Academic literature on the topic 'Chemical kinetic modeling'

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Journal articles on the topic "Chemical kinetic modeling":

1

Suleymanov, Yury. "Advancing chemical kinetic modeling." Science 372, no. 6537 (April 1, 2021): 44.2–44. http://dx.doi.org/10.1126/science.372.6537.44-b.

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Pitz, W. J., C. K. Westbrook, O. Herbinet, and E. J. Silke. "KS-2: Progress in Chemical Kinetic Modeling for Surrogate Fuels(Keynote Papers)." Proceedings of the International symposium on diagnostics and modeling of combustion in internal combustion engines 2008.7 (2008): 9–15. http://dx.doi.org/10.1299/jmsesdm.2008.7.9.

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Boukhalfa, Nora. "Chemical Kinetic Modeling of Methane Combustion." Procedia Engineering 148 (2016): 1130–36. http://dx.doi.org/10.1016/j.proeng.2016.06.561.

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ERTEKİN, Özlem. "Example of A Kinetic Mathematical Modeling in Food Engineering." ITM Web of Conferences 22 (2018): 01029. http://dx.doi.org/10.1051/itmconf/20182201029.

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Mathematical modeling of biochemical, chemical reaction processes facilitates understanding. The kinetics of these reaction processes can be analyzed mathematically and kinetics are presented as systems of differential equations. Mathematical model of a reaction kinetic is studied in this study. Bernoulli-Sub equation function method is used in this study. This example can be new model for food engineering applications.
5

Martínez, Haydee, Joaquín Sánchez, José-Manuel Cruz, Guadalupe Ayala, Marco Rivera, and Thomas Buhse. "Modeling of Scale-Dependent Bacterial Growth by Chemical Kinetics Approach." Scientific World Journal 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/820959.

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We applied the so-called chemical kinetics approach to complex bacterial growth patterns that were dependent on the liquid-surface-area-to-volume ratio (SA/V) of the bacterial cultures. The kinetic modeling was based on current experimental knowledge in terms of autocatalytic bacterial growth, its inhibition by the metabolite CO2, and the relief of inhibition through the physical escape of the inhibitor. The model quantitatively reproduces kinetic data of SA/V-dependent bacterial growth and can discriminate between differences in the growth dynamics of enteropathogenicE. coli,E. coli JM83, andSalmonella typhimuriumon one hand andVibrio choleraeon the other hand. Furthermore, the data fitting procedures allowed predictions about the velocities of the involved key processes and the potential behavior in an open-flow bacterial chemostat, revealing an oscillatory approach to the stationary states.
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Edeleva, Mariya, Paul H. M. Van Steenberge, Maarten K. Sabbe, and Dagmar R. D’hooge. "Connecting Gas-Phase Computational Chemistry to Condensed Phase Kinetic Modeling: The State-of-the-Art." Polymers 13, no. 18 (September 7, 2021): 3027. http://dx.doi.org/10.3390/polym13183027.

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In recent decades, quantum chemical calculations (QCC) have increased in accuracy, not only providing the ranking of chemical reactivities and energy barriers (e.g., for optimal selectivities) but also delivering more reliable equilibrium and (intrinsic/chemical) rate coefficients. This increased reliability of kinetic parameters is relevant to support the predictive character of kinetic modeling studies that are addressing actual concentration changes during chemical processes, taking into account competitive reactions and mixing heterogeneities. In the present contribution, guidelines are formulated on how to bridge the fields of computational chemistry and chemical kinetics. It is explained how condensed phase systems can be described based on conventional gas phase computational chemistry calculations. Case studies are included on polymerization kinetics, considering free and controlled radical polymerization, ionic polymerization, and polymer degradation. It is also illustrated how QCC can be directly linked to material properties.
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Escanciano, Itziar A., Mateusz Wojtusik, Jesús Esteban, Miguel Ladero, and Victoria E. Santos. "Modeling the Succinic Acid Bioprocess: A Review." Fermentation 8, no. 8 (July 31, 2022): 368. http://dx.doi.org/10.3390/fermentation8080368.

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Succinic acid has attracted much interest as a key platform chemical that can be obtained in high titers from biomass through sustainable fermentation processes, thus boosting the bioeconomy as a critical production strategy for the future. After several years of development of the production of succinic acid, many studies on lab or pilot scale production have been reported. The relevant experimental data reveal underlying physical and chemical dynamic phenomena. To take advantage of this vast, but disperse, kinetic information, a number of mathematical kinetic models of the unstructured non-segregated type have been proposed in the first place. These relatively simple models feature critical aspects of interest for the design, control, optimization and operation of this key bioprocess. This review includes a detailed description of the phenomena involved in the bioprocesses and how they reflect on the most important and recent models based on macroscopic and metabolic chemical kinetics, and in some cases even coupling mass transport.
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Westbrook, Charles K. "Chemical kinetic modeling of higher hydrocarbon fuels." AIAA Journal 24, no. 12 (December 1986): 2002–9. http://dx.doi.org/10.2514/3.9559.

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Silke, Emma J., William J. Pitz, Charles K. Westbrook, and Marc Ribaucour. "Detailed Chemical Kinetic Modeling of Cyclohexane Oxidation†." Journal of Physical Chemistry A 111, no. 19 (May 2007): 3761–75. http://dx.doi.org/10.1021/jp067592d.

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Lai, Jason Y. W., Kuang C. Lin, and Angela Violi. "Biodiesel combustion: Advances in chemical kinetic modeling." Progress in Energy and Combustion Science 37, no. 1 (February 2011): 1–14. http://dx.doi.org/10.1016/j.pecs.2010.03.001.

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Dissertations / Theses on the topic "Chemical kinetic modeling":

1

Jalan, Amrit. "Predictive kinetic modeling of low-temperature hydrocarbon oxidation." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91059.

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Abstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 221-235).
Low temperature oxidation in the gas and condensed phases has been the subject of experimental investigations for many decades owing to applications in many areas of practical significance like thermal stability, combustion, atmospheric chemistry and industrial syntheses. Owing to several practical limitations it has proven difficult to understand these processes at a mechanistic level from experiments alone. Developments in scientific computing have opened up computational chemistry and cheminformatics based tools as an attractive option for exploring and elucidating the kinetics of these complex processes through detailed kinetic modeling and requires efforts in three key areas: single reaction kinetics, reaction networks and coupling kinetics with mass/momentum/energy balance models. This thesis presents several contributions employing high-level electronic structure calculations, reaction rate theory, automated kinetic modeling and empirical correlations to further our mechanistic understanding of low-temperature oxidation in the gas and liquid phase. First, an extensible framework for automatic estimation of species thermochemistry in the solution phase is presented and validated. This framework uses the Linear Solvation Energy Relationship (LSER) formalism of Abraham/Mintz and co-workers for high-throughput estimation of [delta]G°solv(T) in over 30 solvents using solute descriptors estimated from group additivity. The performance of scaled particle theory (SPT) expressions for enthalpic-entropic decomposition of [delta]G°solv(T) is also discussed along with the associated computational issues. Second, the importance of solvent effects on free-radical kinetics is explored using tetralin oxidation as a case study. The solvent dependence for the main propagation and termination reactions are determined using the Polarizable Continuum (PCM) family of solvation models. Incorporating these kinetic solvent effects in detailed kinetic models suggest oxidation rates increase with solvent polarity, consistent with experiment. Following this, electronic structure methods and reaction rate theory are used elucidate mechanistic details of new pathways in liquid-phase and atmospheric oxidation. The first of these studies focuses on pathways that establish [gamma]-ketohydroperoxides (KHP), well-known products in low-temperature alkane oxidation, as precursors to acids through a two-step process. Ab initio calculations are used to identify pathways leading from KHP to a cyclic peroxide isomer which decomposes through novel concerted reactions into carbonyl and carboxylic acid products. High-level gas phase rate coefficients are obtained using DFT/WFT methods coupled with VTST/SCT calculations and multi-structural partition functions (QMs-T). Solvent effects are included using continuum dielectric solvation models and the predicted rate coefficients found to be in excellent agreement with experiment lending theoretical support to the 30-year old Korcek hypothesis. Next, insights from the Korcek reaction are extended to atmospheric chemistry where similar cyclic peroxides are formed by reactions of the Criegee Intermediate (*CH₂OO*) with double bonds. More specifically, the role of chemical activation in reactions between *CH₂OO* and C=O/C=C species is explored using master equation calculations to obtain phenomenological rate coefficients k(T,P). In the case of reactions with C=O, the yield of collisionally stabilized SOZ at atmospheric pressure was found to increase in the order HCHO < CH₃CHO < CH₃COCH₃ - At low pressures, chemically activated formation of organic acids was found to be the major product channel in agreement with recent direct measurements. Epoxide and CH₂=CHOH are predicted to be the major products for *CH₂OO* + C₂H₄ under atmospheric conditions. Finally, as a case study in coupling detailed chemical and physical models, the improved understanding of liquid phase oxidation developed above is used to build multi-physics models of diesel injector deposit formation that adversely affects fuel spray characteristics and engine efficiency. Octane is used as a model liquid fuel for detailed kinetic modeling of oxidative aging leading to deposit precursors. In addition to fuel chemistry, the immiscibility of polar oxidation products leading to 'soft deposit' is modeled using linear solvation energy relationships. The chemistry and phase separation models are coupled with physical processes like washing. The resulting framework is used to explore the sensitivity of deposit formation to various model parameters.
by Amrit Jalan.
Ph. D.
2

Moore, Jason Stuart. "Kinetic modeling and automated optimization in microreactor systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79195.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 127-138).
The optimization, kinetic investigation, or scale-up of a reaction often requires significant time and materials. Silicon microreactor systems have been shown advantageous for studying chemical reactions due to their small volume, rapid mixing, tight temperature control, large range of operating conditions, and increased safety. The primary goal of this thesis is to expand the capabilities of automated microreactor systems to increase their scope and efficiency. An automated optimization platform is built utilizing continuous inline IR analysis at the reactor exit, and a Paal-Knorr reaction is chosen as the first example chemistry. This reaction, where both the first and second reaction steps affect the overall rate, leads to a more complex conversion profile. A steepest descent algorithm is first used to optimize conversion and production rates. The steepest descent algorithm tends to move slowly up the production rate ridge, significantly reducing efficiency. This issue is overcome by using a Fletcher-Reeves conjugate gradient method, which finds the constrained optimum in much fewer experiments. The conjugate gradient algorithm is then further improved upon by incorporating a hybrid Armijo line search and bisection contraction method. However, the conversion is only about 40% at the maximum in production rate. A further optimization is performed using a quadratic loss function to penalize conversions of less than 85%. This optimization of production rate led to an optimum at higher residence time, where a conversion of 81% is achieved. In the conventional view of reaction analysis, batch reactions are thought to be significantly more efficient in generating time-course reaction data than flow reactions, which are generally limited to steady-state studies. By taking advantage of the low dispersion in microreactors, successive fluid elements of the reactor may be treated as separate batch reactors. By continuously manipulating the reaction flow rate and tracking the total reaction time of each fluid element, time-course data analogous to that conventionally derived from batch reactors are generated and shown to be in agreement with steady-state results. Palladium-catalyzed carbonylation and CN-coupling reactions are used extensively in laboratory synthesis and industrial processes. The primary reaction studied involves the coupling of bromobenzene and morpholene with the addition of one or two carbonyl groups. The dependence of reaction conversion and selectivity on temperature, CO pressure, and Pd concentration are investigated using GC and IR analysis. A temperature ramp method is employed to rapidly investigate temperature effects on reaction rate and selectivity. The experiments reveal a change in the rate determining step at approximately 120 °C and corresponded well with GC data taken at several setpoints. In addition, the activation energy of the lower temperature regime as determined by this IR analysis is found to be very similar to that found by GC analysis, the experiments for which took significantly longer both to perform and analyze. Furthermore, the data collected from these experiments are used to fit a kinetic model. Multicomponent reactions (MCRs) are important to drug discovery by affording complex products in only a single step. By linking two of these MCRs, a Petasis boronic acid-Mannich reaction and an Ugi reaction, six different components could be incorporated in a relatively short time. The kinetics of each reaction are investigated with online UPLC analysis, allowing for quantification of a number of reaction components, including monitoring the formation of side products that were unknown prior to experimentation. A simple microcalorimeter is built using thermoelectric elements and a silicon microreactor to experimentally determine the heats of reaction during flow to allow for understanding the heat transfer needs for scale up. The result from the nitration of benzene, which has a heat of reaction of -117 kJ/mol, is -118.6 +/- 2.4 kJ/mol. The experimentally determined values are close to the known values; however, there is significant noise in the output during the reaction due to the two-phase nature of the reaction. The Paal-Knorr reaction is further investigated to determine the limits of sensitivity of the microcalorimetry system. A continuous concentration ramp experiment is performed with online IR analysis, enabling the thermoelectric output to be adjusted for reaction rate to determine the sensitivity to the heat of reaction. Below approximately 2 M, the sensitivity decreases rapidly, largely due to noise in the temperature control and concentration. To attempt to correct for the former, a calorimetry system with larger thermal mass is constructed and shown to decrease the sensitivity limit to 1 M, corresponding to a heat flow of approximately 0.05 W.
by Jason Stuart Moore.
Ph.D.
3

Akih, Kumgeh Benjamin. "Shock tube studies and chemical kinetic modeling of oxygenated hydrocarbon ignition." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103701.

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As a contribution towards understanding, modeling and controlling the combustion of oxygenated hydrocarbons such as biofuels, the high-temperature ignition of a series of relevant molecules has been investigated behind reflected shock waves at pressures ranging from 1 atm to 13 atm. Short chain biodiesel surrogates, methyl and ethyl esters, have been investigated. Methyl esters of formic to butanoic acids have been investigated in order to uncover the trends in their ignition delay times. The trends have further been explored by means of computational quantum chemical calculations. While most of these surrogates portray similar ignition behavior, the influence of structure with respect to terminal methyl groups and the presence or absence of secondary C–H bonds have been observed as in the case of methyl acetate with longer ignition delay times. The role of the alkyl group on the ester reactivity has been investigated by comparing methyl and ethyl esters, with the result that ethyl esters are generally more reactive. Apart from these biodiesel surrogates, selected C3 oxygenates, relevant to combustion have been investigated. A chemical kinetic mechanism for the high-temperature oxidation of propanal is developed and tested. Propanal, like other aldehydes, belongs to the group of intermediate species which occur in the combustion of almost all hydrocarbons, but their accurate prediction in combustion modeling is challenging. Targeted studies of the submodels of these compounds are expected to contribute towards predictive chemical kinetic modeling. The developed mechanism also shows encouraging performance in the prediction of acetaldehyde (ethanal) ignition. Ethanol is another biofuel widely used in spark-ignition engines. There is also interest in using this fuel in diesel and Homogeneous Charge Compression Ignition (HCCI) engine concepts. This is in line with the need for tailor-made, flexible fuels for wide range applications in energy conversion. Ethanol ignition modification by isopropyl nitrate (IPN), isopropyl formate (IPF) and water has been investigated. It is found that whereas IPN improves the ignition performance of ethanol (shorter ignition delay times), IPF increases its ignition resistance (longer ignition delay times), so that it can be used as an anti-knock agent. It is further observed that at temperatures above 1400 K, IPN addition ceases to improve the ignition of ethanol. Wet ethanol ignition reveals that at the same post-shock temperature water has an ignition promoting effect. The feasibility of igniting wet ethanol raises the prospect of reducing ethanol production cost (distillation) by using ethanol with allowable water content, albeit with a lower specific energy content. The ignition behavior of the biodiesel surrogate, methyl butanoate, and the diesel surrogate, n-heptane, is compared. Similar behavior is observed under stoichiometric conditions, with slight differences under rich conditions. A skeletal mechanism is proposed for the combustion of blends of the two surrogates. The skeletal mechanism is derived from reduced skeletal mechanisms of literature mechanisms for n-heptane and methyl butanoate obtained on the basis of extensive ignition sensitivity analyses and chemical kinetic insight. These reduced skeletal models have been found to perform reasonably well when compared to predictions by their original detailed mechanisms with respect to ignition, flame propagation and the structure of an opposed flow flame in the mixture fraction space. A systematic approach has been taken in this work to compare the reactivity of fuels, which leads to insight on trends, similarities and differences in global ignition behavior. The combination of experiments, analyses, computations and modeling demonstrates the synergy required to address problems in modern combustion science and technology.
En tant que contribution à la compréhension, la modélisation et le contrôle de la combustion des hydrocarbures oxygénés tels que les biocarburants, l'auto-allumage à haute température d'une série de molécules a été étudiée avec la méthode de tube a onde de choc pour les pressions entre 1 atm et 13 atm. Les molécules représentatives du biodiésel, c'est à dire des esters méthyliques et éthyliques, ont été étudiées. Les esters méthyliques d'acide formique jusqu'à butanoique ont été étudiés afin de découvrir l'influence de leurs structures sur l'auto-allumage. Cette relation a aussi été examinée avec les calculs de la chimique quantique. Alors que la pluparts de ces esters sont marqués par des délais d'auto-allumage similaires, les influences des groupes méthyliques terminales, et la présence ou absence des liaisons secondaires de C-H, ont été identifiées, comme dans le cas d'acétate de méthyle, caractérisé par les plus longs délais. Le rôle du groupe alkyle sur la réactivité d'ester a été étudié en comparant des esters méthyliques avec les esters éthyliques. Les esters éthyliques sont généralement plus réactifs que les esters méthyliques du même acide. De la même manière, sont investigués quelques hydrocarbures oxygénés, dont leur cinétique d'oxydation est impliquée dans la combustion des biocarburants et carburants pétrolifères. Un mécanisme de la cinétique chimique pour la combustion du propanal à haute température a été développé et validé. Le propanal, comme d'autres aldéhydes, appartient au groupe des espèces intermédiaires qui se forment pendant la combustion de presque tous les hydrocarbures, mais leur modélisation reste imprécise. Des études consacrées à la compréhension des sous-modèles de ces molécules devraient contribuer à la modélisation avancée de la cinétique chimique de la combustion. Le mécanisme proposé prédit aussi les délais d'auto-allumage d'acétaldéhyde, dont le sous-mécanisme est inclus. L'éthanol est un biocarburant largement utilisé dans les moteurs à allumage commandé. Il y a également intérêt à utiliser ce carburant dans les moteurs à allumage par compression. Ceci est en accord avec la nécessité de développer des carburants flexibles pour des moteurs divers. La modification de l'auto-allumage de l'éthanol par des additifs chimiques comme le nitrate d'isopropyle (IPN), le formiate d'isopropyle (IPF) et l'eau a été investiguée. Il se trouve que, alors que l'IPN améliore la tendance à l'auto-allumage de l'éthanol (délais plus courts), l'IPF augmente sa résistance à l'autoallumage, de sorte que ce dernier peut être utilisé comme additif pour supprimer l'autoallumage. Pour une même température, l'auto-allumage de l'éthanol contenant de l'eau se révèle accélérée. Un mécanisme pour la combustion des mélanges de diesel et du biodiesel est également proposé. Le mécanisme est dérivé de la réduction des mécanismes détaillés pour le n-heptane et le butanoate de méthyle obtenus sur la base de l'analyse de sensitivité de l'auto-allumage. Cette méthode comparative systématique et innovatrice cherche à caractériser les propriétés des carburants oxygénés en vue de révéler les similitudes et les différences. Les résultats servent à l'optimisation des modèles cinétiques chimiques ainsi qu'à la compréhension de la cinétique de combustion d'une série d'espèces oxygénées. Des corrélations de délais d'auto-allumage sont également proposées pour l'application pratique. Le mécanisme proposé pour les mélanges diesel et biodiesel se prête à l'étude de la combustion dans les écoulements turbulents.
4

Alecu, Ionut M. Marshall Paul. "Kinetic studies and computational modeling of atomic chlorine reactions in the gas phase." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/ark:/67531/metadc12071.

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Alecu, Ionut M. "Kinetic studies and computational modeling of atomic chlorine reactions in the gas phase." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12071/.

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The gas phase reactions of atomic chlorine with hydrogen sulfide, ammonia, benzene, and ethylene are investigated using the laser flash photolysis / resonance fluorescence experimental technique. In addition, the kinetics of the reverse processes for the latter two elementary reactions are also studied experimentally. The absolute rate constants for these processes are measured over a wide range of conditions, and the results offer new accurate information about the reactivity and thermochemistry of these systems. The temperature dependences of these reactions are interpreted via the Arrhenius equation, which yields significantly negative activation energies for the reaction of the chlorine atom and hydrogen sulfide as well as for that between the phenyl radical and hydrogen chloride. Positive activation energies which are smaller than the overall endothermicity are measured for the reactions between atomic chlorine with ammonia and ethylene, which suggests that the reverse processes for these reactions also possess negative activation energies. The enthalpies of formation of the phenyl and β-chlorovinyl are assessed via the third-law method. The stability and reactivity of each reaction system is further rationalized based on potential energy surfaces, computed with high-level ab initio quantum mechanical methods and refined through the inclusion of effects which arise from the special theory of relativity. Large amounts of spin-contamination are found to result in inaccurate computed thermochemistry for the phenyl and ethyl radicals. A reformulation of the computational approach to incorporate spin-restricted reference wavefunctions yields computed thermochemistry in good accord with experiment. The computed potential energy surfaces rationalize the observed negative temperature dependences in terms of a chemical activation mechanism, and the possibility that an energized adduct may contribute to product formation is investigated via RRKM theory.
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Castaneda-Lopez, Luis Carlos. "Kinetic modeling of the hydrotreatment of light cycle oil/diesel." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1061.

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Wu, Kuo-chʻun 1968. "Chemical kinetic modeling of oxidation of hydrocarbon emissions in spark ignition engines." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/35377.

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Boddapati, Aparna. "Modeling cure depth during photopolymerization of multifunctional acrylates." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33934.

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The photopolymerization of multifunctional acrylates leads to the formation of a complex and insoluble network due to cross-linking. This characteristic is a useful property for stereolithography applications, where solid parts of the desired shape are cured using a pre-determined energy exposure profile. Traditionally, the required energy exposure is determined using a critical energy--depth of penetration, or Ec--Dp, model. The parameters Ec and Dp, are usually fit to experimental data at a specific resin composition and cure intensity. As a result, since the Ec--Dp model does not explicitly incorporate cure kinetics, it cannot be used for a different set of process conditions without first obtaining experimental data at the new conditions. Thus, the Ec--Dp model does not provide any insight when a new process needs to be developed, and the best processing conditions are unknown. The kinetic model for multifunctional acrylate photopolymerization presented here is based on a set of ordinary differential equations (ODE), which can be used to predict part height versus exposure condition across varying resin compositions. Kinetic parameter information used in the model is obtained by fitting the model to double bond conversion data from Fourier Transform Infrared Spectroscopy (FTIR) measurements. An additional parameter, the critical conversion value, is necessary for determining the formation of a solid part of the desired height. The initial rate of initiation, Ri, combines all the factors that impact part height, and therefore, it is an important quantity that is required in order to find the critical conversion value. The critical conversion value is estimated using the Ri and Tgel value from microrheology measurements. Information about network connectivity, which can be used to get properties such as molecular weight, cannot be derived from models using traditional mass-action kinetics for the cross-linking system. Therefore, in addition to modeling the reaction using the ODE based model, the results from a statistical model based on Kinetic Monte Carlo (KMC) principles are also shown here. The KMC model is applicable in situations where the impact of chain length on the kinetics or molecular weight evolution is of interest. For the present project, the detailed information from network connectivity was not required to make part height predictions, and the conversion information from the ODE model was sufficient. The final results show that the kinetic ODE model presented here, based on the critical conversion value, captures the impact of process parameters such as initiator concentration, light intensity, and exposure time, on the final part height of the object. In addition, for the case of blanket cure samples, the part height predictions from the ODE model make comparable predictions to the Ec--Dp model. Thus, the ODE model presented here is a versatile tool that can be used to determine optimum operating conditions during process development.
9

Lee, Chuang-Chung. "Kinetic modeling of amyloid fibrillation and synaptic plasticity as memory loss and formation mechanisms." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/49893.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2008.
Includes bibliographical references (p. 141-150).
The principles of biochemical kinetics and system engineering are applied to explain memory-related neuroscientific phenomena. Amyloid fibrillation and synaptic plasticity have been our focus of research due to their significance. The former is related to the pathology of many neurodegenerative diseases and the later is regarded as the principal mechanism underlying learning and memory. Claimed to be the number one cause of senile dementia, Alzheimer's disease (AD) is one of the disorders that involve misfolding of amyloid protein and formation of insoluble fibrils. Although a variety of time dependent fibrillation data in vitro are available, few mechanistic models have been developed. To bridge this gap we used chemical engineering concepts from polymer dynamics, particle mechanics and population balance models to develop a mathematical formulation of amyloid growth dynamics. A three-stage mechanism consisting of natural protein misfolding, nucleation, and fibril elongation phases was proposed to capture the features of homogeneous fibrillation responses. While our cooperative laboratory provided us with experimental findings, we guided them with experimental design based on modeling work. It was through the iterative process that the size of fibril nuclei and concentration profiles of soluble proteins were elucidated. The study also reveals further experiments for diagnosing the evolution of amyloid coagulation and probing desired properties of potential fibrillation inhibitors. Synaptic plasticity at various time ranges has been studied experimentally to elucidate memory formation mechanism. By comparison, the theoretical work is underdeveloped and insufficient to explain some experiments. To resolve the issue, we developed models for short-term, long-term, and spike timing dependent synaptic plasticity, respectively.
(cont.) First, presynaptic vesicle trafficking that leads to the release of glutamate as neurotransmitter was taken into account to explain short-term plasticity data. Second, long-term plasticity data lasting for hours after tetanus stimuli has been matched by a calcium entrapment model we developed. Model differentiation was done to demonstrate the better performance of calcium entrapment model than an alternative bistable theory in fitting graded long-term potentiation responses. Finally, to decipher spike timing dependent plasticity (STDP), we developed a systematic model incorporating back propagation of action potential, dual requirement of NMDA receptors, and calcium dependent plasticity. This built model is supported by five different types of STDP experimental data. The accumulation of amyloid beta has been found to disrupt the sustainable modification of long-term synaptic plasticity which might explain the inability of AD patients to form new memory at early stage of the disease. Yet the linkage between the existence of amyloid beta species and failure of long-term plasticity was unclear. We suggest that the abnormality of calcium entrapment function caused by amyloid oligomers is the intermediate step that eventually leads to memory loss. Unsustainable calcium level and decreased postsynaptic activities result into the removal or internalization of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. The number of AMPA receptors as the indicators of synaptic strength may result into disconnection between neurons and even neuronal apoptosis. New experiments have been suggested to validate this hypothesis and to elucidate the pathology of Alzheimer's disease.
by Chuang-Chung (Justin) Lee.
Ph.D.
10

Bandstra, Joel Zachary. "Kinetic modeling of heterogeneous chemical reactions with applications to the reduction of environmental contaminants on iron metal." Full text open access at:, 2005. http://content.ohsu.edu/u?/etd,280.

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Books on the topic "Chemical kinetic modeling":

1

H, Galina, ed. Grafting, characterization techniques, kinetic modeling. Berlin: Springer, 1998.

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M. A. J. S. van Boekel. Kinetic modeling of reactions in foods. Boca Raton: Taylor & Francis, 2008.

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G, Compton R., and Hancock G, eds. Applications of kinetic modelling. Amsterdam: Elsevier, 1999.

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Prof, Carr Robert W., ed. Modeling of chemical reactions. Amsterdam: Elsevier, 2007.

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Coker, A. Kayode. Modeling of chemical kinetics and reactor design. Boston, MA: Gulf Professional Pub., 2001.

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United States. Federal Highway Administration. Exploring cement hydration kinetics: International summit on cement hydration kinetics and modeling. Washington, D.C.]: U.S. Dept. of Transportation, Federal Highway Administration, 2010.

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Boekel, Tiny Van. Kinetic modelling of reactions in foods. Boca Raton: Taylor & Francis, 2008.

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B, DeMore W., NASA Panel for Data Evaluation., and Jet Propulsion Laboratory (U.S.), eds. Chemical kinetics and photochemical data for use in stratospheric modeling. Pasadena, Calif: National Aeronautics and Space Administration, Jet Propulsion Laboratory, California Institute of Technology, 1992.

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Kopin, Liu, and Wagner Albert 1945-, eds. The chemical dynamics and kinetics of small radicals. Singapore: World Scientific, 1995.

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B, DeMore W., and Jet Propulsion Laboratory (U.S.), eds. Chemical kinetics and photochemical data for use in stratospheric modeling: Evaluation number 11. Pasadena, Calif: National Aeronautics and Space Administration, Jet Propulsion Laboratory, California Institute of Technology, 1994.

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Book chapters on the topic "Chemical kinetic modeling":

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Jakobsen, Hugo A. "Elementary Kinetic Theory of Gases." In Chemical Reactor Modeling, 183–365. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-05092-8_2.

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Grünfeld, Cecil P. "Nonlinear Kinetic Models with Chemical Reactions." In Modeling in Applied Sciences, 173–224. Boston, MA: Birkhäuser Boston, 2000. http://dx.doi.org/10.1007/978-1-4612-0513-5_6.

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Campbell, Jerry L., Kannan Krishnan, Harvey J. Clewell, and Melvin E. Andersen. "Modeling Kinetic Interactions of Chemical Mixtures." In Principles and Practice of Mixtures Toxicology, 125–57. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2010. http://dx.doi.org/10.1002/9783527630196.ch5.

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Froment, G. F. "Fundamental Kinetic Modeling of Complex Processes." In Chemical Reactions in Complex Mixtures, 77–100. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4684-6530-3_5.

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Sapre, A. V. "Kinetic Modeling at Mobil: An Historical Perspective." In Chemical Reactions in Complex Mixtures, 222–53. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4684-6530-3_12.

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Tolsma, John E., Brian Simpson, Taeshin Park, and Jason Mustakis. "Modeling, Optimization, and Applications of Kinetic Mechanisms with OpenChem." In Chemical Engineering in the Pharmaceutical Industry, 137–53. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470882221.ch10.

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Varfolomeev, Sergey, Viktor Bykov, and Svetlana Tsybenova. "Kinetic modelling of processes in the cholinergic synapse. Mechanisms of functioning and control methods." In ORGANOPHOSPHORUS NEUROTOXINS, 127–39. ru: Publishing Center RIOR, 2020. http://dx.doi.org/10.29039/22_127-139.

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The kinetic model describing the dynamics of synaptic “discharge” taking into account the kinetics of the injection of the neurotransmitter into the synaptic cleft, the pH-dependence of catalytic activity of the enzyme and diffusion withdrawal of protons is proposed and studied. In the framework of the kinetic model, the functioning of the cholinergic synapse is considered. The results of mathematical modeling of changes in the level of acetylcholine, induced pH impulse, the influence of the frequency of impulse transfer and inhibition of acetylcholinesterase are presented. Physico-chemical explanation for a number of important physiological phenomena, such as neuromuscular paralysis, the molecular mechanism of neurological memory, actions of nerve poisons and toxins and Alzheimer’s disease is given.
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Varfolomeev, Sergey, Viktor Bykov, and Svetlana Tsybenova. "Kinetic modelling of processes in the cholinergic synapse. Mechanisms of functioning and control methods." In Organophosphorous Neurotoxins, 121–33. ru: Publishing Center RIOR, 2020. http://dx.doi.org/10.29039/chapter_5e4132b600e1c6.27895580.

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The kinetic model describing the dynamics of synaptic “discharge” taking into account the kinetics of the injection of the neurotransmitter into the synaptic cleft, the pH-dependence of catalytic activity of the enzyme and diffusion withdrawal of protons is proposed and studied. In the framework of the kinetic model, the functioning of the cholinergic synapse is considered. The results of mathematical modeling of changes in the level of acetylcholine, induced pH impulse, the influence of the frequency of impulse transfer and inhibition of acetylcholinesterase are presented. Physico-chemical explanation for a number of important physiological phenomena, such as neuromuscular paralysis, the molecular mechanism of neurological memory, actions of nerve poisons and toxins and Alzheimer’s disease is given.
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Froment, G. F. "Kinetic Modeling of Complex Processes. Thermal Cracking and Catalytic Hydrocracking." In Chemical Reactor Technology for Environmentally Safe Reactors and Products, 409–24. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2747-9_16.

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Knoth, Oswald, and Ralf Wolke. "A Comparison of Fast Chemical Kinetic Solvers in a Simple Vertical Diffusion Model." In Air Pollution Modeling and Its Application X, 287–94. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-1817-4_32.

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Conference papers on the topic "Chemical kinetic modeling":

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WESTBROOK, C. "Chemical kinetic modeling of higher hydrocarbon fuels." In 24th Aerospace Sciences Meeting. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1986. http://dx.doi.org/10.2514/6.1986-139.

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Tamura, Todd, and Simone Hochgreb. "Chemical Kinetic Modeling of the Oxidation of Unburned Hydrocarbons." In International Fuels & Lubricants Meeting & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1992. http://dx.doi.org/10.4271/922235.

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Westbrook, Charles K., and William J. Pitz. "Chemical Kinetic Modeling of Combustion of Practical Hydrocarbon Fuels." In 40th Annual Earthmoving Industry Conference. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1989. http://dx.doi.org/10.4271/890990.

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Slavinskaya, N. A. "Chemical Kinetic Modeling in Coal Gasification Processes: An Overview." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23362.

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Coal is the fuel most able to cover world deficiencies in oil and natural gas. This motivates the development of new and more effective technologies for coal conversion into other fuels. Such technologies are focused on coal gasification with production of syngas or gaseous hydrocarbon fuels, as well as on direct coal liquefaction with production of liquid fuels. The benefits of plasma application in these technologies is based on the high selectivity of the plasma chemical processes, the high efficiency of conversion of different types of coal including those of low quality, relative simplicity of the process control, and significant reduction in the production of ashes, sulphur, and nitrogen oxides. In the coal gasifier, two-phase turbulent flow is coupled with heating and evaporation of coal particles, devolatilization of volatile material, the char combustion (heterogeneous/porous oxidation) or gasification, the gas phase reaction/oxidation (homogeneous oxidation) of gaseous products from coal particles. The present work reviews literature data concerning modelling of coal gasification. Current state of related kinetic models for coal particle gasification, plasma chemistry and CFD tools is reviewed.
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Ateka, Ainara, Ander Portillo, Miguel Sanchez-Contador, Javier Bilbao, and Andrés T. Aguayo. "Core-shell catalysts for the direct synthesis of DME. Kinetic modeling." In 14th Mediterranean Congress of Chemical Engineering (MeCCE14). Grupo Pacífico, 2020. http://dx.doi.org/10.48158/mecce-14.dg.05.01.

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Havstad, Mark, Salvador M. Aceves, Matthew McNenly, William Piggott, K. Dean Edwards, Robert Wagner, C. Stuart Daw, and Charles E. A. Finney. "Detailed Chemical Kinetic Modeling of Iso-octane SI-HCCI Transition." In SAE 2010 World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2010. http://dx.doi.org/10.4271/2010-01-1087.

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Curran, H. J., E. M. Fisher, P. A. Glaude, N. M. Marinov, W. J. Pitz, C. K. Westbrook, D. W. Layton, et al. "Detailed Chemical Kinetic Modeling of Diesel Combustion with Oxygenated Fuels." In SAE 2001 World Congress. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2001. http://dx.doi.org/10.4271/2001-01-0653.

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Mawid, M. A., T. W. Park, B. Sekar, and C. Arana. "Detailed Chemical Kinetic Modeling of JP-8/Jet-A Ignition and Combustion." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68829.

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Significant progress towards development and validation of a detailed chemical kinetic mechanism for the US Air Force JP-8 fuel is presented in this article. Three detailed chemical kinetic mechanisms for three JP-8 surrogate fuels, as given in Table I, were developed and reported in this study. The main objective is to investigate the performance of the developed three mechanisms for three different surrogate fuel blends and determine the suitability of each mechanism to chemically model the US Air Force petroleum-derived JP-fuel. The detailed JP-8 chemical kinetic reaction mechanism, we have been developing [1–3] for a 12-component surrogate fuel blend, has been used as a basis for the development of two additional detailed reaction mechanisms for the other two surrogate fuel mixtures. Submechanisms for the monosubstituted aromatics such as toluene, m-xylene, butylbenzene, and for the bicyclic aromatics such as 1-methylnaphthalene were all assembled and integrated with the detailed JP-8 reaction mechanism [1–3]. Pressure-dependent rate parameters up to 10 atmospheres for 41 reactions were also included. The three mechanisms were evaluated by predicting the ignition and combustion characteristics of a JP-8 fuel-air mixture in Plug Flow Reactor (PFR) and a Perfectly-Stirred Reactor (PSR) over a temperature range of 933–1020 K and pressure of 1 atm. The results indicated that overall the mechanism for the 6-component JP-8 surrogate 3 (Table I) can predict similar ignition-delay periods as those predicted by the 12-component JP-8 surrogate fuel 1 for atmospheric pressure condition. However, the PSR calculations pointed out to the existence of differences in lighter hydrocarbon species concentration profiles such as CH4, C2H4, C3H6, and C4H8 and important emission species such as CO and CO2 as predicted by the mechanisms that exhibited comparable ignition delay times. The study suggests that, for the conditions considered here, that the developed mechanisms still require further evaluation under various combustion environments, including transport phenomena, to determine the suitability of the chemical kinetic mechanism for either surrogate fuel 1 or 3 to chemically simulate the actual US Air Force JP-8 fuel.
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Paschkewitz, J., J. Shang, J. Miller, and T. Madden. "An assessment of COIL physical property and chemical kinetic modeling methodologies." In 31st Plasmadynamics and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2000. http://dx.doi.org/10.2514/6.2000-2574.

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Kitamura, Takaaki, Takayuki Ito, Jiro Senda, and Hajime Fujimoto. "Detailed Chemical Kinetic Modeling of Diesel Spray Combustion with Oxygenated Fuels." In SAE 2001 World Congress. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2001. http://dx.doi.org/10.4271/2001-01-1262.

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Reports on the topic "Chemical kinetic modeling":

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PItz, W., C. Westbrook, and O. Herbinet. Chemical Kinetic Modeling of Advanced Transportation Fuels. Office of Scientific and Technical Information (OSTI), January 2009. http://dx.doi.org/10.2172/947237.

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Pitz, W., and C. Westbrook. Chemical Kinetic Modeling of Hydrogen Combustion Limits. Office of Scientific and Technical Information (OSTI), April 2008. http://dx.doi.org/10.2172/928549.

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Olsen, Mitchell, and Willson. L52248 Investigation of Formaldehyde Chemical Kinetics. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2004. http://dx.doi.org/10.55274/r0011246.

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The program is divided into two parts, which are (1) chemical kinetic modeling and (2) plug flow reactor tests. The chemical kinetic modeling focuses on the development of a model that can accurately predict formaldehyde formation and destruction. The most recent version of Chemkin is utilized with various kinetic mechanisms, including GRI-Mech. Numerous kinetic mechanisms are examined in order to select the most accurate one for predicting formaldehyde formation and destruction. The plug flow reactor tests consist of a series of steady state experimental investigations aimed at characterizing formaldehyde. Formaldehyde concentrations in the reactor are measured with an FTIR.
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Pitz, W., C. Westbrook, and E. Silke. Chemical Kinetic Modeling of Combustion of Automotive Fuels. Office of Scientific and Technical Information (OSTI), November 2006. http://dx.doi.org/10.2172/897957.

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Koert, D. N., W. J. Pitz, J. W. Bozzelli, and N. P. Cernansky. Chemical kinetic modeling of high pressure propane oxidation and comparison to experimental results. Office of Scientific and Technical Information (OSTI), November 1995. http://dx.doi.org/10.2172/179187.

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Koert, D. N., W. J. Pitz, J. W. Bozzelli, and N. P. Cernansky. Chemical kinetic modeling of high pressure propane oxidation and comparison to experimental results. Revision 1. Office of Scientific and Technical Information (OSTI), February 1996. http://dx.doi.org/10.2172/244540.

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Linker, Taylor, and Timothy Jacobs. PR-457-18204-R01 Variable Fuel Effects on Legacy Compressor Engines Phase IV - Predictive NOx Modeling. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), May 2019. http://dx.doi.org/10.55274/r0011584.

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The ultimate goal of this work is to improve the current control methods for large bore, lean burn natural gas engines in order to combat performance and emissions issues during variable fuel composition events. This will be achieved in the long term by simulating the effects of variable fuel composition on a large bore, natural gas engine and developing engine control strategies which work to mitigate adverse effects. The work of Phase IV adds onto previous work by enabling the prediction of NOxemissions in the validated, full-scale engine simulation of a Cooper-Bessemer GMWH-10C developed in Phase III. A sweep of fuel composition was also performed to assess the effect that variable fuel composition has on in-cylinder properties and NOxemissions. Engine-out NOxwas predicted via a chemical kinetic mechanism which was implemented into the existing engine simulation. The mechanism dictates the composition of combustion products in each cylinder, including NO and NO2(NOx). NOxlevels were measured at the simulation exhaust to compare with the experimental NOxdata acquired as part of the data collection carried out in Phase III of this project. The prediction was tuned in order to achieve the closest prediction to real measured NOxvalues. A preliminary sweep of fuel composition was completed by varying the mole fractions of ethane and propane within the natural gas compositions used in the simulation. Changes in in-cylinder pressure, location of peak pressure, in-cylinder temperature, and engine-out NOxwere evaluated based on their trend-wise behavior and compared qualitatively to expected results.
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Maranas, Costas D. Ensemble cell-wide kinetic modeling of anaerobic organisms to support fuels and chemicals production. Office of Scientific and Technical Information (OSTI), November 2018. http://dx.doi.org/10.2172/1481196.

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Waganet, R. J., John Duxbury, Uri Mingelgrin, John Hutson, and Zev Gerstl. Consequences of Nonequilibrium Pesticide Fate Processes on Probability of Leaching from Agricultural Lands. United States Department of Agriculture, January 1994. http://dx.doi.org/10.32747/1994.7568769.bard.

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Pesticide leaching in heterogeneous field soils is relatively unstudied and is the focus of this project. A wide variety of heterogeneous soils exist, characterized by processes that result from the presence of structural cracks, worm holes, and other preferred pathways within which the majority of transport can occur (called physical non-equilibrium processes), along with the presence of sorption processes that are both equilibrium and kinetic (chemical non-equilibrium processes). Previous studies of pesticide leaching have focused primarily on relatively homogeneous soils, which are less widely distributed in nature, but more studied due to the relative ease with which quantitative theory can be applied to interpret experimental results. The objectives of the proposed project were: first, to gain greater insight into the basic physical and chemical processes that characterize non-equilibrium systems, second, to improve our ability to predict pesticide leaching in heterogeneous field soils, and third, to estimate the consequences of non-equilibrium processes at the field scale by conducting an analysis of the probability of pesticide leaching when non-equilibrium processes prevail. The laboratory, theoretical and modelling aspects of the project were successful; the field aspects less so. We gained greater insight into basic processes in heterogeneous field soils, and we improved and tested tools (simulation models) and the methodology of using such tools for assessing the probability of pesticide leaching as a contribution to broader risk analysis efforts.
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Committee on Toxicology. COT FSA PBPK for Regulators Workshop Report 2021. Food Standards Agency, April 2024. http://dx.doi.org/10.46756/sci.fsa.tyy821.

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The future of food safety assessment in the UK depends on the Food Standards Agency’s (FSA) adaptability and flexibility in responding to and adopting the accelerating developments in science and technology. The Tox21 approach is an example of one recent advancement in the development of alternative toxicity testing approaches and computer modelling strategies for the evaluation of hazard and exposure (New Approach Methodologies (NAMs). A key aspect is the ability to link active concentrations in vitro to likely concentrations in vivo, for which physiologically based pharmacokinetic (PBPK) modelling is ideally suited. The UK FSA and the Committee on Toxicity of Chemicals in Food, Consumer Products, and the Environment (COT) held an “PBPK for Regulators” workshop with multidisciplinary participation, involving delegates from regulatory agencies, government bodies, academics, and industry. The workshop provided a platform to enable expert discussions on the application of PBPK to health risk assessment in a regulatory context. Presentations covered current application of PBPK modelling in the agrochemical industry for in vitro to in vivo extrapolation (IVIVE), pharmaceutical industry for drug absorption related issues (e.g., the effect of food on drug absorption) and drug-drug interaction studies, as well as dose extrapolations to special populations (e.g., those with a specific disease state, paediatric/geriatric age groups, and different ethnicities), environmental chemical risk assessment, an overview of the current regulatory guidance and a PBPK model run-through. This enabled attendees to consider the wide potential and fitness for purpose of the application of PBPK modelling in these fields. Attendees considered applicability in the context of future food safety assessment for refining exposure assessments of chemicals with narrow margins of exposure and/or to fill data gaps from more traditional approaches (i.e., data from animal testing). The overall conclusions from the workshop were as follows: PBPK modelling tools were applicable in the areas of use covered, and that expertise was available (though it is in small numbers). PBPK modelling offers opportunities to address questions for compounds that are otherwise not possible (e.g., considerations of human variability in kinetics) and allows identification of “at risk” subpopulations. The use of PBPK modelling tends to be applied on a case-by-case basis and there appears to be a barrier to widespread acceptance amongst regulatory bodies due to the lack of available in-house expertise (apart from some medical and environmental agencies such as the European Medicines Agency, United States Food and Drug Administration, and the US Environmental Protection Agency, respectively). Familiarisation and further training opportunities on the application of PBPK modelling using real world case studies would help in generating interest and developing more experts in the field, as well as furthering acceptance. In a regulatory context, establishing fitness for purpose for the use of PBPK models requires transparent discussion between regulatory agencies, government bodies, academics, and industry and the development of a harmonised guidance such as by the Organisation for Economic Co-operation and Development (OECD) would provide a starting point. Finally, PBPK modelling is part of the wider “new approach methodologies” for risk assessment, and there should be particular emphasis in modelling both toxicodynamics and toxicokinetics.

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