drug Administration, used to treat seizures. It belongs to a class of drug known as anticonvulsants. The current work uses sodium-N-chloro-benzene sulfonamide or chloramine-B to evaluate the kinetics and mechanistic of levetiracetam at 308 K in HCl medium. (CAB). The reaction has a first-order dependence on [CAB]0 and [substrate]0, as well as a fractional-order dependence on the concentration of [HCl]. Changes in ionic strength or the adding of benzene sulfonamide have no effect on the rate. We looked at the effect at five temperatures. The Arrhenius plots were used to evaluate the thermodynamic parameters. The reaction stoichiometry was found 1:2, and chromatographic and spectroscopic studies anticipated the oxidation product imine. The probable mechanism back up the above-mentioned findings. The relevant rate law has been determined because of all these discoveries.
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Saifuddin, Md, Suho Kim, Abdul Aziz, and Kwang Soo Kim. "Mechanistic Study of Phosphorus Adsorption onto Iron Z-A: Spectroscopic and Experimental Approach." Applied Sciences 9, no. 22 (November 15, 2019): 4897. http://dx.doi.org/10.3390/app9224897.

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Iron was incorporated into an LTA type zeolite using the sol-gel hydrothermal method to form Iron-zeolite-A (Iron-Z-A), and its phosphate adsorption-desorption efficiency were analyzed. Samples were characterized by EDS, SEM, XRD, EPR, FT-IR XPS, and Raman to ensure the apt synthesis of Iron-Z-A and to interpret the mechanism of adsorption-desorption of PO43− in an aqueous solution. EPR and XPS analysis confirmed that the iron was doped as Fe3+ in the LTA structure. The XPS peak shift (Fe-2p), FT-IR band shift, and intensity change (–OH) confirmed the existence of the ligand exchange mechanism. In the adsorption phase at pH 5, the derivative of phosphate (H2PO4−) acts as a ligand and interacts with OH of Fe on the zeolite surface to form “Iron-zeolite (oxy) hydroxide bound phosphate”. In the desorption phase at pH 10, phosphate ligand is detached and get mixed in the aqueous phase as HPO42−. The EDS data, Si–O–Al band shift and intensity change in FT-IR and XPS peak intensity change proved the contribution of Al in the process of adsorption. The data of adsorption fitted well with the Langmuir’s isotherm and pseudo-second-order kinetic model. The amount of PO43− adsorbed was a function of adsorbent’s surface area regardless of concentration. The amount of PO43− being adsorbed by the metal ions was found to be 382.296 mg PO43−/g Fe and 56.296 mg PO43−/g Al.
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Tellers, David M., and Robert G. Bergman. "Mechanistic study of ligand substitution processes in TpIr(III) complexes." Canadian Journal of Chemistry 79, no. 5-6 (May 1, 2001): 525–28. http://dx.doi.org/10.1139/v00-162.

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The synthesis of the cationic hydridotris(pyrazolyl)borate iridium(III) complex [Tp(PMe3)IrMe(ClCH2Cl)][BArf] (2-CH2Cl2) is reported. Spectroscopic characterization of 2-CH2Cl2 in CH2Cl2 solution indicates that exchange of bound CH2Cl2 with free CH2Cl2 is slow on the NMR time scale. Under 50 atm (1 atm = 101.325 kPa) of N2, the CH2Cl2 in 2-CH2Cl2 is displaced by N2 to yield [Tp(PMe3)IrMe(N2)][BArf] (2-N2). The stronger nucleophile CH3CN reacts rapidly with 2-CH2Cl2 to produce [Tp(PMe3)IrMe(NCCH3)][BArf] (4). A kinetic study was performed on CH2Cl2 substitution in 2-CH2Cl2 by CD3CN. The data are most consistent with dissociative loss of CH2Cl2 to generate the unsaturated species ([Tp(PMe3)IrMe][BArf]) which then reacts with CD3CN to generate [Tp(PMe3)IrMe(NCCD3)][BArf]. Further evidence for a dissociative mechanism was obtained by comparison of ligand substitution rates for the Tp complexes with the analogous TpMe2 complexes (TpMe2 = hydridotris(3,5-dimethylpyrazolyl)borate). The relevance of these substitution experiments to C—H activation by cationic iridium(III) complexes is discussed.Key words: iridium, hydridotris(pyrazolyl)borate, methylene chloride and dinitrogen complexes, dissociative substitution.
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Cho, Hyejin, and Wansik Cha. "Rapid Hydrolysis of Organophosphates Induced by U(IV) Nanoparticles: A Kinetic and Mechanistic Study using Spectroscopic Analysis." Colloids and Interfaces 3, no. 4 (November 26, 2019): 63. http://dx.doi.org/10.3390/colloids3040063.

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The heterogeneous interactions of colloidal U particles with organophosphates, leading to the formation of U-phosphate minerals, can retard the migration of U in contaminated sites. Here, we studied the hydrolytic mechanism of p-nitrophenyl phosphate (NPP) on the surfaces of tetravalent uranium nanoparticles (U(IV)NPs), resulting in the formation of U-phosphate precipitates. Our study shows that the reaction rate of NPP hydrolysis is significantly enhanced by U(IV)NPs through a multi-step heterogeneous reaction on the particle surfaces. The end products of the reaction were identified as U(IV)NPs-aggregates with surface-bound phosphates. Colloidal properties, such as high positive values of the zeta-potential (>+30 mV) and large surface areas of U(IV)NPs due to their unique cluster structures consisting of relatively small primary UO2(cr)-particles, are correlated with their reactivity towards hydrolysis reaction. Reaction kinetic modeling studies using spectrophotometric data indicated the presence of two distinct reaction intermediates as the surface complexes of NPP on U(IV)NPs. We suggest the involvement of the NPP inner-sphere complexes in the rate-determining step based on the results obtained by analyzing the ATR-FTIR spectra and the surface-enhanced infrared absorption of NPP bound to substrate surfaces.
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Iuga, Cristina, C. Ignacio Sainz-Díaz, and Annik Vivier-Bunge. "Hydroxyl radical initiated oxidation of formic acid on mineral aerosols surface: a mechanistic, kinetic and spectroscopic study." Environmental Chemistry 12, no. 2 (2015): 236. http://dx.doi.org/10.1071/en14138.

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Environmental context The presence of air-borne mineral dust containing silicates in atmospheric aerosols should be considered in any exploration of volatile organic compound chemistry. This work reports the mechanisms, relative energies and kinetics of free-radical reactions with formic acid adsorbed on silicate surface models. We find that silicate surfaces are more likely to act as a trap for organic radicals than to have a catalytic effect on their reactions. Abstract Heterogeneous reactions of atmospheric volatile organic compounds on aerosol particles may play an important role in atmospheric chemistry. Silicate particles are present in air-borne mineral dust in atmospheric aerosols, and radical reactions can be different in the presence of these mineral particles. In this work, we use quantum-mechanical calculations and computational kinetics to explore the reaction of a hydroxyl free radical with a formic acid molecule previously adsorbed on several models of silicate surfaces. We find that the reaction is slower and takes place according to a mechanism that is different than the one in the gas phase. It is especially interesting to note that the reaction final products, which are the formyl radical attached to the cluster surface, and a water molecule, are much more stable than those formed in the gas phase, the overall reaction being highly exothermic in the presence of the surface model. This suggests that the silicate surface is a good trap for the formed formyl radical. In addition, we have noted that, if a second hydroxyl radical approaches the adsorbed formyl radical, the formation of carbonic acid on the silicate surface is a highly exothermic and exergonic process. The carbonic acid molecule remains strongly attached to the surface, thus blocking CO2 formation in the formic acid oxidation reaction. The spectroscopic properties of the systems involved in the reaction have been calculated, and interesting frequency shifts have been identified in the main vibration modes.
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Dissertations / Theses on the topic "Spectroscopic. kinetic and mechanistic study"

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Silver, Sunshine Christine. "Kinetic, mechanistic and spectroscopic studies of spore photoproduct lyase." Diss., Montana State University, 2010. http://etd.lib.montana.edu/etd/2010/silver/SilverS1210.pdf.

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Spore forming organisms are a health threat to humans and other animals in part due to a remarkable resistance to UV irradiation. This resistance results from two events: first, the formation of a unique thymine dimer, 5-thyminyl-5,6-dihydrothymine (spore photoproduct, or SP) upon UV irradiation; and more importantly, the rapid and specific repair of this DNA photoproduct to two thymines by spore photoproduct lyase (SP lyase). Understanding the molecular basis of this radical-mediated DNA repair will ultimately allow for a better understanding of how to address the health risks caused by spore forming bacteria. SP lyase requires S-adenosyl-L-methionine and a [4Fe-4S]¹+/²+ cluster to perform its catalysis. Presented in this work is a characterization of Clostridium acetobutylicm SP lyase and its ability to repair stereochemically defined dinucleoside and dinucleotide synthetic substrates. Careful synthesis and characterization followed by assays monitored by HPLC indicate SP lyase repairs only the 5R isomer of SP with an activity of 0.4 nmol/min/mg (dinucleoside substrate) and 7.1 nmol/min/mg (dinucleotide substrate). These results support the longstanding theory of SP formation by dimerization of adjacent thymines in double-helical DNA. Kinetic and mechanistic studies were pursued to further elucidate the mechanism of SP repair. Upon pre-reducing SP lyase, the specific activity increased nearly 4-fold to 1.29 μmol/min/mg. Mechanistic studies utilizing [C-6-³H] SP DNA as the substrate revealed a primary tritium kinetic isotope effect of 16.1, indicating a rate determining step during the repair reaction. These results suggest nonstereospecific SP formation regarding the C-6 position and subsequent stereospecific abstraction of the C-6 H atom by SP lyase. Mossbauer and Fe/S K-edge X-ray absorption studies of anaerobically prepared SP lyase aided in further characterization of the [4Fe-4S] cluster and its interaction with SAM. The Fe K-edge EXAFS provide evidence for a slight cluster distortion upon interacting with SAM as a new spectral feature indicative of longer Fe-Fe distances is observed. The Fe K-edge XANES provide further support that SAM is not undergoing reductive cleavage in the presence of reduced SP lyase. Our XAS studies may provide new insights into the mechanism by which radical SAM enzymes initiate their diverse catalysis. 'Co-authored by Tilak Chandra, Egidijus Zilinskas, Eric M. Shepard, William E. Broderick, Joan B. Broderick, Shourjo Ghose, Jeffrey M. Buis, David J. Gardenghi, BoiHanh Huynh, and Robert K. Szilagyi.'
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Gómez, Martín Juan Carlos. "Spectroscopic, kinetic and mechanistic studies of atmospherically relevant I2-O3 photochemistry." Berlin Logos-Verl, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2927252&prov=M&dok_var=1&dok_ext=htm.

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Gómez, Martín Juan Carlos. "Spectroscopic, kinetic and mechanistic studies of atmospherically relevant I2/O3 photochemistry /." Berlin : Logos-Verl, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2927252&prov=M&dok_var=1&dok_ext=htm.

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Whyte, Lynden J. "A kinetic and mechanistic study of tropospheric reactions." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314391.

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El-Agez, Bassam Ali. "A kinetic and spectroscopic study on cytochrome c oxidase." Thesis, University of Essex, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305116.

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Kalinga, Shivashankar. "Peroxynitrite-induced modifications of myoglobin : a kinetic and mechanistic study /." Zürich : ETH, 2005. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16014.

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Siu, Tung. "Kinetic and mechanistic study of aqueous sulfide-sulfite-thiosulfate system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0007/MQ45585.pdf.

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Scott, Laura-Marie. "Kinetic and mechanistic study of Lilestralis, a synthetic muguet fragrance molecule." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=165414.

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In the multi-step synthesis of Lilestralis, a synthetic muguet fragrance, the kinetics and mechanism of the formation of 3-(3-t-butylphenyl)-2-methylpropan-1-ol (m-LOL) and 4-(3-t-butylphenyl)-2-methylpropan-1-ol (p-LOL) from 2-methyl-3-phenylpropan-1-ol (MPP) and isobutylene using concentrated liquid phosphoric acid as a catalyst was investigated. By-products that include phosphate esters of MPP, m-LOL and p-LOL and oligomers of isobutylene were produced during this reaction and their role within the kinetics and mechanism was also investigated. When crystalline phosphoric acid is dissolved in water, it can form equilibrium polyphosphate mixtures at high acid concentrations. The phosphate species have the general formula Hn+2PnO3n+1 and consist of species such as orthophosphoric acid (H3PO4), pyrophosphoric acid (H4P2O7) and triphosphoric acid (H5P3010). The presence of polyphosphate within liquid phosphoric acid solutions used in this study was investigated using 31P NMR. To investigate the influence of water on the reaction, a number of experiments were performed using 1,4-dioxane as a solvent. This was chosen as the boiling points and density are similar to water, although it is classified as an aprotic solvent. Phosphate esters of MPP, m-LOL and p-LOL are produced as by-products and can potentially undergo hydrolysis when water is present, therefore reactions using aqueous phosphoric acid solutions may not give a true reflection of the concentration of phosphate esters produced. The use of heterogeneous catalysts was also investigated in order to improve yield and selectivity for p-LOL and m-LOL. These include acid catalysts such as solid phosphoric acid supported on Kieselguhr (SPA), sulphated zirconia and ultra stable zeolite-Y (H-USY).
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Souza, Valdir Araujo de. "Corrosion and erosion-corrosion of wc-based cermet coatings - a kinetic and mechanistic study." Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/318.

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Fakih, Mariam. "Réactivité atmosphérique des principaux produits d'oxydation de première génération des monoterpènes." Electronic Thesis or Diss., Reims, 2024. http://www.theses.fr/2024REIMS010.

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Les monoterpènes sont des composés organiques volatils biogéniques (COVB) largement émis dans l'atmosphère par les forêts et les cultures végétales, représentant ainsi des acteurs significatifs de la chimie atmosphérique. Leur réactivité importante envers les oxydants atmosphériques a fait sujet de plusieurs études dans la littérature. Cependant, leurs produits de première génération d’oxydation sont moins évalués et pourraient expliquer en partie la réactivité manquante ainsi que la sous-estimation de la formation des AOS par les modèles. Dans ce contexte, cette étude vise à comprendre la réactivité atmosphérique de cinq COVB (nopinone, myrténal, kétolimonène, caronaldéhyde, et limononaldéhyde) qui sont des produits de première génération de l’oxydation des α et β-pinène et du limonène. Ce travail porte sur l’étude des processus de dégradation en déterminant la cinétique et le mécanisme des réactions d'oxydation des COVB visés par le radical OH, le chlore et l’ozone, ainsi que leur potentielle de photolyse au travers de l’étude de leurs spectres d’absorption UV-Vis. Pour ce faire, les réactions d'oxydation des cinq produits de première génération d’oxydation de monoterpènes ont été étudiées en chambre de simulation atmosphérique couplée à différentes techniques analytiques (FTIR, SPME-GC/MS, PTR-MS-ToF).L’étude spectroscopique se concentre sur la détermination des spectres d’absorption UV-visible des cinq composés dans le domaine 200-400 nm à une température de 353 ± 2 K, et à une pression inférieure à la pression de vapeur saturante du COVB. Les spectres montrent une large bande d'absorption située entre 240 et 370 nm, correspondant à la bande n-π* du groupement carbonyle. L'absorption significative de ces composés au-delà de 290 nm suggère qu’ils sont susceptibles d'être décomposés par photolyse en quelques heures au minimum.Les études cinétiques en température réalisées dans cette thèse concernent la réaction (COV+ OH) pour le nopinone, le myrténal, le kétolimonène et le limononaldehdye, la réaction (COV + Cl) pour le nopinone, le myrténal et le kétolimonène et la réaction d’ozonolyse pour le kétolimonène, le myrténal et le limononaldéhyde. Les expériences ont été menées soit en utilisant la méthode cinétique relative ou la méthode cinétique absolue dans le domaine de température 298 – 353 K et à pression atmosphérique. Les résultats cinétiques obtenus ont permis de calculer les durées de vie atmosphérique de ces composés. Leur persistance atmosphérique ne dépasse pas une journée. Ces durées de vie montrent globalement que la principale voie d’élimination des composés étudiés est liée à leur réaction avec les radicaux OH avec une concurrence importante en région côtière des radicaux Cl. Par ailleurs, les études cinétiques en température ont mis en évidence une tendance générale positive avec l'augmentation de la température vis à vis des radicaux OH et de l’ozone et négative avec le chlore.Enfin des études mécanistiques d’ozonolyse concernant l’ozonolyse du kétolimonène, myrténal et limononaldéhyde ont été élaborées. Ces études consistent à suivre l’évolution temporelle des réactifs ainsi que leur produit de formation. Ces données nous ont permis d’extraire le taux de formation des produits formés lors des processus d’ozonolyse. En se basant sur ces résultats des mécanismes réactionnels d’ozonolyse du kétolimonène, myrténal et limononaldéhyde sont proposés
Monoterpenes are biogenic volatile organic compounds (BVOCs) widely emitted into the atmosphere by forests and plant crops, thus representing significant players in atmospheric chemistry. Their high reactivity towards atmospheric oxidants has been the subject of several studies in the literature. However, their first-generation oxidation products are less evaluated, and could partly explain the missing reactivity and the underestimation of AOS formation by models. In this context, this study aims to understand the atmospheric reactivity of five VOCBs (nopinone, myrtenal, ketolimonene, caronaldehyde, and limononaldehyde) that are first-generation oxidation products of α- and β-pinene and limonene. This work focuses on the study of degradation processes by determining the kinetics and mechanism of oxidation reactions of the targeted BVOCs by the OH radical, chlorine and ozone, as well as their potential photolysis through the study of their UV-Vis absorption spectra. To this end, the oxidation reactions of five first-generation monoterpene oxidation products were studied in an atmospheric simulation chamber coupled with various analytical techniques (FTIR, SPME-GC/MS, PTR-MS-ToF).The spectroscopic study focused on determining the UV-visible absorption spectra of the five compounds in the 200-400 nm range at a temperature of 353 ± 2 K, and at a pressure below the saturation vapor pressure of COVB. The spectra show a broad absorption band between 240 and 370 nm, corresponding to the n-π* band of the carbonyl group. The significant absorption of these compounds above 290 nm suggests that they are likely to be removed by photolysis in at least a few hours.The temperature kinetic studies carried out in this thesis concern the (VOC+ OH) reaction for nopinone, myrtenal, ketolimonene and limononaldehdye, the (VOC + Cl) reaction for nopinone, myrtenal and ketolimonene and the ozonolysis reaction for ketolimonene, myrtenal and limononaldehyde. Experiments were carried out using either the relative or the absolute kinetic method in the temperature range 298 - 353 K and at atmospheric pressure. The kinetic results obtained made it possible to calculate the atmospheric lifetimes of these compounds. Their atmospheric persistence does not exceed one day. Overall, these lifetimes show that the main route of elimination for the compounds studied is through their reaction with OH radicals, with significant competition in coastal regions from Cl radicals. The study also revealed a generally positive trend for OH radicals and ozone with increasing temperature, and a negative trend for chlorine.Finally, mechanistic ozonolysis studies of ketolimonene, myrtenal and limononaldehyde were carried out. These studies consist of monitoring the temporal evolution of the reagents as well as the reaction product. These data allowed us to extract the formation rate of the products formed during ozonolysis processes. Based on these results, reaction mechanisms of ozonolysis of ketolimonene, myrtenal and limononaldehyde are proposed
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Books on the topic "Spectroscopic. kinetic and mechanistic study"

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Whyte, Lynden J. A kinetic and mechanistic study of tropospheric reactions. Norwich: University of East Anglia, 1989.

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Siu, Tung. Kinetic and mechanistic study of aqueous sulfide-sulfite-thiosulfate system. Ottawa: National Library of Canada, 1999.

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Farrokhnia, A. Kinetic and mechanistic study of the reaction of chlorofluoromethanes and hydrochlorofluoromethanes with prefluorided chromia catalyst. Manchester: UMIST, 1998.

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Rim, Guanhe. Coupled Kinetic and Mechanistic Study of Carbonation of Silicate Materials with Tailored Transport Behaviors for CO2 Utilization. [New York, N.Y.?]: [publisher not identified], 2020.

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Muk, Hwang Soon, DeWitt Kenneth J, and United States. National Aeronautics and Space Administration., eds. High temperature kinetic study of the reactions H + O₂ = OH + O and O + H₂ = OH + H in H₂/O₂ system by shock tube - laser absorption spectroscopy. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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Book chapters on the topic "Spectroscopic. kinetic and mechanistic study"

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Stickel, R. E., J. M. Nicovich, S. Wang, Z. Zhao, and P. H. Wine. "Kinetic and Mechanistic Study of the Reaction of Atomic Chlorine with Dimethylsulfide." In Dimethylsulphide: Oceans, Atmosphere and Climate, 243–49. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-017-1261-3_25.

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Hynes, A. J., and P. H. Wine. "Direct Kinetic and Mechanistic Study of the OH—Dimethyl Sulfide Reaction Under Atmospheric Conditions." In ACS Symposium Series, 133–41. Washington, DC: American Chemical Society, 1987. http://dx.doi.org/10.1021/bk-1987-0349.ch011.

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Roberts, G. C. K., and L. Y. Lian. "NMR Approaches To Understanding Protein Specificity." In Biological NMR Spectroscopy. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195094688.003.0015.

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The biological functions of proteins all depend on their highly specific interactions with other molecules, and the understanding of the molecular basis of the specificity of these interactions is an important part of the effort to understand protein structure-function relationships. NMR spectroscopy can provide information on many different aspects of protein-ligand interactions, ranging from the determination of the complete structure of a protein-ligand complex to focussing on selected features of the interactions between the ligand and protein by using “reporter groups” on the ligand or the protein. It has two particular advantages: the ability to study the complex in solution, and the ability to provide not only structural, but also dynamic, kinetic and thermodynamic information on ligand binding. Early analyses of ligand binding (Jardetzky and Roberts, 1981) focused on measurements of relaxation times, chemical shifts and coupling constants, which gave relatively limited, although valuable, structural information. More recently, it has become possible to obtain much more detailed information, due to the extensive use of nuclear Overhauser effect measurements and isotope-labeled proteins and ligands; a number of reviews of this area are available (Feeney and Birdsall, 1993; Lian et al, 1994; Wand and Short, 1994; Petros and Fesik, 1994; Wemmer and Williams, 1994). In this article, we describe some recent work from our laboratory which illustrates the use of NMR spectroscopy to obtain structural and mechanistic information on relatively large enzyme-substrate and proteinprotein complexes. A number of species of pathogenic bacteria, notably Streptococci and Staphylococci, have proteins on their surface that bind immurioglobulins (reviewed in Boyle (1990)). Protein A from S. aureus and protein G from species of Streptococci are widely used as imrnunological tools and are the most extensively studied of these antibody-binding proteins. A detailed understanding of the binding mechanisms of these proteins is important, not only for providing us with the structural basis for their functions, but also as a contribution toward understanding the general rules of protein-protein interactions.
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Bortiatynski, Jacqueline M., and Patrick G. Hatcher. "The Development of 13C Labeling and 13C NMR Spectroscopy Techniques to Study the Interaction of Pollutants with Humic Substances." In Nuclear Magnetic Resonance Spectroscopy in Environment Chemistry. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195097511.003.0007.

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Modern agricultural practices have contributed to the accumulation of herbicides, pesticides and their decomposition products in the soil. These pollutants are known to interact with soil organic matter to form covalent and/or noncovalent bonding associations. The covalent bonds are thought to result from addition or oxidative coupling reactions, some of which may be catalyzed by oxidoreductive enzymes. Noncovalent associations include such interactions as ion exchange, hydrogen bonding, protonation, charge transfer, ligand exchange, coordination through metal ions, van der Waals forces, and hydrophobic bonding. The association of pollutants with soil organic matter is an area of study that is of extreme interest for two reasons. First, dissolved organic matter present in lakes and streams is known to enhance the solubility of pollutants, which poses a real threat to the quality of fresh water supplies. Therefore, if we are to predict the movement of pollutants in the water table we need to have a mechanistic understanding of their interactions with dissolved humic materials. Second, early studies had indicated that some pollutants chemically bind to humic materials, thus reducing the risk of further transport and dispersion. If this chemical binding of the pollutants is irreversible, then this process may serve as a natural means for their detoxification. Regardless of the type of association, the first task in any mechanistic study is to characterize the reaction products structurally. In the case of noncovalent binding mechanisms, studies have focused on the physical characteristics of the process and not on the structure of the associated pollutant. Association studies are used to determine the sorption kinetics and transport of pollutants as well as their association constants. These types of studies utilize various techniques such as batch sorption, gas-purge desorption, column adsorption, and miscible displacement. All of these techniques are only capable of providing quantitative information on the amount of pollutant sorbed by a substrate. The study of the covalent binding of pollutants to humic substances has utilized 14C labeling in addition to various spectrometric techniques such as ultraviolet (UV) difference, fluorescence polarization and infrared (IR) spectroscopy.
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Oyama, S. Ted, Corey Reed, Yong-Kul Lee, and Yan Xi. "True Intermediates and Spectators in Reaction Mechanisms: A Kinetic and Spectroscopic Study." In Science and Technology in Catalysis 2006, 103–8. Elsevier, 2007. http://dx.doi.org/10.1016/b978-0-444-53202-2.50016-6.

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Pantazidis, A., and C. Mirodatos. "Mechanistic approach of the oxidative dehydrogenation of propane over VMgO catalysts by in situ spectroscopic and kinetic techniques." In 11th International Congress On Catalysis - 40th Anniversary, Proceedings of the 11th ICC, 1029–38. Elsevier, 1996. http://dx.doi.org/10.1016/s0167-2991(96)80314-4.

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Arena, F., F. Frusteri, A. Mezzapica, and A. Parmaliana. "Kinetic and mechanistic study of the partial oxidation of methane to formaldehyde on silica catalyst." In Studies in Surface Science and Catalysis, 3585–90. Elsevier, 2000. http://dx.doi.org/10.1016/s0167-2991(00)80579-0.

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Rajalakshmi, K. "Kinetic and Mechanistic Study of Oxidation of Chalcones by Morpholinium Chlorochromate with Oxalic Acid as Catalyst." In Challenges and Advances in Chemical Science Vol. 8, 52–58. Book Publisher International (a part of SCIENCEDOMAIN International), 2022. http://dx.doi.org/10.9734/bpi/cacs/v8/4409d.

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Ángel de Carvalho Servia, Miguel, and Ehecatl Antonio del Rio Chanona. "Interpretable Machine Learning for Kinetic Rate Model Discovery." In Machine Learning and Hybrid Modelling for Reaction Engineering, 133–58. Royal Society of Chemistry, 2023. http://dx.doi.org/10.1039/bk9781837670178-00135.

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Due to global scale problems (e.g. exponential population growth), catalytic processes are of more importance today than they have ever been before. The industrialisation of these processes requires kinetic models. Mechanistic models are difficult to construct; data-driven and hybrid models, although easier to construct, lack interpretability and physical knowledge. Recently, a new approach called automated knowledge discovery has been popularised, but existing methods in the literature suffer from important drawbacks: necessitating assumptions about model structures and a lack of model selection routine (both being directly linked to kinetic model building). As such, this motivated the presented work to construct a generalisable methodological framework for the automated discovery of catalytic kinetic models. The methodological framework proposed utilises symbolic regression for model generation, a hybrid optimisation algorithm for parameter estimation, and the Akaike information criterion (AIC) and the Hunter–Reiner criterion for model selection and discrimination, respectively. The methodology was applied to an illustrative isomerisation case study, where concentration versus time data were provided for three different experiments (i.e. each experiment has different initial conditions). The framework was able to retrieve the correct kinetic model with realistic (i.e. noisy) data from the catalytic system. This exemplifies how the presented methodology can be harnessed to efficiently provide important and interpretable insights of catalytical systems that have not yet been researched.
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Vega-Ramon, Fernando, Wei Wang, Wei Wu, and Dongda Zhang. "Reaction Network Simulation and Model Reduction." In Machine Learning and Hybrid Modelling for Reaction Engineering, 182–207. Royal Society of Chemistry, 2023. http://dx.doi.org/10.1039/bk9781837670178-00182.

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Modelling and simulation of reaction networks is a challenging task that aims to decode the inherent kinetic characteristics of complex (bio)chemical reactions. In this chapter, a heterogeneous catalysis case study is adopted to elucidate the step-by-step derivation of a microkinetic model for a given reaction network. Subsequently, the use of physics- and mathematics-based network reduction strategies is exemplified to identify kinetically negligible elementary steps in the proposed mechanism. In the physics-based approach, the ratios of the fitted microkinetic rate constants are evaluated against a threshold to identify irreversible reactions, whereas in the mathematics-based approach an additional penalty term is introduced during microkinetic parameter estimation to penalise the number of active chemical pathways. Finally, the construction of traditional steady-state models for the reduced networks is also demonstrated through the application of the pseudo-steady-state hypothesis to the reaction intermediates. The underlying physical meaning of the proposed model structures and their parameters are discussed throughout to illustrate the role of kinetic model interpretability in the development of process mechanistic understanding.
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Conference papers on the topic "Spectroscopic. kinetic and mechanistic study"

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Ahubelem, N., M. Altarawneh, and B. Z. Dlugogorski. "Kinetic and Mechanistic Study into Emission of HCl in Fires of PVC." In Proceedings of the Seventh International Seminar Fire and Explosion Hazards. Singapore: Research Publishing Services, 2013. http://dx.doi.org/10.3850/978-981-07-5936-0_06-04.

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Andrews, J. W., Y. Z. Hu, and E. A. Irene. "In-Situ Spectroscopic Ellipsometry Investigation Of Ion Beam Damage: A Kinetic Study." In 1989 Microelectronic Intergrated Processing Conferences, edited by Robert S. Freund. SPIE, 1990. http://dx.doi.org/10.1117/12.963950.

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Asha, P. K. "Spectroscopic approach for the oxidation of an anesthetic agent etomidate using potassium permanganate–a kinetic study." In NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020. AIP Publishing, 2021. http://dx.doi.org/10.1063/5.0061277.

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FAKIh, Mariam. "Gas-phase kinetic and mechanistic study of degradation of a several of first-generation oxidation products of monoterpene by Ozone." In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.13876.

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Zhang, Kaiyi, and Guan Qin. "Mechanistic and Kinetic Study of CO2-CH4 Exchange Process in Methane Hydrates Using Molecular Dynamics Simulation." In SPE Europec featured at 81st EAGE Conference and Exhibition. Society of Petroleum Engineers, 2019. http://dx.doi.org/10.2118/195457-ms.

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Yucel, Umut, and Emelie Ivarson. "Analysis of lipid radiolysis in irradiated dried meat products." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/apmz8310.

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Irradiation is a non-thermal process used for preservation and decontamination of human and animal food products. Although irradiation process causes minimal changes to the sensory and nutritional quality, certain irradiation-specific compounds form, such as free radicals and related lipid radiolysis products, which can have organoleptic and health concerns, especially at high doses of 50 kGy or more. For example, radiolysis of palmitic acid-containing lipids typically results in the formation of a unique irradiation marker 2-dodecylcyclobutanone (2-DCB) along with other hydrocarbons (tridecane, 1-tetradecene, tetradecane, 1-pentadecene). Analysis of these irradiation-specific molecules can also be used to back-trace irradiation history of the products. This study involves with the quantitative and mechanistic analysis of the lipid radiolysis products in parallel to changes in the amount of precursor lipid molecules in two dried meat matrixes (e.g., chicken jerkies and pig ears) using SPME-coupled GC-MS analysis. Overall, the formation of rate if 2-DCB was higher (p < 0.05) than hydrocarbons both following zero order kinetics; whereas, the decrease in precursor fatty acids followed first order kinetics. The quantitative analysis requires the use of a suitable internal standard (IS), which can interact with the extraction of the analyte (e.g., 2-DCB) below a critical concentration. This critical concertation was an order of magnitude large in pig ears (>80 ppb) than chicken jerkies (>8 ppb) in parallel to the amount of precursor lipid. Finally, electron paramagnetic resonance spectroscopy was employed complementary to GC-MS analysis, however, providing confirmatory information. The findings of this research help to elucidate the irradiation-specific changes in irradiated meat matrices using an analytical method that also allows quantitative analysis of small sample volumes.
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Pfaendtner, Jim, Linda J. Broadbelt, and Q. Jane Wang. "Strategies for Constructing Reaction Networks of Lubricant Degradation." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-64008.

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Automated mechanism generation is an essential tool to be able to create mechanistic models of lubricant degradation chemistry. To date, modeling of lubricant degradation has been accomplished only through the use of lumped or pathways-style approaches. These methods have yielded important insights into major degradation pathways but lack predictive power and fail to produce some key trends in the product distribution, even qualitatively. Mechanistic models of lubricant degradation include reactivity of individual species as well as the role of secondary reactions. Such models have much to offer in terms of fundamental understanding of degradation chemistry. Furthermore, they may be exploited to directly study the effect of radical stabilizers and additives. Key results obtained include a quantitative description of the degradation of a model lubricant as well as detailed kinetic correlations for estimating rate constants. This poster presents our efforts to construct detailed reaction mechanisms of lubricant degradation. The underlying theories of automated network generation and preliminary results are presented.
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Thominette, F., I. Merdas, and J. Verdu. "Ageing of PA 11 Pipes in CO2 Medium: A Tool to Predict Their Residual Lifetime." In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28054.

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The study of polyamide 11 hydrolysis in acid medium has a great importance taking into account the presence of CO2 pressure in the fields. Experimentally we have put in evidence that CO2 accelerates PA 11 hydrolysis and shift the equilibrium towards high conversions. Theoretically, two mechanisms can be involved in the CO2 effect on hydrolysis: - a catalytic effect by H+ ions (acceleration of the hydrolysis reaction); - an amine scavenging by CO2 (shift of the equilibrium towards high conversion) From this mechanistic scheme we propose a kinetic model. Then, we have built a computer program allowing to made all the calculations needed in practice by the users as the average molar mass and the residual lifetime for given conditions.
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Milanović, Žiko, Edina Avdović, Marko Antonijević, and Zoran Marković. "DIRECT SCAVENGING ACTIVITY OF 4,7-DIHYDROXYCOUMARIN DERIVATIVE TOWARDS SERIES OF CHLOROMETHYLPEROXY RADICALS." In 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac,, 2021. http://dx.doi.org/10.46793/iccbi21.462m.

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In this study, the mechanisms of antiradical activity of the previously synthesized 4,7- dihydroxycoumarin derivative:(E)-3-(1-((4-hydroxyphenyl)amino)ethylidene)-2,4- dioxochroman-7-yl acetate (A-4OH) according to the series of chloromethylperoxy radicals: OOCH2Cl (chloromethylperoxy), OOCHCl2 (dichloromethylperoxy) and OOCCl3 (trichloromethyl peroxy) were investigated. To assess the mechanisms of antiradical activity of A-4OH against chloromethylperoxy radicals, the following mechanistic pathways were examined: Hydrogen Atom Transfer (HAT), Single-Electron Transfer followed by Proton Transfer (SET-PT), and Radical Adduct Formation (RAF). The investigations were performed in water using sophisticated computational methods. The results of the study show that the activity against selected radicals decreases in series •OOCCl3 > •OOCHCl2 > •OOCH2Cl. The results of thermodynamic and kinetic parameters indicate that A-4OH inactivates selected radicals via the HAT mechanism.
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Fathy, Ahmed, Anas M. Hassan, Mohammad B. Abdullah, Emad W. Al-Shalabi, Fabio Bordeaux Rego, Mojdeh Delshad, and Kamy Sepehrnoori. "Numerical Study on Tackling Microbial Reservoir Souring During Engineered Water Injection." In SPE Improved Oil Recovery Conference. SPE, 2024. http://dx.doi.org/10.2118/218236-ms.

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Abstract Sulfate-reducing bacteria (SRB) activity in reservoirs causes several challenges related to reservoir souring during waterflooding. Sulfate removal units are utilized as a souring treatment solution; however, these units are expensive, and the discussion becomes more relevant when using engineering water injection (EWI) and its related benefits. In the present study, a biochemical numerical model was developed to capture a laboratory continuous up-flow packed-bed bioreactor testing using suitable microbial growth and metabolite production kinetic models. The capabilities of modeling microbial souring treatments at the laboratory and field scales during EWI were explored in this study. We employed a reservoir simulator model with a fairly simple but metabolically accurate description of competing bacterial kinetic processes. The proposed model captured the detailed mechanistic examinations of SRB and NR-SOB activities in a laboratory bioreactor alongside predicting the impacts of different influential parameters on SRB growth at a field scale model. In the absence of detailed data, the findings appear to be compatible with established characteristics of microbial growth. The results showed that the developed 1D model was successful in history matching the increase in the generated H2S at the end of SRB growth duration in the bioreactor laboratory experiment. Moreover, the treatment was deemed successful since nitrate-reducing sulfide oxidizing bacteria (NR-SOB) commenced to grow as the nitrate was injected gradually. This resulted in complete mitigation of the H2S generated supported by the NR-SOB oxidation equation. The 1D model was tuned by division factor and reaction rate constant to match better the experimental data for H2S and H2SO4 concentrations’ change. For the 3D field-scale model, the findings showed that temperature reduction from mixing between injected and formation waters triggered H2S generation reaction and accumulation at the injector. Subsequently, it was observed that the front was moving till a breakthrough at the injector after almost 5 months where it stabilized for three months and then sharply dropped as most of the volatile fatty acid (VFA) was consumed limiting the further generation of H2S. Furthermore, SRB in the developed reservoir model seems to be more active at an optimum injected water temperature of 40 °C. Moreover, when engineered water was injected in a heterogeneous system, the generated H2S and souring onset were spiked by 2 times as opposed to that of the homogeneous system, attributed to better mixing of the engineered water injected and the formation water. This study accounts for SRB generation as well as heterogeneity and injected water temperature implications on H2S generated by engineered water injection within a unified biogeochemical model. This approach offers a straightforward yet comprehensive workflow for predicting and managing reservoir souring. By addressing fundamental mechanisms often overlooked, the proposed method brings a practical advancement to field operations and broadens the understanding of reservoir management and engineered water injection methods.
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Reports on the topic "Spectroscopic. kinetic and mechanistic study"

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Gupta, Malancha. Kinetic and Mechanistic Study of Vapor-Phase Free Radical Polymerization onto Liquid Surfaces. Office of Scientific and Technical Information (OSTI), December 2017. http://dx.doi.org/10.2172/1436439.

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Abe, Yasuhide, Yuma Ishizawa, Go Emori, Mitsuo Asanuma, Akira Iijima, Hideo Shoji, Kazuhito Misawa, et al. A Study of Supercharged HCCI Combustion using In-cylinder Spectroscopic Techniques and Chemical Kinetic Calculation. Warrendale, PA: SAE International, October 2013. http://dx.doi.org/10.4271/2013-32-9171.

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