subject:(nonlinearity effect)

Brunel University

1. Khaled, Alhaifi. Numerical and experimental studies of a nonlinear vibration system.

Degree: PhD, 2015, Brunel University

URL: http://bura.brunel.ac.uk/handle/2438/10545 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646261

► The objective of this research is to show that nonlinearity can be used to improve vibration absorption and suppression of unwanted vibrations in a main… (more)

▼ The objective of this research is to show that nonlinearity can be used to improve vibration absorption and suppression of unwanted vibrations in a main system due to external excitation. This was shown by investigating two systems a SDOF (with hardening nonlinearity) and a 2DOF (with softening nonlinearity). The aim of carrying out these investigations was to introduce a passive nonlinear system that can update itself and self-regulate to suppress undesired oscillations. To fulfil the desired gaol, various types of springs were considered and investigated. A commercially available spring called Mag-spring has been chosen and a function for its nonlinearity has been investigated. Mag-Spring is a newly invented spring which is designed to exhibit constant force at its operating range. However, this spring has a special non-linear behaviour before reaching to the constant force domain which is the main focus of the investigation presented in this thesis. The nonlinear behaviour of Mag-spring encouraged the idea that vibration design is possible by the advantages that can be gained from magnetic technology. The added benefit through this new Mag-spring, is that it solved some of the concerns assotiated with old available ones. The most concern norrowing the usage of magnetic springs, is the air gap between the two magnets, which make the attraction or repulsive force unstable through the spring’s working range. Linmot Company, introduced a solution to this concern by introducing a teflone that works as a bearing between the two magnets, which fixed the distance between them while they are sliding againest each other. In the first scenario of this study, a hardening nonlinear spring was added in parallel to a system with a single degree of freedom. The system will remain single degree of freedom as the spring was added in parallel without additional mass. The hardening spring shows low stiffness at low amplitude and high stiffness at higher amplitude. In this study, it was shown that nonlinearity affects the dynamic performance of a system and makes the natural frequency amplitude dependant. As the amplitude of vibration increases, consequently, stiffness increases and the natural frequency shifts away from the excitation frequency. For this investigation, a vibrating system with one degree of freedom has been built based on a mathematical model simulated and tested in Matlab software. Mag-spring was used to introduce the nonlinear stiffness to the system. Unbalance mass mounted to a disc fixed to a rotational machine has been used to create a forced vibration system with variable frequency. The response of the system with and without nonlinearity effect was monitored with an accelerometer. Simulation and experimental results showed that nonlinearity could shift the resonance frequency of the SDOF system by 10% (hardening of the system), without affecting the stiffness of the system at normal working condition. In the second scenario, a softening nonlinear spring was added as a vibration absorber to a system with a…

Subjects/Keywords: Stiffness tuning; nonlinearity effect; Vibration designing; Oscillation elimination validation; Nonlinearity in the means of stiffness

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APA (6^th Edition):

Khaled, A. (2015). Numerical and experimental studies of a nonlinear vibration system. (Doctoral Dissertation). Brunel University. Retrieved from http://bura.brunel.ac.uk/handle/2438/10545 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646261

Chicago Manual of Style (16^th Edition):

Khaled, Alhaifi. “Numerical and experimental studies of a nonlinear vibration system.” 2015. Doctoral Dissertation, Brunel University. Accessed July 23, 2018. http://bura.brunel.ac.uk/handle/2438/10545 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646261.

MLA Handbook (7^th Edition):

Khaled, Alhaifi. “Numerical and experimental studies of a nonlinear vibration system.” 2015. Web. 23 Jul 2018.

Vancouver:

Khaled A. Numerical and experimental studies of a nonlinear vibration system. [Internet] [Doctoral dissertation]. Brunel University; 2015. [cited 2018 Jul 23]. Available from: http://bura.brunel.ac.uk/handle/2438/10545 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646261.

Council of Science Editors:

Khaled A. Numerical and experimental studies of a nonlinear vibration system. [Doctoral Dissertation]. Brunel University; 2015. Available from: http://bura.brunel.ac.uk/handle/2438/10545 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646261

University of Rochester

2. Dolgaleva, Ksenia (1977 - ). Local-field effects and nanostructuring for controlling optical properties and enabling novel optical phenomena.

Degree: PhD, 2009, University of Rochester

URL: http://hdl.handle.net/1802/7147

► My Ph.D. thesis is devoted to the investigation of the methods for controlling and improving the linear and nonlinear optical properties of materials. Within my… (more)

▼ My Ph.D. thesis is devoted to the investigation of the methods for controlling and improving the linear and nonlinear optical properties of materials. Within my studies, two approaches are considered: nanostructuring and invoking local-field effects. These broad topics involve various projects that I have undertaken during my Ph.D. research. The first project is on composite laser gain media. It involves both nanostructuring and using local-field effects to control the basic laser parameters, such as the radiative lifetime, small-signal gain and absorption, and the saturation intensity. While being involved in this project, I have performed both theoretical and experimental studies of laser characteristics of composite materials. In particular, I have developed simple theoretical models for calculating the effective linear susceptibilities of layered and Maxwell Garnett composite materials with a gain resonance in one of their components. The analysis of the results given by the models suggests that local-field effects provide considerable freedom in controlling the optical properties of composite laser gain media. I have also experimentally measured the radiative lifetime of Nd:YAG nanopowder suspended in different liquids to extract information regarding local-field effects. The second project is devoted to the investigation of a not-well-known phenomenon that local-field effects can induce, which is microscopic cascading in nonlinear optics. My Ph.D. thesis is devoted to the investigation of the methods for controlling and improving the linear and nonlinear optical properties of materials. Within my studies, two approaches are considered: nanostructuring and invoking local-field effects. These broad topics involve various projects that I have undertaken during my Ph.D. research. The first project is on composite laser gain media. It involves both nanostructuring and using local-field effects to control the basic laser parameters, such as the radiative lifetime, small-signal gain and absorption, and the saturation intensity. While being involved in this project, I have performed both theoretical and experimental studies of laser characteristics of composite materials. In particular, I have developed simple theoretical models for calculating the effective linear susceptibilities of layered and Maxwell Garnett composite materials with a gain resonance in one of their components. The analysis of the results given by the models suggests that local-field effects provide considerable freedom in controlling the optical properties of composite laser gain media. I have also experimentally measured the radiative lifetime of Nd:YAG nanopowder suspended in different liquids to extract information regarding local-field effects. The second project is devoted to the investigation of a not-well-known phenomenon that local-field effects can induce, which is microscopic cascading in nonlinear optics. This project involves the theoretical prediction of local-field-induced microscopic cascading effect in the fifth-order nonlinear…

Subjects/Keywords: Optical materials; Nanostructuring; Local-field effect; Cascaded nonlinearity; Laser gain media; Optical properties

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APA (6^th Edition):

Dolgaleva, K. (. -. ). (2009). Local-field effects and nanostructuring for controlling optical properties and enabling novel optical phenomena. (Doctoral Dissertation). University of Rochester. Retrieved from http://hdl.handle.net/1802/7147

Chicago Manual of Style (16^th Edition):

Dolgaleva, Ksenia (1977 - ). “Local-field effects and nanostructuring for controlling optical properties and enabling novel optical phenomena.” 2009. Doctoral Dissertation, University of Rochester. Accessed July 23, 2018. http://hdl.handle.net/1802/7147.

MLA Handbook (7^th Edition):

Dolgaleva, Ksenia (1977 - ). “Local-field effects and nanostructuring for controlling optical properties and enabling novel optical phenomena.” 2009. Web. 23 Jul 2018.

Vancouver:

Dolgaleva K(-). Local-field effects and nanostructuring for controlling optical properties and enabling novel optical phenomena. [Internet] [Doctoral dissertation]. University of Rochester; 2009. [cited 2018 Jul 23]. Available from: http://hdl.handle.net/1802/7147.

Council of Science Editors:

Dolgaleva K(-). Local-field effects and nanostructuring for controlling optical properties and enabling novel optical phenomena. [Doctoral Dissertation]. University of Rochester; 2009. Available from: http://hdl.handle.net/1802/7147

University of Toronto

3. Wagner, Sean. Wavelength Conversion in Domain-disordered Quasi-phase Matching Superlattice Waveguides.

Degree: 2011, University of Toronto

URL: http://hdl.handle.net/1807/29903

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This thesis examines second-order optical nonlinear wave mixing processes in domain-disordered quasi-phase matching waveguides and evaluates their potential use in compact, monolithically integrated wavelength conversion… (more)

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This thesis examines second-order optical nonlinear wave mixing processes in domain-disordered quasi-phase matching waveguides and evaluates their potential use in compact, monolithically integrated wavelength conversion devices. The devices are based on a GaAs/AlGaAs superlattice-core waveguide structure with an improved design over previous generations. Quantum-well intermixing by ion-implantation is used to create the quasi-phase matching gratings in which the nonlinear susceptibility is periodically suppressed. Photoluminescence experiments showed a large band gap energy blue shift around 70 nm after intermixing. Measured two-photon absorption coefficients showed a significant polarization dependence and suppression of up to 80% after intermixing. Similar polarization dependencies and suppression were observed in three-photon absorption and nonlinear refraction. Advanced modeling of second-harmonic generation showed reductions of over 50% in efficiency due to linear losses alone. Self-phase modulation was found to be the dominant parasitic nonlinear effect on the conversion efficiency, with reductions of over 60%. Simulations of group velocity mismatch showed modest reductions in efficiency of less than 10%. Experiments on second-harmonic generation showed improvements in efficiency over previous generations due to low linear loss and improved intermixing. The improvements permitted demonstration of continuous wave second-harmonic generation for the first time in such structures with output power exceeding 1 µW. Also, Type-II phase matching was demonstrated for the first time. Saturation was observed as the power was increased, which, as predicted, was the result of self-phase modulation when using 2 ps pulses. By using 20 ps pulses instead, saturation effects were avoided. Thermo-optically induced bistability was observed in continuous wave experiments. Difference frequency generation was demonstrated with wavelengths from the optical C-band being converted to the L- and U-bands with continuous waves. Conversion for Type-I phase matching was demonstrated over 20 nm with signal and idler wavelengths being separated by over 100 nm. Type-II phase matched conversion was also observed. Using the experimental data for analysis, self-pumped conversion devices were found to require external amplification to reach practical output powers. Threshold pump powers for optical parametric oscillators were calculated to be impractically large. Proposed improvements to the device design are predicted to allow more practical operation of integrated conversion devices based on quasi-phase matching superlattice waveguides.

PhD

Advisors/Committee Members: Aitchison, J. Stewart, Helmy, Amr S., Electrical and Computer Engineering.

Subjects/Keywords: nonlinear optics; second-harmonic generation; difference frequency generation; optical Kerr effect; photonic integrated circuit; semiconductor; second-order optical nonlinearity; quasi-phase matching; parametric conversion; superlattice; 0544; 0752

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

APA (6^th Edition):

Wagner, S. (2011). Wavelength Conversion in Domain-disordered Quasi-phase Matching Superlattice Waveguides. (Doctoral Dissertation). University of Toronto. Retrieved from http://hdl.handle.net/1807/29903

Chicago Manual of Style (16^th Edition):

Wagner, Sean. “Wavelength Conversion in Domain-disordered Quasi-phase Matching Superlattice Waveguides.” 2011. Doctoral Dissertation, University of Toronto. Accessed July 23, 2018. http://hdl.handle.net/1807/29903.

MLA Handbook (7^th Edition):

Wagner, Sean. “Wavelength Conversion in Domain-disordered Quasi-phase Matching Superlattice Waveguides.” 2011. Web. 23 Jul 2018.

Vancouver:

Wagner S. Wavelength Conversion in Domain-disordered Quasi-phase Matching Superlattice Waveguides. [Internet] [Doctoral dissertation]. University of Toronto; 2011. [cited 2018 Jul 23]. Available from: http://hdl.handle.net/1807/29903.

Council of Science Editors:

Wagner S. Wavelength Conversion in Domain-disordered Quasi-phase Matching Superlattice Waveguides. [Doctoral Dissertation]. University of Toronto; 2011. Available from: http://hdl.handle.net/1807/29903

Brno University of Technology

4. Plačko, Michal. Číslicová simulace kytarových hudebních efektů v reálném čase .

Degree: 2011, Brno University of Technology

URL: http://hdl.handle.net/11012/5032

► Cieľom práce je oboznámiť sa so spôsobmi simulácie gitarových hudobných efektov, konkrétne s metódou stavového priestoru so statickou nelinearitou, v prostredí Matlab navrhnúť a odladiť… (more)

Subjects/Keywords: Efekt distortion; Číslicová simulácia; Metóda stavového priestoru so statickou nelinearitou (SSMN); Matlab; Diódový orezávač.; Effect distortion; Digital simulation; State space memoryless nonlinearity (SSMN); Matlab; Diode clipper

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APA (6^th Edition):

Plačko, M. (2011). Číslicová simulace kytarových hudebních efektů v reálném čase . (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/5032

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

Chicago Manual of Style (16^th Edition):

Plačko, Michal. “Číslicová simulace kytarových hudebních efektů v reálném čase .” 2011. Thesis, Brno University of Technology. Accessed July 23, 2018. http://hdl.handle.net/11012/5032.

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

MLA Handbook (7^th Edition):

Plačko, Michal. “Číslicová simulace kytarových hudebních efektů v reálném čase .” 2011. Web. 23 Jul 2018.

Vancouver:

Plačko M. Číslicová simulace kytarových hudebních efektů v reálném čase . [Internet] [Thesis]. Brno University of Technology; 2011. [cited 2018 Jul 23]. Available from: http://hdl.handle.net/11012/5032.

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

Council of Science Editors:

Plačko M. Číslicová simulace kytarových hudebních efektů v reálném čase . [Thesis]. Brno University of Technology; 2011. Available from: http://hdl.handle.net/11012/5032

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

Université Paris-Sud – Paris XI

5. Rolle, Jérémie. Étude de la dynamique plasma dans la filamentation laser induite dans les verres de silice en présence de rétrodiffusion Brillouin stimulée et dans les cristaux de KDP : Study of a dynamical plasma response in laser filamentation induced in silica glasses in presence of stimulated Brillouin scattering and in KDP crystals.

Degree: Docteur es, Physique, 2014, Université Paris-Sud – Paris XI

URL: http://www.theses.fr/2014PA112195

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Dans cette thèse, nous étudions l’influence d’un plasma non-stationnaire produit par des impulsions laser en régime d’auto-focalisation. Cette auto-focalisation est couplée à des non-linéarités Brillouin… (more)

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Dans cette thèse, nous étudions l’influence d’un plasma non-stationnaire produit par des impulsions laser en régime d’auto-focalisation. Cette auto-focalisation est couplée à des non-linéarités Brillouin pour des impulsions nanosecondes dans les verres de silice. Elle excite différents canaux d’ionisation dans les cristaux de KDP irradiées par des impulsions femtosecondes. Tout d’abord, nous dérivons les équations de propagation des ondes optiques laser et Stokes sujettes à la filamentation due à l’effet Kerr, la rétrodiffusion Brillouin et à la génération de plasma. Dans une deuxième partie, nous présentons des résultats numériques sur la propagation non-linéaire de faisceaux LIL. Ceux-ci révèlent l’importance de la distribution temporelle de l’impulsion pompe dans la compétition entre auto-compression Kerr et la rétrodiffusion Brillouin stimulée. Ces simulations préliminaires permettent de valider le système anti-Brillouin opté pour le LMJ sur la base de faisceaux millimétriques.Dans une troisième partie, nous présentons des résultats théoriques et numériques sur la filamentation d’impulsions nanosecondes opérant dans l’ultraviolet et l’infrarouge. L’influence d’un plasma inertiel sur la dynamique de couplage de deux ondes en contre-propagation est examinée. Dans une configuration à une onde, une analyse variationnelle reproduit les caractéristiques globales d’un équilibre quasi-stationnaire entre auto-compression Kerr et défocalisation plasma. Toutefois, cet équilibre cesse pour faire place à des instabilités modulationnelles induites par rétroaction du plasma sur l’onde de pompe. Nous montrons que des modulations de phase supprimant la rétrodiffusion Brillouin permettent d’inhiber ces instabilités plasma. La robustesse de ces modulations de phase est testée en présence d’un bruit aléatoire dans le profil de l’impulsion laser.Enfin, nous étudions numériquement la dynamique non-linéaire d’impulsions femtosecondes se propageant dans la silice et le KDP. Premièrement, nous montrons que la présence de défauts impliquant moins de photons pour exciter un électron de la bande de valence à la bande de conduction promeut des intensités de filamentation plus élevées. Ensuite, nous comparons la dynamique de filamentation dans la silice avec celle dans un cristal KDP. Le modèle d’ionisation pour le KDP prend en compte la présence de défauts et la dynamique électrons-trous. Nous montrons que la dynamique de propagation dans la silice et le KDP présente des analogies remarquables pour des rapports de puissance incidente sur puissance critique équivalents.La conclusion nous permet de résumer les résultats originaux obtenus dans le cadre de cette thèse et d’en discuter des développements ultérieurs possibles.

In this thesis, we study the role of an inertial plasma reponse produced by laser pulses in self-focusing regime. Self-focusing is coupled with Brillouin nonlinearities for nanosecond pulses in silica glasses. For femtosecond pulses propagating in KDP crystals, self-focusing excites various ionization chanels. First of…

Advisors/Committee Members: Bergé, Luc (thesis director).

Subjects/Keywords: Interaction laser-matière; Endommagement laser; Équation de Schrödinger non-linéaire; Effet Kerr; Auto-focalisation; Filamentation; Multifilamentation; Diffusion Brillouin stimulée; Non-linéarité saturante; Ionisation; Silice; KDP; Laser-matter interaction; Laser-induced damage; Nonlinear Schrödinger equation; Kerr effect; Self-focusing; Filamentation; Multifilamentation; Stimulated Brillouin Scattering; Ionisation; Saturated nonlinearity; Silica; KDP

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

APA (6^th Edition):

Rolle, J. (2014). Étude de la dynamique plasma dans la filamentation laser induite dans les verres de silice en présence de rétrodiffusion Brillouin stimulée et dans les cristaux de KDP : Study of a dynamical plasma response in laser filamentation induced in silica glasses in presence of stimulated Brillouin scattering and in KDP crystals. (Doctoral Dissertation). Université Paris-Sud – Paris XI. Retrieved from http://www.theses.fr/2014PA112195

Chicago Manual of Style (16^th Edition):

Rolle, Jérémie. “Étude de la dynamique plasma dans la filamentation laser induite dans les verres de silice en présence de rétrodiffusion Brillouin stimulée et dans les cristaux de KDP : Study of a dynamical plasma response in laser filamentation induced in silica glasses in presence of stimulated Brillouin scattering and in KDP crystals.” 2014. Doctoral Dissertation, Université Paris-Sud – Paris XI. Accessed July 23, 2018. http://www.theses.fr/2014PA112195.

MLA Handbook (7^th Edition):

Rolle, Jérémie. “Étude de la dynamique plasma dans la filamentation laser induite dans les verres de silice en présence de rétrodiffusion Brillouin stimulée et dans les cristaux de KDP : Study of a dynamical plasma response in laser filamentation induced in silica glasses in presence of stimulated Brillouin scattering and in KDP crystals.” 2014. Web. 23 Jul 2018.

Vancouver:

Rolle J. Étude de la dynamique plasma dans la filamentation laser induite dans les verres de silice en présence de rétrodiffusion Brillouin stimulée et dans les cristaux de KDP : Study of a dynamical plasma response in laser filamentation induced in silica glasses in presence of stimulated Brillouin scattering and in KDP crystals. [Internet] [Doctoral dissertation]. Université Paris-Sud – Paris XI; 2014. [cited 2018 Jul 23]. Available from: http://www.theses.fr/2014PA112195.

Council of Science Editors:

Rolle J. Étude de la dynamique plasma dans la filamentation laser induite dans les verres de silice en présence de rétrodiffusion Brillouin stimulée et dans les cristaux de KDP : Study of a dynamical plasma response in laser filamentation induced in silica glasses in presence of stimulated Brillouin scattering and in KDP crystals. [Doctoral Dissertation]. Université Paris-Sud – Paris XI; 2014. Available from: http://www.theses.fr/2014PA112195

Texas A&M University

6. Cho, Yong Hee 1976-. Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors.

Degree: 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/152436

► In this work we apply the methods of band structure calculation combined with self-consistent treatment of the light-matter interaction to a variety of problems in… (more)

▼ In this work we apply the methods of band structure calculation combined with self-consistent treatment of the light-matter interaction to a variety of problems in bulk semiconductors and semiconductor heterostructures as well as in new optoelectronic devices. In particular, we utilize the 30- and 8-band k ? p band structure calculation methods to study the electronic, magnetic, and optical properties of the diluted magnetic semiconductor, GaMnAs, in the mean-field Zener model. We calculate the anisotropic dielectric response of GaMnAs in the metallic regime and show that our model produces a good agreement with the experimental results of magneto-optical Kerr spectroscopy in the interband transition region. We also discuss the advantages of the 30-band k ? p model for spin-polarized ferromagnetic GaMnAs. We present new methods for calculating electronic states in low-dimensional semiconductor heterostructures based on the real-space Hamiltonian. The formalism provides extreme simplicity of the numerical implementation and superior accuracy of the results. They are applicable to a general n-band k ? p model and specifically tested in the 6-, 8-band k ? p models, and a simple parabolic one band model. The transparency of the new method allows us to investigate the origin and elimination of spurious solutions in the unified manner. Spurious solutions have long been a major issue in low- dimensional band structure calculations. As an application of nonlinear optical interactions in two-dimensional semiconductor heterostructures, we calculate the upper limits on the efficiency of the passive terahertz difference frequency generation based on the intersubband resonant nonlinearity. Our approach incorporates electronic states together with propagating coupled fields through the self-consistent calculation of the Poisson equation, density matrix equations, and coupled wave equations. We develop optimal device geometries and systematically study the device performance as a function of various parameters. The results are compared with a simplified analytic solution. Advisors/Committee Members: Belyanin, Alexey (advisor), Eknoyan, Ohannes (committee member), Kocharovskaya, Olga (committee member), Sinova, Jairo (committee member).

Subjects/Keywords: conversion efficiency; Poisson equation; densty matrix equation; coupled field equations in lossy media; difference frequency generation; terahertz(THz) radiation; self-consistent calculation; resonant nonlinearity; intersubband transition; 8-band k ? p model; envelope function approximation; Fourier grid Hamiltonian method; delta function method; eigen solutions in semiconductor quantum wells; semiconductor heterostructure; low dimensional semiconductor; interband transition; Kerr effect; 30-band k ? p model; GaMnAs; Diluted magnetic semiconductor

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APA (6^th Edition):

Cho, Y. H. 1. (2011). Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152436

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

Chicago Manual of Style (16^th Edition):

Cho, Yong Hee 1976-. “Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors.” 2011. Thesis, Texas A&M University. Accessed July 23, 2018. http://hdl.handle.net/1969.1/152436.

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

MLA Handbook (7^th Edition):

Cho, Yong Hee 1976-. “Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors.” 2011. Web. 23 Jul 2018.

Vancouver:

Cho YH1. Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors. [Internet] [Thesis]. Texas A&M University; 2011. [cited 2018 Jul 23]. Available from: http://hdl.handle.net/1969.1/152436.

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

Council of Science Editors:

Cho YH1. Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors. [Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/152436

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

Brigham Young University

7. Critchfield, Brian L. Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst.

Degree: MS, 2006, Brigham Young University

URL: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2044&context=etd

► Fischer-Tropsch Synthesis (FTS) is a promising technology for the production of ultra-clean fuels and chemical feedstocks from biomass, coal, or natural gas. Iron catalysts are… (more)

▼ Fischer-Tropsch Synthesis (FTS) is a promising technology for the production of ultra-clean fuels and chemical feedstocks from biomass, coal, or natural gas. Iron catalysts are ideal for conversion of coal and biomass. However, precipitated iron catalysts used in slurry-bubble column reactors suffer from high attrition resulting in difficulty separating catalysts from product and increased slurry viscosity. Thus, development of an active and selective-supported iron catalyst to manage attrition is needed. This thesis focuses on the development of a supported iron catalyst and kinetic models of FTS on the catalyst using advanced statistical methods for experimental design and analysis. A high surface area alumina, modified by the addition of approximately 2 wt% lanthanum, was impregnated with approximately 20 wt% Fe and 1% Pt in a two step procedure. Approximately 10 wt% Fe and 0.5 wt% Pt was added in each step. The catalyst had a CO uptake of 702 μmol/g, extent of reduction of 69%, and was reduced at 450°C. The catalyst was stable over H2 partial pressures of 4-10 atm, CO partial pressures of 1-4 atm, and temperatures of 220-260°C. Weisz modulus values were less than 0.15. A Langmuir-Hinshelwood type rate expression, derived from a proposed FTS mechanism, was used with D-optimal criterion to develop experiments sequentially at 220°C and 239°C. Joint likelihood confidence regions for the rate expression parameters with respect to run number indicate rapid convergence to precise-parameter estimates. Difficulty controlling the process at the designed conditions and steep gradients around the D-optimal criterion resulted in consecutive runs having the same optimal condition. In these situations another process condition was chosen to avoid consecutive replication of the same process condition. A kinetic model which incorporated temperature effects was also regressed. Likelihood and bootstrap confidence intervals suggested that the model parameters were precise. Histograms and skewness statistics calculated from Bootstrap resampling show parameter-effect nonlinearities were small.

Subjects/Keywords: fischer tropsch synthesis; bootstrap method; d optimal; computer generated experimental designs; kinetic model; statistical experimental design; kinetic model; boottstrap resampling; slurry-bubble column; supported iron catalyst; nonlinear least squares regression; lanthanum modified alumina; langmuir hinshelwood rate expression; likelihood confidence regions; skewness statistic; histogram; mechanism; parameter effect nonlinearity; sequential experimental design; weisz modulus; attrition; optimal design; impregnation; Chemical Engineering

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

APA (6^th Edition):

Critchfield, B. L. (2006). Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst. (Masters Thesis). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2044&context=etd

Chicago Manual of Style (16^th Edition):

Critchfield, Brian L. “Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst.” 2006. Masters Thesis, Brigham Young University. Accessed July 23, 2018. https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2044&context=etd.

MLA Handbook (7^th Edition):

Critchfield, Brian L. “Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst.” 2006. Web. 23 Jul 2018.

Vancouver:

Critchfield BL. Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst. [Internet] [Masters thesis]. Brigham Young University; 2006. [cited 2018 Jul 23]. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2044&context=etd.

Council of Science Editors:

Critchfield BL. Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst. [Masters Thesis]. Brigham Young University; 2006. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2044&context=etd

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