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You searched for subject:(kinetic relaxation model). Showing records 1 – 2 of 2 total matches.

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Indian Institute of Science

1. Ruhi, Ankit. Kinetic Theory Based Numerical Schemes for Incompressible Flows.

Degree: PhD, Faculty of Science, 2018, Indian Institute of Science

Turbulence is an open and challenging problem for mathematical approaches, physical modeling and numerical simulations. Numerical solutions contribute significantly to the understand of the nature and effects of turbulence. The focus of this thesis is the development of appropriate numerical methods for the computer simulation of turbulent flows. Many of the existing approaches to turbulence utilize analogies from kinetic theory. Degond & Lemou (J. Math. Fluid Mech., 4, 257-284, 2002) derived a k-✏ type turbulence model completely from kinetic theoretic framework. In the first part of this thesis, a numerical method is developed for the computer simulation based on this model. The Boltzmann equation used in the model has an isotropic, relaxation collision operator. The relaxation time in the collision operator depends on the microscopic turbulent energy, making it difficult to construct an efficient numerical scheme. In order to achieve the desired numerical efficiency, an appropriate change of frame is applied. This introduces a stiff relaxation source term in the equations and the concept of asymptotic preserving schemes is then applied to tackle the stiffness. Some simple numerical tests are introduced to validate the new scheme. In the second part of this thesis, alternative approaches are sought for more efficient numerical techniques. The Lattice Boltzmann Relaxation Scheme (LBRS) is a novel method developed recently by Rohan Deshmukh and S.V. Raghuram Rao for simulating compressible flows. Two different approaches for the construction of implicit sub grid scale -like models as Implicit Large Eddy Simulation (ILES) methods, based on LBRS, are proposed and are tested for Burgers turbulence, or Burgulence. The test cases are solved over a largely varying Reynolds number, demonstrating the efficiency of this new ILES-LBRS approach. In the third part of the thesis, as an approach towards the extension of ILES-LBRS to incompressible flows, an artificial compressibility model of LBRS is proposed. The modified framework, LBRS-ACM is then tested for standard viscous incompressible flow test cases. Advisors/Committee Members: Raghurama Rao, S V (advisor), Sekhar, M (advisor).

Subjects/Keywords: Turbulence Modeling; Incompressible Flows; Large Eddy Simulation (LES); Numerical Schemes; Turbulence Model; Lattice Boltzmann Relaxation Scheme (LBRS); Burgers Turbulence; Implicit Large Eddy Simulation (ILES); Turbulence Kinetic Theory; Turbulence; Mathematics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ruhi, A. (2018). Kinetic Theory Based Numerical Schemes for Incompressible Flows. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/3072

Chicago Manual of Style (16th Edition):

Ruhi, Ankit. “Kinetic Theory Based Numerical Schemes for Incompressible Flows.” 2018. Doctoral Dissertation, Indian Institute of Science. Accessed March 07, 2021. http://etd.iisc.ac.in/handle/2005/3072.

MLA Handbook (7th Edition):

Ruhi, Ankit. “Kinetic Theory Based Numerical Schemes for Incompressible Flows.” 2018. Web. 07 Mar 2021.

Vancouver:

Ruhi A. Kinetic Theory Based Numerical Schemes for Incompressible Flows. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2018. [cited 2021 Mar 07]. Available from: http://etd.iisc.ac.in/handle/2005/3072.

Council of Science Editors:

Ruhi A. Kinetic Theory Based Numerical Schemes for Incompressible Flows. [Doctoral Dissertation]. Indian Institute of Science; 2018. Available from: http://etd.iisc.ac.in/handle/2005/3072

2. Saracini, Claudio. CARBON MONOXIDE AND DIOXYGEN PHOTO-RELEASE, BINDING KINETICS, AND THERMODYNAMICS IN 1:1 MONONUCLEAR AND 2:1 DINUCLEAR COPPER/DIOXYGEN COMPLEXES.

Degree: 2014, Johns Hopkins University

Enzymes where the active site contains one or more copper ions catalyze a wide range of organic substrate transformations in Nature. The structures and function of such active sites have been finely tuned by evolution to reach the point where dioxygen binding, activation, and utilization for oxidative chemistry has become finely modulated. As is overviewed in Chapter 1, it is useful to categorize the enzymes supported by two copper centers in their active sites as 'uncoupled' (i.e. in peptidylglycine -hydroxylating monooxygenase (PHM) and in dopamine -monooxygenase (DM)) or 'coupled' (i.e. in tyrosinase (Tyr) and in catechol oxidase (Co)) on the basis of the spatial proximity of the two metals in the three-dimensional matrix of the protein. This proximity has profound effects on the chemistry displayed by these two classes of enzymes. Importantly, dioxygen binding to the copper centers is the first step of the catalytic cycle in all of these systems. However, both mononuclear 1:1 and dinuclear 2:1 copper/O2 adducts forming in the enzymes have been shown to be unstable and their detection and their study has been difficult. As it is also discussed in Chapter 1, low temperature spectroscopic techniques together with synthetic model chemistry have come into play and greatly improved our understanding of the mechanistic details involved in such kinds of reactivity. In this work, laser flash-photolysis techniques in combination with copper-synthetic model chemistry have been employed to help the elucidation of fundamental physical and chemical properties of copper/O2 coordination and dynamics. One of the methods that has been successfully employed to study labile copper/dioxygen adducts is laser flash-photolysis of synthetic (L)copper(I)-CO compounds (L =ligand) in the presence of O2 in organic solvents. In Chapter 2, a flash-photolysis study of tridentate N-donor ligand-copper(I)-CO complexes is presented using such techniques. The implications of tricoordination vs. tetracoordination of copper ion on the dynamics of CO and O2 binding to the metal are discussed for these metal complexes. Tricoordinate environments are more similar in their coordination sphere with those present in the enzymes, as compared to their tetracoordinated synthetic counterparts. In Chapter 3, a new method to study copper/dioxygen binding for mononuclear copper complexes is presented. The previously employed carbon monoxide utilization to start from stable (L)copper(I)-CO complexes is bypassed, in this work, by affording direct O2 photo-release from relatively stable mononuclear copper(II)-superoxide complexes. Interestingly, a different quantum yield for O2 release was found depending on the excitation wavelength used and in collaborative efforts, this effect has been investigated by means of Time-Dependent Density Functional Theory (TD-DFT) studies. This work was further extended and presented in Chapter 4, where the same technique was employed for dinuclear 2:1 Cu/O2 synthetic adducts with a peroxo fragment bound in a side-on mode to the… Advisors/Committee Members: Karlin, Kenneth D (advisor).

Subjects/Keywords: Oxygen activation; coupled copper enzymes; uncoupled copper enzymes; mononuclear and dinuclear copper?O2 adducts; copper synthetic model chemistry; laser flash-photolysis; physical properties; transient absorption spectroscopy; carbon monoxide; dioxygen; tricoordinate; tetracoordinate; flash-and-trap method; copper(II)-superoxide; dicopper(II) peroxo; quantum yield; excitation wavelength; TD-DFT; end-on; side-on; irradiation; visible light; one-photon two-electron; oxidation; hydrogen atom abstraction; reversible; thermodynamics; kinetics; kinetic relaxation model; pseudo-first-order; second-order; rate constant; binding dynamics; tyrosinase; hemocyanin; catechol oxidase; PHM; DBM; irradiation; laser.

…95 2.6 Model Used for Kinetic Studies… …Possible O2 reactive species. 79 xv Scheme 4. Flash-and-trap kinetic model. 81 Chart 1… …Copper-Containing Proteins and in Model Compounds Page Number Figure 1. X-ray crystal structure… …Comparison of kinetic and thermodynamic parameters for O2 binding and dissociation for [(… …applied laser energy for 2. 136 Figure 7. Representative kinetic traces observed at 365 nm… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Saracini, C. (2014). CARBON MONOXIDE AND DIOXYGEN PHOTO-RELEASE, BINDING KINETICS, AND THERMODYNAMICS IN 1:1 MONONUCLEAR AND 2:1 DINUCLEAR COPPER/DIOXYGEN COMPLEXES. (Thesis). Johns Hopkins University. Retrieved from http://jhir.library.jhu.edu/handle/1774.2/37054

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Saracini, Claudio. “CARBON MONOXIDE AND DIOXYGEN PHOTO-RELEASE, BINDING KINETICS, AND THERMODYNAMICS IN 1:1 MONONUCLEAR AND 2:1 DINUCLEAR COPPER/DIOXYGEN COMPLEXES.” 2014. Thesis, Johns Hopkins University. Accessed March 07, 2021. http://jhir.library.jhu.edu/handle/1774.2/37054.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Saracini, Claudio. “CARBON MONOXIDE AND DIOXYGEN PHOTO-RELEASE, BINDING KINETICS, AND THERMODYNAMICS IN 1:1 MONONUCLEAR AND 2:1 DINUCLEAR COPPER/DIOXYGEN COMPLEXES.” 2014. Web. 07 Mar 2021.

Vancouver:

Saracini C. CARBON MONOXIDE AND DIOXYGEN PHOTO-RELEASE, BINDING KINETICS, AND THERMODYNAMICS IN 1:1 MONONUCLEAR AND 2:1 DINUCLEAR COPPER/DIOXYGEN COMPLEXES. [Internet] [Thesis]. Johns Hopkins University; 2014. [cited 2021 Mar 07]. Available from: http://jhir.library.jhu.edu/handle/1774.2/37054.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Saracini C. CARBON MONOXIDE AND DIOXYGEN PHOTO-RELEASE, BINDING KINETICS, AND THERMODYNAMICS IN 1:1 MONONUCLEAR AND 2:1 DINUCLEAR COPPER/DIOXYGEN COMPLEXES. [Thesis]. Johns Hopkins University; 2014. Available from: http://jhir.library.jhu.edu/handle/1774.2/37054

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.