Literatura académica sobre el tema "Detailed kinetics model"
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Artículos de revistas sobre el tema "Detailed kinetics model"
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Mai, Tam V. T., Minh v. Duong, Hieu T. Nguyen y Lam K. Huynh. "Detailed kinetics of tetrafluoroethene ozonolysis". Physical Chemistry Chemical Physics 20, n.º 44 (2018): 28059–67. http://dx.doi.org/10.1039/c8cp05386c.
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The reaction mechanism was explored at the CCSD(T)/CBS//B3LYP/aug-cc-pVTZ level. Detailed kinetic analysis was firstly carried out using an ME/RRKM rate model with the inclusion of anharmonic and tunneling treatments. 1,3-Cycloaddition is found to be the rate-determining step. Calculated rate constants confirm the latest experimental data.
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Dai, Qian y Hua Ye Guan. "A New Skeletal Chemical Kinetic Mechanism of Ethanol Combustion for HCCI Engine Simulation". Advanced Materials Research 614-615 (diciembre de 2012): 381–84. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.381.
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According to the detailed chemical kinetic mechanism of ethanol proposed by the U．S．Lawrence Livermore Laboratory, this paper analyzes the main approach of ethanol oxidation. Based on the detailed chemical kinetics mechanism, a skeletal chemical reaction mechanism is presented by reaction path analysis．Thus a simplified model is constructed, which consists of 26 species and 26 reactions．And then the comparative studies were given between the simplified model and the detailed model．The simulation results show that simplified model and detailed model have good consistency.
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Keddam, Mourad, Polat Topuz y Özlem Aydin. "Simulation of boronizing kinetics of AISI 316 steel with an integral diffusion model". Materials Testing 63, n.º 10 (1 de octubre de 2021): 906–12. http://dx.doi.org/10.1515/mt-2021-0023.
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Abstract Boriding or boronizing is a type of surface property improvement process applied to metal or some non-metal materials by diffusion. The calculation of diffusion kinetics is also very important as it is a diffusion controlled process. Today, many researchers perform kinetic calculations by applying the Second Fick’s law to the Arrhenius equation. In this study, as an alternative to conventional kinetic calculations, the mathematical modeling of diffusion kinetics has been performed using the integral diffusion model. For the boronizing experiments, the pack-boronizing method was chosen and AISI 316 austenitic stainless steel was used. The experiments were carried out at three temperatures and for three times; Ekabor 2 was used as the boronizing agent. The detailed diffusion kinetics calculations were made using the data obtained from the experiments in the mathematical modeling.
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BROUWER, J., G. SACCHI, J. P. LONGWELL y A. F. SAROFIM. "A Turbulent Reacting Flow Model that Incorporates Detailed Chemical Kinetics". Combustion Science and Technology 101, n.º 1-6 (noviembre de 1994): 361–82. http://dx.doi.org/10.1080/00102209408951883.
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Huebner, W. F., D. C. Boice, I. Konno y P. D. Singh. "A Model of P/Tempel 2 With Dust and Detailed Chemistry". Symposium - International Astronomical Union 150 (1992): 449–50. http://dx.doi.org/10.1017/s0074180900090665.
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Pannala, Venkat R., Amadou K. S. Camara y Ranjan K. Dash. "Modeling the detailed kinetics of mitochondrial cytochrome c oxidase: Catalytic mechanism and nitric oxide inhibition". Journal of Applied Physiology 121, n.º 5 (1 de noviembre de 2016): 1196–207. http://dx.doi.org/10.1152/japplphysiol.00524.2016.
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Cytochrome c oxidase (CcO) catalyzes the exothermic reduction of O2 to H2O by using electrons from cytochrome c, and hence plays a crucial role in ATP production. Although details on the enzyme structure and redox centers involved in O2 reduction have been known, there still remains a considerable ambiguity on its mechanism of action, e.g., the number of sequential electrons donated to O2 in each catalytic step, the sites of protonation and proton pumping, and nitric oxide (NO) inhibition mechanism. In this work, we developed a thermodynamically constrained mechanistic mathematical model for the catalytic action of CcO based on available kinetic data. The model considers a minimal number of redox centers on CcO and couples electron transfer and proton pumping driven by proton motive force (PMF), and accounts for the inhibitory effects of NO on the reaction kinetics. The model is able to fit well all the available kinetic data under diverse experimental conditions with a physiologically realistic unique parameter set. The model predictions show that: 1) the apparent Km of O2 varies considerably and increases from fully reduced to fully oxidized cytochrome c depending on pH and the energy state of mitochondria, and 2) the intermediate enzyme states depend on pH and cytochrome c redox fraction and play a central role in coupling mitochondrial respiration to PMF. The developed CcO model can easily be integrated into existing mitochondrial bioenergetics models to understand the role of the enzyme in controlling oxidative phosphorylation in normal and disease conditions.
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Fiçicilar, Berker, İnci Eroğlu y Trung V. Nguyen. "A Five Layer One-Dimensional PEMFC Model with Detailed Electrode Kinetics". ECS Transactions 33, n.º 1 (17 de diciembre de 2019): 1515–27. http://dx.doi.org/10.1149/1.3484644.
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Dandy, David S. y Michael E. Coltrin. "A simplified analytical model of diamond growth in direct current arcjet reactors". Journal of Materials Research 10, n.º 8 (agosto de 1995): 1993–2010. http://dx.doi.org/10.1557/jmr.1995.1993.
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A simplified model of a direct current arcjet-assisted diamond chemical vapor deposition reactor is presented. The model is based upon detailed theoretical analysis of the transport and chemical processes occurring during diamond deposition, and is formulated to yield closed-form solutions for diamond growth rate, defect density, and heat flux to the substrate. In a direct current arcjet reactor there is a natural division of the physical system into four characteristic domains: plasma torch, free stream, boundary layer, and surface, leading to the development of simplified thermodynamic, transport, and chemical kinetic models for each of the four regions. The models for these four regions are linked to form a single unified model. For a relatively wide range of reactor operating conditions, this simplified model yields results that are in good quantitative agreement with stagnation flow models containing detailed multicomponent transport and chemical kinetics. However, in contrast to the detailed reactor models, the model presented here executes in near real-time on a computer of modest size, and can therefore be readily incorporated into process control models or global dynamic loop simulations.
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Kukshinov, N. V., S. N. Batura y M. S. Frantsuzov. "Validation of Methods for Calculating Hydrogen Combustion in a Supersonic Model Air Flow Using the Experimental Data of Beach — Evans — Schexnayder". Proceedings of Higher Educational Institutions. Маchine Building, n.º 11 (716) (noviembre de 2019): 36–45. http://dx.doi.org/10.18698/0536-1044-2019-11-36-45.
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This paper deals with numerical simulation of combustion of a hydrogen-air mixture in a supersonic flow. The simulation is based on solving the complete system of Navier-Stokes equations with closure using the turbulence model and detailed chemical kinetics. The mixing and combustion of a hydrogen-air fuel mixture is considered in the experimental formulation of Beach-Evans-Schexnayder. The effect of various kinetic mechanisms, turbulence models, TCI models, and boundary conditions on the solution is studied qualitatively and quantitatively. The relative errors of mass concentration of water for control sections are determined, and the methods’ boundaries are shown. Conclusions are drawn on the influence of turbulent mixing mechanisms and chemical kinetics on the combustion of hydrogen.
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Zhang, Pei, Siyan Liu, Dan Lu, Ramanan Sankaran y Guannan Zhang. "An out-of-distribution-aware autoencoder model for reduced chemical kinetics". Discrete & Continuous Dynamical Systems - S 15, n.º 4 (2022): 913. http://dx.doi.org/10.3934/dcdss.2021138.
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<p style='text-indent:20px;'>While detailed chemical kinetic models have been successful in representing rates of chemical reactions in continuum scale computational fluid dynamics (CFD) simulations, applying the models in simulations for engineering device conditions is computationally prohibitive. To reduce the cost, data-driven methods, e.g., autoencoders, have been used to construct reduced chemical kinetic models for CFD simulations. Despite their success, data-driven methods rely heavily on training data sets and can be unreliable when used in out-of-distribution (OOD) regions (i.e., when extrapolating outside of the training set). In this paper, we present an enhanced autoencoder model for combustion chemical kinetics with uncertainty quantification to enable the detection of model usage in OOD regions, and thereby creating an OOD-aware autoencoder model that contributes to more robust CFD simulations of reacting flows. We first demonstrate the effectiveness of the method in OOD detection in two well-known datasets, MNIST and Fashion-MNIST, in comparison with the deep ensemble method, and then present the OOD-aware autoencoder for reduced chemistry model in syngas combustion.</p>
Tesis sobre el tema "Detailed kinetics model"
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Davidson, Jeffrey E. "Combustion Modeling of RDX, HMX and GAP with Detailed Kinetics". BYU ScholarsArchive, 1996. https://scholarsarchive.byu.edu/etd/6531.
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A one-dimensional, steady-state numerical model of the combustion of homogeneous solid propellant has been developed. The combustion processes is modeled in three regions: solid, two-phase (liquid and gas) and gas. Conservation of energy and mass equations are solved in the two-phase and gas regions and the eigenvalue of the system (the mass burning rate) is converged by matching the heat flux at the interface of these two regions. The chemical reactions of the system are modeled using a global kinetic mechanism in the two-phase region and an elementary kinetic mechanism in the gas region. The model has been applied to RDX, HMX and GAP. There is very reasonable agreement between experimental data and model predictions for burning rate, temperature sensitivity, surface temperature, adiabatic flame temperature, species concentration profiles and melt-layer thickness. Many of the similarities and differences in the combustion of RDX and HMX are explained from sensitivity analysis results. The combustion characteristics of RDX and HMX are similar because of their similar chemistry. Differences in combustion characteristics arise due to differences in melting temperature, vapor pressure and initial decomposition steps. A reduced mechanism consisting of 18 species and 39 reactions was developed from the Melius-Yetter RDX mechanism (45 species, 232 reactions). This reduced mechanism reproduces most of the predictions of the full mechanism but is 7.5 times faster. Because of lack of concrete thermophysical property data for GAP, the modeling results are preliminary but indicate what type of experimental data is necessary before GAP can be modeled with more certainty.
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Park, Sung-Woo. "Detailed chemical kinetic model for oxygenated fuels". Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9599.
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A detailed chemical kinetic model is developed and tested for the combustion of C2 and C3 oxygenated fuels such as ethanol, DME (dimethyl ether), acetone and n-propanol. It is validated by comparing predictions with experimental data on the structure of low pressure burner stabilised premixed flames and laminar burning velocities over a wide range of equivalence ratios. Data from shock tube and stirred reactor studies has also been considered. The elementary reactions of ethanol and DME oxidation have been studied extensively and were used as a starting point for extension to C3 oxygenated fuels. The chemistry of acetylene which is one of major intermediate species in higher hydrocarbon flames was also updated to improve the reliability of the present mechanism and acetylene laminar burning velocities and low-pressure premixed lean and rich flames were also computed. The detailed mechanism features more than 1500 reaction steps and 269 species. The structure of laminar premixed flames are predicted by using measured temperature profiles and conditions cover fuel-lean and fuel-rich mixtures at low pressure. The profiles of reactants, products and major intermediate species are compared to experimental data from mass spectrometry and the overall agreement between the kinetic model and experimental data is satisfactory. An analytic study of fuel consumption pathways is carried out to understand the detailed consumption pathways. The present mechanism is also tested against laminar flame speeds by calculating freely propagating premixed flames to extend the understanding of the combustion characteristics of oxygenated fuels. A sensitivity analysis is also performed.
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Maurice, Lourdes Quintana. "Detailed chemical kinetic models for aviation fuels". Thesis, Imperial College London, 1996. http://hdl.handle.net/10044/1/8153.
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Adams, Waldo Wayne. "Glycerol production in plasmodium falciparum : towards a detailed kinetic model". Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97159.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Having caused the deaths of more than 10 million individuals since 2000 with most of them occurring in Africa, malaria remains a serious disease that requires undivided attention. To this end a detailed kinetic model of Plasmodium falciparum glycolysis was constructed, validated and used to determine potential drug targets for the development of novel, effective antimalarial therapies. The kinetic model described the behaviour of the glycolytic enzymes with a set of ordinary differential equations that was solved to obtain the steady state fluxes and concentrations of internal metabolites. The model included a glycerol branch represented in a single fitted equation. This present study set out to detect, characterise, and incorporate into the model the enzymes that constitute the glycerol branch of P. falciparum glycolysis. The kinetic parameters of glycerol 3-phosphate dehydrogenase (G3PDH), the first enzyme in the branch and catalyst of the dihydroxyacetone phosphosate (DHAP) reducing reaction, was determined and added to the detailed kinetic model. The model was subsequently validated by comparing its prediction of steady state fluxes with experimentally measured fluxes. Once it was evident that the predictions of the unfitted model agreed with experimentally measured fluxes, metabolic control analysis was performed on this branched system to ascertain the distribution of control over the steady state flux through the glycerol branch. The control G3PDH exercised over its own flux was less than expected due to the enzyme’s sensitivity to changes in NADH and thus the redox balance of the cell. Attempts were made to detect the enzymes responsible for the conversion of glycerol 3-phosphate (G3P) to glycerol. Very low levels of glycerol kinase activity was observed. Although G3P-dependent release of inorganic phosphate was detected results were inconclusive as to whether a non-specific phosphatase also mediated the conversion. Overall, the expansion of the model to include G3PDH did not affect the steady state metabolite concentrations and flux adversely.
AFRIKAANSE OPSOMMING: Vanaf die jaar 2000 het malaria die dood van meer as 10 miljoen mense veroorsaak. Die meeste sterftes het in Afrika voorgekom —’n aanduiding van hoe ernstige siekte dit is en een wat onverdeelde aandag moet geniet. Om hierdie rede is ’n gedetaileerde kinetiese model van glikoliese in Plasmodium falciparum gebou, gevalideer en gebruik om potensiële dwelm teikens te identifiseer vir die ontwikkeling van nuwe, meer effektiewe anti-malaria terapieë. Die kinetiese model beskryf die gedrag van die glikolitiese ensieme in terme van gewone differensiële vergelykings wat opgelos is om die bestendige toestand fluksies en interne metaboliet konsentrasies te bepaal. Die model sluit ’n gliserol-tak in wat deur ’n enkele aangepaste vergelyking verteenwoordig word. Hierdie studie het voorgeneem om die ensieme van die gliserol-tak van P. falciparum glikoliese te identifiseer, karakteriseer en in die model te inkorporeer. Ons het die kinetiese parameters van die eerste ensiem in die gliserol-tak, gliserol 3-fosfaat dehidrogenase (G3PDH), die katalis van die dihidroksiasetoon fosfaat(DHAP) reduserende reaksie, bepaal. Die kinetiese parameters is by die gedetaileerde model gevoeg. Validering het plaasgevind deur die model se voorspellings met eksperimenteel bepaalde waardes te vergelyk. Toe dit duidelik geword het dat die voorspellings van die model met die eksperimenteel bepaalde fluks ooreenstem, is metaboliese kontrole analiese op die vertakte sisteem uitgevoer. Dit is gedoen om vas te stel hoe die bestendige toestand fluks deur die gliserol-tak beheer word. G3PDH het nie volle beheer oor sy eie fluks nie, in teenstelling met ons vergewagtinge. Daar is gepoog om vas te stel watter ensieme verantwoordelik is vir die produksie van gliserol vanuit gliserol 3-fosfaat (G3P). ’n Lae gliserolkinase aktiwiteit is waargeneem. Alhoewel G3P afhanklike vrystelling van anorganise fosfaat waargeneem is, is dit nie duidelik vanuit die resultate of die proses deur ’n nie-spesifieke fosfatase uitgevoer word nie. Die uitbreiding van die model om ’n G3PDH vergelyking in te sluit het nie die bestendige toestand metaboliet konsentrasies en fluks negatief geaffekteer nie.
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Honnet, Sylvie. "Detailed and reduced kinetic mechanisms in low-emission combustion processes /". Göttingen : Cuvillier, 2007. http://d-nb.info/98605528X/04.
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Du, Preez Franco B. "Comparative cross-species analysis of detailed kinetic models of glycolysis". Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1208.
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Thesis (PhD (Biochemistry))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: With the recent advances in the field of molecular biology, there is an increased need to integrate data on the various constituents of the cell in kinetic models that can predict and describe cellular behavior. When working towards a description of the entire cell using such kinetic models, the question arises: How do we compare different models for a given biological network? This is the central question addressed in my thesis and I developed and applied mathematical and computational methods for comparing dozens of existing models of erythrocyte and yeast glycolysis. To compare the steady-state behavior in models of erythrocyte glycolysis, I focussed on the function of the pathway, which is to supply the cell with Gibbs-free energy (γ- phosphate of ATP). I used supply-demand analysis in the framework of metabolic control analysis to make this comparison, which revealed that the ATP concentrations were homeostatically buffered at varying supply rates. I also applied this approach to compare steady-state behavior in models of yeast glycolysis, finding that they were not necessarily optimized for homeostatic maintenance of the ATP concentration and that in models for this organism the rate of ATP production is often determined by the supply reactions of glycolysis. In addition, I tested whether a kinetic model can describe novel behavior if it is adjusted to conditions different from those for which the model was originally constructed. More specifically, using a model of steady-state yeast glycolysis, I showed that small adjustments to the original enzyme concentrations are enough to obtain an oscillating model, which shows a remarkable resemblance to the experimentally observed oscillations. Importantly, some of these enzyme concentrations changes are known to occur during the pre-treatment of the cells which is necessary to obtain oscillatory behavior. To the best of my knowledge, the resulting model is the first detailed kinetic model that describes the experimentally observed strong synchronization of glycolytic oscillations in yeast populations. To analyze the dynamic behavior of yeast glycolytic models and to compare different models in terms of dynamics, I introduced a framework used in physics and engineering to create a vector based, two dimensional graphical representation of the oscillating metabolites and reactions of glycolysis. Not only was it possible to make a concise comparison of the set of models, but with the method I could also quantify the contribution of the interactions in the network to the transduction of the oscillations. Furthermore I could distinguish between different mechanisms of oscillation for each of the models, and demonstrated how the framework can be used to create such representations for experimental data sets.
AFRIKAANSE OPSOMMING: Met die onlangse vooruitgang in die veld van molekulere biologie, is daar ?n toenemende behoefte om data rakende die verskeie komponente van die sel in kinetiese modelle te integreer, om sodanig selgedrag te voorspel en te beskryf. As daar gepoog word om ’n beskrywing van die sel as geheel te verkry d.m.v. sulke kinetiese modelle, onstaan die vraag: Hoe vergelyk ons verskillende modelle van ’n gegewe biologiese netwerk? Dit is die sentrale vraag wat my tesis aanspreek en ek het wiskundige en numeriese metodes ontwikkel en toegepas om talle bestaande modelle van gis- en eritrosietglikolise te vergelyk. Om die bestendige-toestand gedrag in modelle van eritrosietglikolise te vergelyk, het ek gefokus op die funksie van die padweg, naamlik om die sel met Gibbs-vrye energie (γ-fosfaat van ATP) te voorsien. Ek het vraag-aanbod analiese in die raamwerk van metaboliese kontrole analiese gebruik om hierdie vergelyking te maak, wat getoon het dat die ATP konsentrasies homeostaties gebuffer was by verskillende aanbod tempos. Ek het ook hierdie aanpak gebruik om die bestendige-toestand gedrag in modelle van gisglikolise te vergelyk, en het bevind dat hulle nie noodwendig geoptimiseer is om ?n homeostatiese balans in die ATP konsentrasie te handhaaf nie, en dat in modelle vir hierdie organisme, die tempo van ATP produksie dikwels bepaal word deur die aanbod reaksies van glikoliese. Ek het verder ook bepaal of so ?n kinetiese model nuwe soorte gedrag kan beskryf, as dit aangepas word aan omstandighede wat verskil van dié waarvoor die model oorspronklik gekonstrueer was. Meer spesifiek, deur ?n model van bestendige-toestand gisglikolise te gebruik, kon ek wys dat klein veranderinge aan die oorspronkline ensiem konsentrasies genoeg was om ?n ossilerende model te verkry, wat opmerklik ooreenstem met die eksperimenteel waargenome ossilasies. Let ook daarop dat sommige van hierdie ensiem konsentrasie veranderinge plaasvind tydens die voorafbehandeling van die selle, wat essensieel is om die ossilasies waar te neem. Tot die beste van my kennis is die model wat ek met hierdie prosedures verkry het, die eerste gedetaileerde kinetiese model wat die eksperimenteel waargenome sterk sinkronisasie in ossilerende gis populasies voorspel. Om gis glikolitiese modelle te vergelyk in terme van hul dinamiese gedrag, het ek ?n raamwerk wat in fisika en ingeneurswese gebruik word, ingespan om ?n vektor-gebasseerde, twee dimensionele grafiese voorstelling van die ossilerende metaboliete en reaksies te maak. Hierdie raamwerk het dit nie net moontlik gemaak om ?n kompakte vergelyking van ?n stel modelle te maak nie, maar ek kon ook die bydrae van interaksies in die netwerk tot transduksie van die ossilasies kwantifiseer. Ek kon verder onderskeid tref tussen die verskillende ossilasiemeganismes vir elk van die modelle, en het ook gedemonstreer hoe die raamwerk gebruik kan word om sulke voorstellings vir eksperimentele datastelle te skep.
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Penkler, Gerald Patrick. "Construction and validation of a detailed kinetic model of glycolysis in asexual Plasmodium falciparum : a feasibility study". Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2298.
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Thesis (MSc (Biochemistry))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: In Africa alone, Plasmodium, the causative agent of malaria is estimated to kill a child, under the age of five every thirty seconds140. The ability of the parasite to rapidly attain resistance, has resulted in immunity of the parasite to all, except one group of frontline drugs. The need to develop novel drugs, vaccines and prevention strategies that are accessible and affordable for third world countries is of the utmost importance to prevent needless human suffering and death. The glycolytic pathway is an attractive drug target since it is the principal source of ATP for the parasite. Many of the glycolytic enzymes have been studied and proposed as drug targets, but the importance of these enzymes for the function of the pathway as a whole has not been considered. It is known, from the frameworks of metabolic control analysis, that control of the flux and metabolite concentration can be divided among the individual steps. Differential control analysis of Plasmodium and erythrocyte glycolysis may reveal potential drug targets. These analyses require a detailed kinetic model of Plasmodium glycolysis, and the feasibility of constructing and validating such a model was the aim of this study. In this work we determined the feasibility of constructing and validating a detailed kinetic model for the Plasmodium falciparum glycolytic pathway. Whether the construction and validation of this kinetic model was feasible or not was decided on the basis of the ability to: i) culture and isolate sufficient asexual parasites for enzymatic and steady state assays , ii) obtain kinetic parameters such as Km and Vmax for each glycolytic enzyme, either from literature or experimentally, iii) measure glycolytic fluxes, iv) determine glycolytic intermediate concentrations, v) construct a kinetic model from the kinetic parameters and vi) validate it with steady state glycolytic fluxes and metabolite concentrations Each of the above criteria were successfully addressed. In summary, the kinetic parameters and glycolytic fluxes that were measured experimentally, were used to construct and partially validate a detailed kinetic model, respectively. Further validation of the model by means of steady state metabolite concentrations was shown to be possible with the development of a suitable protocol to measure the glycolytic intermediate concentrations. The model presented in this work may play an important role in drug target identification and improving the current understanding of host-parasite interactions and glycolytic regulation.
AFRIKAANSE OPSOMMING: Plasmodium, die parasiet wat malaria veroorsaak, is in Afrika alleen elke dertig sekondes verantwoordelik vir die afsterwe van ’n kind jonger as vyf jaar. Die parasiet se vermoë om vinnig weerstand op te bou het daartoe gelei dat Plasmodium weerstandbiedend is teen byna alle nuwe teen-malaria middels, behalwe vir ’n enkele toonaangewende groep. Die ontwikkeling van nuwe malaria teen-middels is van uiterste belang om lyding te voorkom. ’n Goeie teiken vir teen-malaria middels is die glikolitiese padweg omdat die metaboliese padweg essensieël is vir die produksie van ATP, die energiebron van die parasiet. Desondanks die feit dat meeste van die glikolitiese ensieme al goed bestudeer en as teiken voorgestel is, is dit steeds onduidelik hoe hierdie ensieme saam funksioneer om die metaboliese weg, as geheel, tot stand te bring. Metaboliese kontrole analise het aangetoon dat die glikolitiese beheer verdeel is tussen die onderskeie glikolitiese ensieme, m.a.w. geen enkele ensiematiese stap het volledige beheer oor die fluksie van die glikolitiese padweg nie. Die afsonderlike analise en vergelyking van Plasmodium - en rooibloedselglikolise met behulp van differensiële metaboliese kontrole analise sal moontlik gebruik kan word om gasheervriendelike teikens vir nuwe middels aan te toon. So ’n analise benodig ’n omvattende kinetiese model van Plasmodium glikolise. Derhalwe was die doel van hierdie studie om vas te stel hoe uitvoerbaar dit is om ’n kinetiese model van Plasmodium glikolise te konstrueer en te valideer. Die uitvoerbaarheid van die konstruksie en validering van die kinetiese model was geasseseer op grond van die vermoë om: i) parasietkulture te kweek en genoegsame parasiete, wat in die aseksuele fase is, te isoleer sodat ensiembepalings en bestendige toestand-bepalings gedoen kan word, ii) kinetiese parameters soos Km - en Vmax-waardes vir elke glikolitiese ensiem, hetsy vanuit literatuur of eksperimentele werk, te verkry, iii) glikolitiese fluksie te meet, iv) glikolitiese intermediaatkonsentrasies te bepaal, v) ’n kinetiese model van die bepaalde kinetiese parameters op te stel en vi) die model te valideer met glikolitiese flukswaardes en metaboliet- konsentrasies wat in die bestendige toestand verkry is. Elk van die bogenoemde kriteria was met sukses in hierdie studie aangespreek. Ter opsomming, die eksperimenteel bepaalde kinetiese parameters en glikolietiese flukswaardes was gebruik om onderskeidelik ’n gedetaileerde kinetiese model te konstrueer en gedeeltelik te valideer. Daar was getoon dat verdere validering van die model deur middel van bestendige toestand metabolietkonsentrasies moontlik is met die ontwikkeling van ’n geskikte protokol om glikolitiese intermediaatkonsentrasies te meet. Die model, soos opgestel in hierdie studie, kan moontlik ’n belangrike rol speel om teikens vir nuwe malaria teen-middels te identifiseer en om gasheer-parasiet interaksies en glikolitiese regulering beter te verstaan.
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Savage, Nicholas. "The use of a modified IQT™ apparatus and detailed chemical kinetic model to investigate the atmospheric autoignition characteristics of model fuels". Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/5474.
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KONOPKA, THIAGO FABRICIUS. "COMPARATIVE STUDY OF DETAILED CHEMICAL KINETIC MODELS OF SOOT PRECURSORS FOR ETHYLENE/AIR AND METHANE/AIR COMBUSTION". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23399@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROEssa dissertação apresenta um estudo comparativo de quatro diferentes modelos de cinética química detalhada que envolvem as principais espécies químicas responsáveis pelo processo de formação e oxidação da fuligem, i.e., o oxigênio molecular, o radical hidroxila, o acetileno, o propargil, benzeno, fenil e pireno. Para este fim, considera-se a combustão de misturas de etileno/ar e metao/ar. Para analisar os modelos cinéticos são utilizados um reator perfeitamente misturado (PSR) e um reator parcialmente misturado (PaSR). No caso do reator perfeitamente misturado, um estudo sistemático da influência do tempo de residência e a riqueza da mistura sobre estas espécies químicas é apresentado. São discutidas as importantes discrepâncias obtidas, para o acetileno, o propargil, o benzeno, o fenil e o pireno, entre os modelos cinéticos analisados. As espécies oxidantes exibem menores discrepâncias dentre todas as espécies analisadas. No caso do reator parcialmente misturado, a razão entre o tempo de residência e o tempo de mistura é o parâmetro de análise. De modo geral, os resultados obtidos permitem avaliar o comportamento dos mecanismos cinéticos em uma situação representativa de combustão em escoamentos turbulentos.
In this dissertation a comparative study is presented of four different detailed kinetics models involving the main chemical species responsible for the soot formation and oxidation, i.e., the molecular oxygen, the hydroxyl, the acetylene, the propargyl, the benzene and the pyrene. To this purpose is considered the combustion of ethylene/air and metane/air. To analyze the kinetic models are used a perfect stirred reactor (PSR) and a partial stirred reactor (PaSR). In the case of a perfect stirred reactor a systematic study of the influence of the residence time and of the equivalence ratio on these chemical species is presented. Are discussed the important discrepancies obtained for acetylene, propargyl, benzene, phenyl and pyrene, between the kinetic models analyzed. The oxidizing species exhibit minor discrepancies only. In the case of the partially mixed reactor, the ratio between the residence time and the mixing time is the analysis parameter. Overall, the results obtained allow to evaluate the behavior of the kinetic mechanisms in situations representative of combustion in turbulent flows.
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Calisesi, Federico. "The analysis of the injection of hydrogen-oxygen mixtures in gasoline-powered internal combustion engines". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15553/.
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The effects on combustion derived by the blending of hydrogen with traditional fuels adopted for internal combustion engines have been studied. Results derived by emission tests of a gasoline-fed vehicle equipped with a system for the production of hydrogen on-board have been analysed. The energy balance for the engine was evaluated. It demonstrated the increase of fuel consumptions to perform electrolysis process on-board the vehicle. Afterwards, numerical simulations based on a detailed kinetic model have been performed to calculate pollutant emissions produced by methane and iso-octane (which represents gasoline) compared with a mixture composed of 10% mol/mol by hydrogen. Chemical species studied were residual hydrocarbons, nitrous oxides and carbon monoxide. Notable variations of pollutant has not been calculated for methane, wherease iso-octane showed a reduction of the aforementioned pollutants when hydrogen was introduced. In the end operating costs have been analysed. The use of stored hydrogen produced by methane steam reforming found a reduction by 7% of costs, compared to the production via electrolysis.
Libros sobre el tema "Detailed kinetics model"
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Battin-Leclerc, Frédérique, John M. Simmie y Edward Blurock. Cleaner Combustion: Developing Detailed Chemical Kinetic Models. Springer, 2013.
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Simmie, John M., Edward Blurock y édérique Battin-Leclerc. Cleaner Combustion: Developing Detailed Chemical Kinetic Models. Springer London, Limited, 2013.
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Battin-Leclerc, Frédérique, John M. Simmie y Edward Blurock. Cleaner Combustion: Developing Detailed Chemical Kinetic Models. Springer, 2016.
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Chappell, Michael, Bradley MacIntosh y Thomas Okell. Introduction. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198793816.003.0001.
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This chapter details the widely accepted standard approach to arterial spin labeling (ASL) acquisition and the associated analysis needed to extract an image of perfusion in the brain, also known as the cerebral blood flow (CBF). Starting with pairs of images with and without labeling, a perfusion-weighted image can be generated. With the addition of a calibration image, this can be converted to an absolute measure of perfusion. Following the recommendations of the community for ASL acquisition, this chapter outlines the main steps of subtraction, kinetic model inversion, and calibration required for analysis of ASL data.
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Zaitsev, Fedor y Vladimir Bychkov. Mathematical modeling of electromag-netic and gravitational phenomena by the methodology of continuous media mechanics. LCC MAKS Press, 2021. http://dx.doi.org/10.29003/m2011.978-5-317-06604-8.
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The book of well-known Russian scientists systematically presents a new theoretical approach to studying nature's fundamental phenomena using the hypothesis of the physical vacuum, or the ether, as some environment in which all the processes develop. In the proposed studies, the ether is represented as some one-component continuous media that satisfies generally accepted conservation laws: of matter and momentum. From the appropriate two equations, a number of consequences are obtained to which a physical interpretation is given. For the first time, 150 years after studies of Faraday and Maxwell, it is shown that these single premises mathematically give basic physical laws established experimentally: the Maxwell equations, the Lorentz force, the Gauss theorem; the laws: Coulomb, Biot - Savard, Ampere, electromagnetic induction, Ohm, Joule - Lenz, Wiedemann - Franz, universal gravitation, and etc. Details of mechanisms of many processes, that seemed previously paradoxical, have been disclosed. A method of the model substantiation adopted in the mathematical modeling methodology allows to conclude that the presented mathematical model of the ether adequately describes electromagnetic and gravitational processes. Qualitative and quantitative analysis of hundreds of known and new experimental facts allows in the methodology of physics, as science summarizing the experiments data, to confirm a conclusion about the existence of the ether (physical vacuum). The content of the book is based on the works of authors done during the last fourteen years. Many results are published for the first time. The book is intended for specialists in the field of electrodynamics, electrical engineering, gravity and kinetics, as well as for graduate students and students, interested in the fundamental principles of these scientific directions. This book is unique in terms of the comprehensive consideration of the problem and the depth of its analysis.
Capítulos de libros sobre el tema "Detailed kinetics model"
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Zhao, Peng. "Detailed Kinetics in Combustion Simulation: Manifestation, Model Reduction, and Computational Diagnostics". En Energy, Environment, and Sustainability, 45–71. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-7410-3_2.
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Rebosio, F., A. Widenhorn, B. Noll y M. Aigner. "Analysis of the Effects of Wall Boundary Conditions and Detailed Kinetics on the Simulation of a Gas Turbine Model Combustor Under Very Lean Conditions". En High Performance Computing in Science and Engineering '11, 229–43. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-23869-7_18.
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Battin-Leclerc, Frédérique, Henry Curran, Tiziano Faravelli y Pierre A. Glaude. "Specificities Related to Detailed Kinetic Models for the Combustion of Oxygenated Fuels Components". En Cleaner Combustion, 93–109. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-5307-8_4.
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Totis, Niccolò, Andrea Tagherloni, Marco Beccuti, Paolo Cazzaniga, Marco S. Nobile, Daniela Besozzi, Marzio Pennisi y Francesco Pappalardo. "Efficient and Settings-Free Calibration of Detailed Kinetic Metabolic Models with Enzyme Isoforms Characterization". En Computational Intelligence Methods for Bioinformatics and Biostatistics, 187–202. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-34585-3_17.
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Carstensen, Hans-Heinrich y Anthony M. Dean. "Development of Detailed Kinetic Models for the Thermal Conversion of Biomass via First Principle Methods and Rate Estimation Rules". En ACS Symposium Series, 201–43. Washington, DC: American Chemical Society, 2010. http://dx.doi.org/10.1021/bk-2010-1052.ch010.
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Grana, R., S. Sommariva, T. Maffei, A. Cuoci, T. Faravelli, A. Frassoldati, S. Pierucci y E. Ranzi. "Detailed kinetics in the mathematical model of fixed bed gasifiers". En Computer Aided Chemical Engineering, 829–34. Elsevier, 2010. http://dx.doi.org/10.1016/s1570-7946(10)28139-7.
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Arshad, Muzammil. "Numerical Simulations and Validation of Engine Performance Parameters Using Chemical Kinetics". En Numerical Simulation [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106536.
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Use of detailed chemistry augments the combustion model of a three-dimensional unsteady compressible turbulent Navier–Stokes solver with liquid spray injection when coupled with fluid mechanics solution with detailed kinetic reactions. Reduced chemical reaction mechanisms help in the reducing the simulations time to study of the engine performance parameters, such as, in-cylinder pressure in spark ignition engines. Sensitivity analysis must be performed to reduce the reaction mechanism for the compression and power strokes utilizing computational singular perturbation (CSP) method. To study a suitable well-established surrogate fuel, an interface between fluid dynamics and chemical kinetics codes must be used. A mesh independent study must be followed to validate results obtained from numerical simulations against the experimental data. To obtain comprehensive results, a detailed study should be performed for all ranges of equivalence ratios as well as stoichiometric condition. This gives rise to the development of a reduced mechanism that has the capability to validate engine performance parameters from stoichiometric to rich mixtures in a spark ignition engine. The above-mentioned detailed methodology was developed and implemented in the present study for premixed and direct injection spark ignition engines which resulted in a single reduced reaction mechanism that validated the engine performance parameters for both engine configurations.
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Fawcett, W. Ronald. "Chemical Reaction Kinetics in Solution". En Liquids, Solutions, and Interfaces. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195094329.003.0011.
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The kinetics of chemical reactions were first studied in liquid solutions. These experiments involved mixing two liquids and following the change in the concentration of a reactant or product with time. The concentration was monitored by removing a small sample of the solution and stopping the reaction, for example, by rapidly lowering the temperature, or by following a physical property of the system in situ, for example, its color. Although the experiments were initially limited to slow reactions, they established the basic laws governing the rate at which chemical changes occur. The variables considered included the concentrations of the reactants and of the products, the temperature, and the pressure. Thus, the reacting system was examined using the variables normally considered for a system at equilibrium. Most reactions were found to be complex, that is, to be made up of several elementary steps which involved one or two reactants. As the fundamental concepts of chemical kinetics developed, there was a strong interest in studying chemical reactions in the gas phase. At low pressures the reacting molecules in a gaseous solution are far from one another, and the theoretical description of equilibrium thermodynamic properties was well developed. Thus, the kinetic theory of gases and collision processes was applied first to construct a model for chemical reaction kinetics. This was followed by transition state theory and a more detailed understanding of elementary reactions on the basis of quantum mechanics. Eventually, these concepts were applied to reactions in liquid solutions with consideration of the role of the non-reacting medium, that is, the solvent. An important turning point in reaction kinetics was the development of experimental techniques for studying fast reactions in solution. The first of these was based on flow techniques and extended the time range over which chemical changes could be observed from a few seconds down to a few milliseconds. This was followed by the development of a variety of relaxation techniques, including the temperature jump, pressure jump, and electrical field jump methods. In this way, the time for experimental observation was extended below the nanosecond range.
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Banerjee, Diptonil, Amit Kumar Sharma y Nirmalya Sankar Das. "Removal of Dyes by the Process of Adsorption". En Nano Materials Induced Removal of Textile Dyes from Waste Water, 232–66. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815050295122010009.
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Adsorption is one of the simplest ways and means to remove dyes from water. The process of adsorption simply involves the removal of water contaminants that come in contact with adsorbents, i.e., the materials of interest. The material should only have sufficient surface area, porosity, and adequate numbers of adsorption sites. Besides being one of the simplest means of dye removal, the process has further advantages in that the same material may be used many times, i.e., regarding the recyclability of the material. Keeping all these in mind in this chapter, a detailed discussion regarding the adsorption process has been included. The discussion not only covers the basic principle of the process but also unfolds the analysis technique regarding the performance of certain material as an efficient absorber. The quantification of removal efficiency will also be a topic of discussion. The setup for such a kind of measurement will be unveiled, and most importantly, different theoretical models for such a process will also be a topic of interest in this chapter. The different models include the Langmuir model, Freundlich model, Temkin model, and others. An effort has also been made to enlighten the readers with the different reaction kinetics like pseudo-first-order, or second-order reaction kinetics. In every subsection, a few experimental data will be shown and discussed.
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Morishima, Isao. "Pressure Effects on the Ligand-Binding Kinetics for Hemoproteins and Their Site-Directed Mutants". En High Pressure Effects in Molecular Biophysics and Enzymology. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195097221.003.0016.
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The effects of high pressure up to 1500 bar on the recombination kinetics of oxygen and carbon monoxide (CO) binding to human hemoglobin (intact and isolated chain forms), human myoglobin (and its mutants), and cytochrome P-450 were studied by the use of millisecond and nanosecond laser photolysis. The activation volumes for the binding of CO to the R- and T-quaternary states of hemoglobin (Hbs) were determined to be –9.0 and –31.7 ml, respectively. The characteristic pressure dependence of the activation volume was observed for the R-state Hb but not for the T-state Hb. More detailed studies were made with isolated α- and β-chains of human Hb. The kinetic data were analyzed on the basis of a simple three-species model, which assumes two elementary reaction processes of bond formation and steps of ligand migration. A pressure-dependent activation volume change from negative lo positive values in the bimolecular CO association reaction was observed for both chains. This is attributed to a change of the rate-limiting step from the bond-formation step to the ligandmigration step. High-pressure ligand-binding kinetics were also examined for site-specific mutants of human myoglobin in which some amino acid residues at the heme distal sites, such as Leu 29, Lys 45, Ala 66, and Thr 67, are substituted by others. The pressure dependence of the CO binding rate for the L29 mutants was unusual: a positive value was obtained unexpectedly for overall CO binding. Corresponding to this anomaly was an unusual geometry of the iron-bound CO, which was determined by IR and NMR spectroscopies. The effects of camphor and camphor analogues as substrates on the CO-binding kinetics for P-450cam were also studied under pressure. The positive activation volumes for CO binding were obtained for substrate-free and norcamphor- and adamantane-bound P-450, whereas other substrate analogue-bound P-450 complexes exhibited the negative activation volumes. All of the present high-pressure results are discussed in relation to (1) the dynamic aspects of the protein conformation, and (2) the specific participation of amino acid residues in the heme distal site in each elementary step of the ligand-binding reaction process.
Actas de conferencias sobre el tema "Detailed kinetics model"
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LUTZ, ANDREW, ROBERT KEE, ROBERT DIBBLE y JAMES BROADWELL. "A model for detailed chemical kinetics in turbulent nonpremixed jet flames". En 29th Aerospace Sciences Meeting. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1991. http://dx.doi.org/10.2514/6.1991-478.
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Sherrill, Manolo E., Roberto C. Mancini, James E. Bailey, Alex B. Filuk, Brian F. Clark, Patrick Lake y Joseph Abdallah, Jr. "Detailed atomic kinetics model for the spectroscopic analysis of laser-ablated plasma plumes". En Photonics West 2001 - LASE, editado por Richard F. Haglund, Jr., Joseph Neev y Richard F. Wood. SPIE, 2001. http://dx.doi.org/10.1117/12.428007.
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Naik, Chitralkumar V., Karthik V. Puduppakkam, Abhijit Modak, Cheng Wang y Ellen Meeks. "Validated F-T Fuel Surrogate Model for Simulation of Jet-Engine Combustion". En ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23709.
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Validated surrogate models have been developed for two Fisher-Tropsch (F-T) fuels. The models started with a systematic approach to determine an appropriate surrogate fuel composition specifically tailored for the two alternative jet-fuel samples. A detailed chemical kinetic mechanism has been assembled for these model surrogates starting from literature sources, and then improved to ensure self-consistency of the kinetics and thermodynamic data. This mechanism has been tested against fundamental laboratory data on auto-ignition times, laminar flame-speeds, extinction strain rates, and NOx emissions. Literature data used to validate the mechanism include both the individual surrogate-fuel components and actual F-T fuel samples where available. As part of the validation, simulations were performed for a wide variety of experimental configurations, as well as a wide range of temperatures and equivalence ratios for fuel/air mixtures. Comparison of predicted surrogate-fuel behavior against data on real F-T fuel behavior also show the effectiveness of the surrogate-matching approach and the accuracy of the detailed-kinetics mechanisms. The resulting validated mechanism has been also reduced through application of automated mechanism reduction techniques to provide progressively smaller mechanisms, with different degrees of accuracy, that are reasonable for use in CFD simulations employing detailed kinetics.
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Aceves, Salvador M., Joel Martinez-Frias, Daniel L. Flowers, J. Ray Smith, Robert W. Dibble, John F. Wright y Randy P. Hessel. "A Decoupled Model of Detailed Fluid Mechanics Followed by Detailed Chemical Kinetics for Prediction of Iso-Octane HCCI Combustion". En SAE International Fall Fuels & Lubricants Meeting & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2001. http://dx.doi.org/10.4271/2001-01-3612.
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Romano, Augusto y Leonel R. Cancino. "A simplified model for compression-ignition internal combustion engines analysis by using detailed chemical kinetics". En 18th Brazilian Congress of Thermal Sciences and Engineering. ABCM, 2020. http://dx.doi.org/10.26678/abcm.encit2020.cit20-0069.
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Khairallah, H. A. y U. O. Koylu. "Combustion Simulation of Hydrogen-Fuelled Diesel Engines Using Detailed Chemical Kinetics". En ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-65194.
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During the past decade, considerable effort has been made to introduce alternative energy sources for use in conventional diesel and gasoline engines. Many researchers have attempted to use hydrogen as a fuel in the diesel engine due to its ability to reduce pollutant emissions, such as carbon monoxide and unburned hydrocarbons. With the rapid increase in computational capabilities, 3D computational fluid dynamics CFD codes become essential tools for practical design, control and optimization of hydrogen engines. In the present study, detailed chemical kinetic reactions with twenty steps of hydrogen oxidation with additional nitrogen oxidation reactions were coupled with AVL FIRE® code to study combustion processes in a diesel engine using hydrogen as the fuel. Moreover, a spark ignition model built by C++ program was incorporated into the AVL FIRE® software to simulate the hydrogen ignition behavior. The model was validated by the experimental results and employed to examine important parameters that have significant effects on the engine performance. The simulation results show that the variations of peak in-cylinder pressure, heat release rate, gas cylinder temperature, ignition delay, combustion duration, and NO emissions reasonably agree with the experimental findings. The exhaust gas recirculation (EGR) was also employed at different levels in the engine model. It was found that both peak cylinder pressure and gas cylinder temperature decrease as EGR level increases due to dilution effect. The computations are consistent with the hypothesis that gas cylinder temperature decreases with increasing EGR level and that the decrease in gas cylinder temperature results in the reduction in NO emissions.
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Eldeeb, Mazen A. y Malshana Wadugurunnehalage. "Chemical Kinetic Model Reduction and Analysis of Tetrahydrofuran Combustion Using Stochastic Species Elimination". En ASME 2020 Power Conference collocated with the 2020 International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/power2020-16583.
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Abstract In this work, a chemical kinetic modeling study of the high-temperature ignition and laminar flame behavior of Tetrahydrofuran (THF), a promising second-generation transportation biofuel, is presented. Stochastic Species Elimination (SSE) model reduction approach (Eldeeb and Akih-Kumgeh, Proceedings of ASME Power Conference 2018) is implemented to develop multiple skeletal versions of a detailed chemical kinetic model of THF (Fenard et al., Combustion and Flame, 2018) based on ignition delay time simulations at various pressures and temperature ranges. The detailed THF model contains 467 species and 2390 reactions. The developed skeletal versions are combined into an overall reduced model of THF, consisting of 193 species and 1151 reactions. Ignition delay time simulations are performed using detailed and reduced models, with varying levels of agreement observed at most conditions. Sensitivity analysis is then performed to identify the most important reactions responsible for the observed performance of the reduced model. Reaction rate parameter modification is performed for such reactions in order to improve the agreement of detailed and reduced model predictions with literature experimental ignition data. The work contributes toward improved understanding and modeling of the oxidation kinetics of potential transportation biofuels, especially cyclic ethers.
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Liang, Long, Rolf D. Reitz, Claudia O. Iyer y Jianwen Yi. "Modeling Knock in Spark-Ignition Engines Using a G-equation Combustion Model Incorporating Detailed Chemical Kinetics". En SAE World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2007. http://dx.doi.org/10.4271/2007-01-0165.
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Nicolas, Ghassan, Fariba Seiyedzadeh Khanshan, Hameed Metghalchi y Richard H. West. "Reduction Techniques Methods for Simplifying Complex Kinetic Systems: A General Review". En ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36351.
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The development of kinetic models to describe the time evolution of chemically reacting systems is a fundamental objective of chemical kinetics. Ideally, the most accurate approach to this problem is to include all possible species and reactions of any importance to predict, within the specified uncertainty, a wide variety of experimental data. The complexity of these detailed models grows with an increase in the number of fuel components. When the detailed kinetic model is to be coupled to transport equations, the computational tasks often become formidable due to the intrinsic presence of a wide range of time and length scales, which result in the well-known stiffness problem. Such difficulties have motivated the development of numerous model order reduction techniques during the past three decades. In this paper, the most used reduction techniques for detailed kinetic models are presented and the advantages and disadvantages of each are explained.
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Bolin, Christopher D. y Abraham Engeda. "Modeling Static Instabilities of Biogas Flames in a Stirred-Reactor Using Detailed Chemical Kinetics Simulations". En ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95095.
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Kinetic modeling of lean static stability limits of the combustion of biogas type fuels in a model of an ideal primary zone of a gas turbine combustor is presented here. In this study, CH4 is diluted with CO2 to simulate a range of gases representative of the products of anaerobic digestion of organic materials from different sources (e.g., landfill and animal waste digester). Fuels of this type are of interest for use in small gas turbines used in distributed generation applications. Predictions made by two detailed mechanisms (GRI-Mech 3.0 and San Diego) and one reduced mechanism (GRI-Mech 1.2, reduced) are employed to investigate the underlying kinetics near lean extinction. Approximate correlations to lean extinction are extracted from these results and compared to those of other fuels.
Informes sobre el tema "Detailed kinetics model"
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Kao, C. Y. J., S. Elliott, R. P. Turco y X. Zhao. Integrating chemistry into 3D climate models: Detailed kinetics in the troposphere and stratosphere of a global climate model. Office of Scientific and Technical Information (OSTI), noviembre de 1997. http://dx.doi.org/10.2172/548668.
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Kokjohn, Sage. Development and Validation of a Lagrangian Soot Model Considering Detailed Gas Phase Kinetics and Surface Chemistry. Office of Scientific and Technical Information (OSTI), diciembre de 2019. http://dx.doi.org/10.2172/1580657.
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Musculus, Mark P. July 2018 Progress Report for Sandia National Laboratories on DE-EE0007300 Development and Validation of a Lagrangian Soot Model Considering Detailed Gas Phase Kinetics and Surface Chemistry. Office of Scientific and Technical Information (OSTI), julio de 2018. http://dx.doi.org/10.2172/1463071.
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Marinov, N. Detailed chemical kinetic model for ethanol oxidation. Office of Scientific and Technical Information (OSTI), abril de 1997. http://dx.doi.org/10.2172/611758.
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Hart, Carl y Gregory Lyons. A tutorial on the rapid distortion theory model for unidirectional, plane shearing of homogeneous turbulence. Engineer Research and Development Center (U.S.), julio de 2022. http://dx.doi.org/10.21079/11681/44766.
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The theory of near-surface atmospheric wind noise is largely predicated on assuming turbulence is homogeneous and isotropic. For high turbulent wavenumbers, this is a fairly reasonable approximation, though it can introduce non-negligible errors in shear flows. Recent near-surface measurements of atmospheric turbulence suggest that anisotropic turbulence can be adequately modeled by rapid-distortion theory (RDT), which can serve as a natural extension of wind noise theory. Here, a solution for the RDT equations of unidirectional plane shearing of homogeneous turbulence is reproduced. It is assumed that the time-varying velocity spectral tensor can be made stationary by substituting an eddy-lifetime parameter in place of time. General and particular RDT evolution equations for stochastic increments are derived in detail. Analytical solutions for the RDT evolution equation, with and without an effective eddy viscosity, are given. An alternative expression for the eddy-lifetime parameter is shown. The turbulence kinetic energy budget is examined for RDT. Predictions by RDT are shown for velocity (co)variances, one-dimensional streamwise spectra, length scales, and the second invariant of the anisotropy tensor of the moments of velocity. The RDT prediction of the second invariant for the velocity anisotropy tensor is shown to agree better with direct numerical simulations than previously reported.
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Jury, William A. y David Russo. Characterization of Field-Scale Solute Transport in Spatially Variable Unsaturated Field Soils. United States Department of Agriculture, enero de 1994. http://dx.doi.org/10.32747/1994.7568772.bard.
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This report describes activity conducted in several lines of research associated with field-scale water and solute processes. A major effort was put forth developing a stochastic continuum analysis for an important class of problems involving flow of reactive and non reactive chemicals under steady unsaturated flow. The field-scale velocity covariance tensor has been derived from local soil properties and their variability, producing a large-scale description of the medium that embodies all of the local variability in a statistical sense. Special cases of anisotropic medium properties not aligned along the flow direction of spatially variable solute sorption were analysed in detail, revealing a dependence of solute spreading on subtle features of the variability of the medium, such as cross-correlations between sorption and conductivity. A novel method was developed and tested for measuring hydraulic conductivity at the scale of observation through the interpretation of a solute transport outflow curve as a stochastic-convective process. This undertaking provided a host of new K(q) relationships for existing solute experiments and also laid the foundation for future work developing a self-consistent description of flow and transport under these conditions. Numerical codes were developed for calculating K(q) functions for a variety of solute pulse outflow shapes, including lognormal, Fickian, Mobile-Immobile water, and bimodal. Testing of this new approach against conventional methodology was mixed, and agreed most closely when the assumptions of the new method were met. We conclude that this procedure offers a valuable alternative to conventional methods of measuring K(q), particularly when the application of the method is at a scale (e.g. and agricultural field) that is large compared to the common scale at which conventional K(q) devices operate. The same problem was approached from a numerical perspective, by studying the feasibility of inverting a solute outflow signal to yield the hydraulic parameters of the medium that housed the experiment. We found that the inverse problem was solvable under certain conditions, depending on the amount of noise in the signal and the degree of heterogeneity in the medium. A realistic three dimensional model of transient water and solute movement in a heterogeneous medium that contains plant roots was developed and tested. The approach taken was to generate a single realization of this complex flow event, and examine the results to see whether features were present that might be overlooked in less sophisticated model efforts. One such feature revealed is transverse dispersion, which is a critically important component in the development of macrodispersion in the longitudinal direction. The lateral mixing that was observed greatly exceeded that predicted from simpler approaches, suggesting that at least part of the important physics of the mixing process is embedded in the complexity of three dimensional flow. Another important finding was the observation that variability can produce a pseudo-kinetic behavior for solute adsorption, even when the local models used are equilibrium.
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Sessa, Guido y Gregory Martin. A functional genomics approach to dissect resistance of tomato to bacterial spot disease. United States Department of Agriculture, enero de 2004. http://dx.doi.org/10.32747/2004.7695876.bard.
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The research problem. Bacterial spot disease in tomato is of great economic importance worldwide and it is particularly severe in warm and moist areas affecting yield and quality of tomato fruits. Causal agent of spot disease is the Gram-negative bacterium Xanthomonas campestris pv. vesicatoria (Xcv), which can be a contaminant on tomato seeds, or survive in plant debris and in association with certain weeds. Despite the economic significance of spot disease, plant protection against Xcvby cultural practices and chemical control have so far proven unsuccessful. In addition, breeding for resistance to bacterial spot in tomato has been undermined by the genetic complexity of the available sources of resistance and by the multiple races of the pathogen. Genetic resistance to specific Xcvraces have been identified in tomato lines that develop a hypersensitive response and additional defense responses upon bacterial challenge. Central goals of this research were: 1. To identify plant genes involved in signaling and defense responses that result in the onset of resistance. 2. To characterize molecular properties and mode of action of bacterial proteins, which function as avirulence or virulence factors during the interaction between Xcvand resistant or susceptible tomato plants, respectively. Our main achievements during this research program are in three major areas: 1. Identification of differentially expressed genes during the resistance response of tomato to Xcvrace T3. A combination of suppression subtractive hybridization and microarray analysis identified a large set of tomato genes that are induced or repressed during the response of resistant plants to avirulent XcvT3 bacteria. These genes were grouped in clusters based on coordinate expression kinetics, and classified into over 20 functional classes. Among them we identified genes that are directly modulated by expression of the type III effector protein AvrXv3 and genes that are induced also during the tomato resistance response to Pseudomonas syringae pv. tomato. 2. Characterization of molecular and biochemical properties of the tomato LeMPK3MAP kinase. A detailed molecular and biochemical analysis was performed for LeMPK3 MAP kinase, which was among the genes induced by XcvT3 in resistant tomato plants. LeMPK3 was induced at the mRNA level by different pathogens, elicitors, and wounding, but not by defense-related plant hormones. Moreover, an induction of LeMPK3 kinase activity was observed in resistant tomato plants upon Xcvinfection. LeMPK3 was biochemically defined as a dual-specificity MAP kinase, and extensively characterized in vitro in terms of kinase activity, sites and mechanism of autophosphorylation, divalent cation preference, Kₘand Vₘₐₓ values for ATP. 3. Characteriztion of molecular properties of the Xcveffector protein AvrRxv. The avirulence gene avrRxvis involved in the genetic interaction that determines tomato resistance to Xcvrace T1. We found that AvrRxv functions inside the plant cell, localizes to the cytoplasm, and is sufficient to confer avirulence to virulent Xcvstrains. In addition, we showed that the AvrRxv cysteine protease catalytic core is essential for host recognition. Finally, insights into cellular processes activated by AvrRxv expression in resistant plants were obtained by microarray analysis of 8,600 tomato genes. Scientific and agricultural significance: The findings of these activities depict a comprehensive and detailed picture of cellular processes taking place during the onset of tomato resistance to Xcv. In this research, a large pool of genes, which may be involved in the control and execution of plant defense responses, was identified and the stage is set for the dissection of signaling pathways specifically triggered by Xcv.