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1.
Martel, Laura.
Etude de la séparation de phase dans des verres silicatés par résonance magnétique nucléaire haute résolution solide et microscopie electronique : Study of phase separation in silicate glasses using high resolution solid state nuclear magnetic resonance and electron microscopy.
Degree: Docteur es, Physique et chimie des matériaux, 2011, Université d'Orléans
URL: http://www.theses.fr/2011ORLE2034 
► La compréhension de la structure des verres est actuellement à l’origine de nombreuses recherches scientifiques. L’une des preuves expérimentale d’un certain ordre dans ceux-ci est…
(more)
▼ La compréhension de la structure des verres est actuellement à l’origine de nombreuses recherches scientifiques. L’une des preuves expérimentale d’un certain ordre dans ceux-ci est la séparation de phase. En effet, ce phénomène est lié à la présence dans ces matériaux amorphes d’au moins deux phases de composition chimique différentes. Ainsi, une étude des prémices de la séparation de phase de type nucléation-croissance dans des verres de silicate de sodium a été menée. La RMN c’est révélée la plus efficace pour cette étude. L’utilisation des expériences de corrélation 29Si-29Si a permis de sonder le réseau silicaté à des échelles plus grandes que celles communément considérées. Nous avons donc pu identifier ce phénomène, caractériser la composition des phases qui apparaissaient et enfin établi un lien avec la cristallisation observée pour de long temps de recuits. A l’inverse, la séparation de phase dans les aluminosilicates de calcium étant visible à l’échelle macroscopique, nous voulions donc suivre la diminution de la séparation de phase avec l’ajout d’alumine. Ainsi, en élaborant un protocole de synthèse spécifique, nous avons pu synthétiser ces verres à hautes températures. Ils ont été étudiés par le biais de la microscopie électronique et de la RMN. Comme ces verres sont composés de nano-domaines vitreux intégrés dans une matrice de composition différente, nous avons pu obtenir des matériaux nano-structurés de taille contrôlée. L’utilisation de la RMN nous a permis de montrer que l’aluminium s’insérait sous forme de « clusters » dans le réseau silicaté.
The understanding of the vitreous state is actually a center of great interest in inorganic chemistry. In fact, even if a glass is often described as a totally disordered material, presence of structures at the atomic scale has to be considered. One of the first experimental proof against the random network theory is the observation of phase separation. In fact, in these systems, at least two glasses with different compositions are observed. In this way, the first steps of phase separation in sodium silicate glasses have been studied. This was afforded with the NMR technique using 29Si-29Si correlations experiments. Thus, the silicon network was probed at higher distances compared with which was commonly observed in these glasses. Therefore, we have been able to identify this phenomenon at the atomic scale, to define the composition of each glassy phase and to do a link with crystallization which happened after long heat treatment of the glass. At the contrary phase separation in calcium aluminosilicate glasses can be observed at the macroscopic scale, observation of its decrease with increasing amount of alumina has been under the scope of this study. The main challenge of this study was to synthesized high temperature glasses. Since an efficient protocol has been implemented, we have been able to obtained nano-structured materials with a controlled size of nano-domains. This caracterisation of the material has been possible using electron microscopy.…
Advisors/Committee Members: Massiot, Dominique (thesis director).
Subjects/Keywords: Séparation de phase; Phase separation
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APA (6th Edition):
Martel, L. (2011). Etude de la séparation de phase dans des verres silicatés par résonance magnétique nucléaire haute résolution solide et microscopie electronique : Study of phase separation in silicate glasses using high resolution solid state nuclear magnetic resonance and electron microscopy. (Doctoral Dissertation). Université d'Orléans. Retrieved from http://www.theses.fr/2011ORLE2034
Chicago Manual of Style (16th Edition):
Martel, Laura. “Etude de la séparation de phase dans des verres silicatés par résonance magnétique nucléaire haute résolution solide et microscopie electronique : Study of phase separation in silicate glasses using high resolution solid state nuclear magnetic resonance and electron microscopy.” 2011. Doctoral Dissertation, Université d'Orléans. Accessed March 04, 2021.
http://www.theses.fr/2011ORLE2034.
MLA Handbook (7th Edition):
Martel, Laura. “Etude de la séparation de phase dans des verres silicatés par résonance magnétique nucléaire haute résolution solide et microscopie electronique : Study of phase separation in silicate glasses using high resolution solid state nuclear magnetic resonance and electron microscopy.” 2011. Web. 04 Mar 2021.
Vancouver:
Martel L. Etude de la séparation de phase dans des verres silicatés par résonance magnétique nucléaire haute résolution solide et microscopie electronique : Study of phase separation in silicate glasses using high resolution solid state nuclear magnetic resonance and electron microscopy. [Internet] [Doctoral dissertation]. Université d'Orléans; 2011. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2011ORLE2034.
Council of Science Editors:
Martel L. Etude de la séparation de phase dans des verres silicatés par résonance magnétique nucléaire haute résolution solide et microscopie electronique : Study of phase separation in silicate glasses using high resolution solid state nuclear magnetic resonance and electron microscopy. [Doctoral Dissertation]. Université d'Orléans; 2011. Available from: http://www.theses.fr/2011ORLE2034
University of Manchester
2.
Ward, Joseph.
MAX phase ceramics for nuclear applications.
Degree: 2018, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314189
► The PhD research presented here is part of the new nuclear manufacturing (NNUMAN) research group, looking into novel materials and manufacturing processes. NNUMAN is an…
(more)
▼ The PhD research presented here is part of the new
nuclear manufacturing (NNUMAN) research group, looking into novel
materials and manufacturing processes. NNUMAN is an EPSRC funded
(EP/J021172/1) program with direct support from Rolls Royce plc.
The fabrication of MAX
phase coatings by different means and
assessing their tribological properties was the original theme of
this thesis. However, due to issues with fabrication processes the
overriding direction was moved towards assessing the response of
bulk MAX phases to irradiating and corrosive environments. It is
believed that this research will contribute to the understanding of
suitable compositions and applications within nuclear. The MAX
phases comprise an early transition metal (M), an A-group element
(A) and either carbon or nitrogen (X). They have an inherently
nano-layered structure with alternating ceramic (MX) and metallic
(A) layers. The unique mix of both ceramic and metallic properties
have made MAX phases a proposed material for nuclear applications.
Proton irradiation is performed on Ti3SiC2, Ti3AlC2, Ti2AlC and
Cr2AlC bulk MAX phases to 0.1 dpa at 350 °C. Crystallographic
instabilities are observed through x-ray diffraction (XRD) analysis
after irradiation. A mechanism for irradiation induced point defect
swelling is proposed, by matching XRD and modelling data. Anti-site
point defects are proposed to be a major contributor to anisotropic
lattice parameter changes in Ti3SiC2. Additional carbon
interstitial defects are also proposed in Ti3AlC2, as well as
anti-site defects, making them less radiation tolerant. Further
proton irradiations on Ti3SiC2 and Ti3AlC2 were performed at
elevated temperatures to propose a temperature at which lattice
changes are not observed. It is concluded that high proton fluences
require temperatures in excess of ~700 °C and ~1,000 °C for Ti3SiC2
and Ti3AlC2, respectively. Corrosion of bulk MAX phases in
simulated primary water also suggests a deleterious response to
normal light water reactor (LWR) operations. Advanced scanning
transmission electron microscopy (STEM) techniques, such as energy
dispersive x-ray spectroscopy (EDS) and electron energy loss
spectroscopy (EELS), is employed to understand corrosion
mechanisms. Selective oxidation of A-layers is observed, with no
evidence of passivation for Ti3SiC2, Ti3AlC2 and Ti2AlC. The
response of Cr2AlC was most promising as little oxidation occurred,
which is confirmed also with XRD analysis. A comprehensive
corrosion mechanism is proposed, whereby compositions of MAX
phase
in LWR coolants is limited.
Advisors/Committee Members: FRANKEL, PHILIPP PG, WITHERS, PHILIP PJ, Preuss, Michael, Frankel, Philipp, Withers, Philip.
Subjects/Keywords: MAX phase
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APA (6th Edition):
Ward, J. (2018). MAX phase ceramics for nuclear applications. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314189
Chicago Manual of Style (16th Edition):
Ward, Joseph. “MAX phase ceramics for nuclear applications.” 2018. Doctoral Dissertation, University of Manchester. Accessed March 04, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314189.
MLA Handbook (7th Edition):
Ward, Joseph. “MAX phase ceramics for nuclear applications.” 2018. Web. 04 Mar 2021.
Vancouver:
Ward J. MAX phase ceramics for nuclear applications. [Internet] [Doctoral dissertation]. University of Manchester; 2018. [cited 2021 Mar 04].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314189.
Council of Science Editors:
Ward J. MAX phase ceramics for nuclear applications. [Doctoral Dissertation]. University of Manchester; 2018. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314189
University of North Texas
3.
Soni, Vishal.
Phase Transformations in Refractory High Entropy Alloys.
Degree: 2019, University of North Texas
URL: https://digital.library.unt.edu/ark:/67531/metadc1538735/
► High entropy alloys (HEAs) based on refractory elements have shown a great potential for high temperature structural applications. In particular, the ones containing Al, exhibits…
(more)
▼ High entropy alloys (HEAs) based on refractory elements have shown a great potential for high temperature structural applications. In particular, the ones containing Al, exhibits a microstructure similar to the γ-γ' in Ni-based superalloys. While these alloys exhibit impressive strengths at room temperature (RT) and at elevated temperatures, the continuous B2 matrix in these alloys is likely to be responsible for their brittle behavior at RT.
Phase stability of five such alloys are studied by thermo-mechanical treatments and characterization techniques using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Two of these alloys showed an inverted microstructure, where the disordered BCC
phase becomes continuous, and therefore, they were characterized in detail using SEM, TEM, atom probe tomography (APT) and synchrotron x-ray diffraction experiments. The phenomenon of
phase inversion lead to a better combination of strength and ductility as compared to the non-inverted microstructure.To enhance the stability of B2 intermetallic
phase which provides the strength when present in a BCC matrix, multicomponent B2
phase compositions stable at 1000°C in some of the above studied alloys, were melted separately. The aim was to establish a single
phase B2 at 1000°C and understand the mechanical behavior of these single-
phase multicomponent B2 intermetallic alloys. These alloys exhibited a ductile behavior under compression and retained ~1 GPa yield strength at temperature up to 600°C. The ductile nature of these alloys is attributed to the change in bonding nature form directional to metallic bonding, possibly resulting from a significantly high configurational entropy compared to binary or ternary stoichiometric B2 compounds.
Advisors/Committee Members: Banerjee, Rajarshi, Srivilliputhur, Srinivasan G., Mishra, Rajiv S., Mukherjee, Sundeep, Scharf, Thomas, Fraser, Hamish.
Subjects/Keywords: phase; microscopy
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4.
Rice, James W.
Thermodynamics and Phase Behavior of Polycyclic Aromatic
Hydrocarbon Mixtures.
Degree: PhD, Fluids, Thermal, and Chemical Processing, 2011, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:11275/
► Polycyclic aromatic hydrocarbons (PAHs) are normally found in mixtures of many similarly structured compounds. The goal of the research presented in this thesis is to…
(more)
▼ Polycyclic aromatic hydrocarbons (PAHs) are normally
found in mixtures of many similarly structured compounds. The goal
of the research presented in this thesis is to better understand
PAH mixture thermodynamics by studying the
phase behavior of PAH
systems. The compounds examined are common PAHs and are also common
components of PAH mixtures, which have considerable environmental
and industrial significance.PAH mixtures have been studied using
differential scanning calorimetry, melting temperature analysis,
X-ray diffraction, and Knudsen effusion (for vapor pressure).
Furthermore, experiments were conducted to better characterize the
aqueous solubility of PAH mixtures and sorption behavior of pure
PAHs to soils.Thermochemical and vapor pressure experiments were
used to examine the
phase behavior of the anthracene + pyrene and
anthracene + benzo[a]pyrene systems. Solid-liquid
phase diagrams
were mapped for the mixtures. Eutectic points occur for both
mixture systems. Models based on eutectic
phase formation can be
used to predict the enthalpies of fusion associated with the
mixtures. Solid-vapor equilibrium, i.e., vapor pressure, studies
show that mixtures of anthracene and pyrene form solid azeotropes
and also suggest that the solid-vapor equilibrium of benzo[a]pyrene
is not significantly influenced by moderate levels of anthracene in
the crystal structure. A transition occurs from the non-ideal solid
mixtures (above) to a relatively ideal liquid behavior
characteristic of "tars". Ternary mixtures of anthracene, pyrene
and fluoranthene show behavior that is consistent with the binary
PAH mixtures; that is, the initially solid mixture exhibits a
significant melting point depression, relative to the pure
components, and in a certain range of composition, solid azeotrope
behavior on vaporization. As the number of distinct PAH species is
increased (by adding in benzo[a]pyrene, phenanthrene, fluorene and
chrysene) this behavior gradually leads to liquid
phase character
even at room temperature, and the vaporization behavior approaches
that crudely predictable from ideal mixture theory.
Advisors/Committee Members: Suuberg, Eric (Director), Calo, Joseph (Reader), Diebold, Gerald (Reader).
Subjects/Keywords: Phase equilibria
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APA (6th Edition):
Rice, J. W. (2011). Thermodynamics and Phase Behavior of Polycyclic Aromatic
Hydrocarbon Mixtures. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:11275/
Chicago Manual of Style (16th Edition):
Rice, James W. “Thermodynamics and Phase Behavior of Polycyclic Aromatic
Hydrocarbon Mixtures.” 2011. Doctoral Dissertation, Brown University. Accessed March 04, 2021.
https://repository.library.brown.edu/studio/item/bdr:11275/.
MLA Handbook (7th Edition):
Rice, James W. “Thermodynamics and Phase Behavior of Polycyclic Aromatic
Hydrocarbon Mixtures.” 2011. Web. 04 Mar 2021.
Vancouver:
Rice JW. Thermodynamics and Phase Behavior of Polycyclic Aromatic
Hydrocarbon Mixtures. [Internet] [Doctoral dissertation]. Brown University; 2011. [cited 2021 Mar 04].
Available from: https://repository.library.brown.edu/studio/item/bdr:11275/.
Council of Science Editors:
Rice JW. Thermodynamics and Phase Behavior of Polycyclic Aromatic
Hydrocarbon Mixtures. [Doctoral Dissertation]. Brown University; 2011. Available from: https://repository.library.brown.edu/studio/item/bdr:11275/
Universidad de Cantabria
5.
Martín Rodríguez, Rosa.
Síntesis, caracterización estructural y estudio espectroscópico de materiales nanocristalinos y microcristalinos: Synthesis, structural characterization and spectroscopic study of nanocrystalline and microcrystalline materials.
Degree: 2011, Universidad de Cantabria
URL: http://hdl.handle.net/10902/1564
► RESUMEN: El trabajo resumido en esta tesis se ha llevado a cabo dentro del grupo de Altas Presiones y Espectroscopia de la Universidad de Cantabria…
(more)
▼ RESUMEN: El trabajo resumido en esta tesis se ha llevado a cabo dentro del grupo de Altas Presiones y Espectroscopia de la Universidad de Cantabria y tiene dos objetivos principales. Por un lado, se han estudiado las propiedades ópticas de distintos iones de metales de transición y tierras raras en diversas redes aislantes. Se han realizado medidas experimentales de luminiscencia, absorción, tiempo de vida y espectroscopia resuelta en tiempo. Concretamente, uno de los objetivos principales ha sido establecer los mecanismos responsables de la luminiscencia de upconversion de los materiales estudiados, y los requerimientos estructurales para aumentar su eficiencia. Para ello se han comparado diversos métodos de síntesis así como diferentes concentraciones de impurezas. Asimismo, se han investigado transiciones de fase a alta presión en semiconductores con tamaño de partícula en el rango de los nanómetros mediante absorción óptica, espectroscopia Raman y difracción de rayos X. La síntesis de las muestras representa también una parte muy importante de este trabajo.
Advisors/Committee Members: Valiente Barroso, Rafael (advisor), Universidad de Cantabria (other).
Subjects/Keywords: Phase transitions
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APA (6th Edition):
Martín Rodríguez, R. (2011). Síntesis, caracterización estructural y estudio espectroscópico de materiales nanocristalinos y microcristalinos: Synthesis, structural characterization and spectroscopic study of nanocrystalline and microcrystalline materials. (Doctoral Dissertation). Universidad de Cantabria. Retrieved from http://hdl.handle.net/10902/1564
Chicago Manual of Style (16th Edition):
Martín Rodríguez, Rosa. “Síntesis, caracterización estructural y estudio espectroscópico de materiales nanocristalinos y microcristalinos: Synthesis, structural characterization and spectroscopic study of nanocrystalline and microcrystalline materials.” 2011. Doctoral Dissertation, Universidad de Cantabria. Accessed March 04, 2021.
http://hdl.handle.net/10902/1564.
MLA Handbook (7th Edition):
Martín Rodríguez, Rosa. “Síntesis, caracterización estructural y estudio espectroscópico de materiales nanocristalinos y microcristalinos: Synthesis, structural characterization and spectroscopic study of nanocrystalline and microcrystalline materials.” 2011. Web. 04 Mar 2021.
Vancouver:
Martín Rodríguez R. Síntesis, caracterización estructural y estudio espectroscópico de materiales nanocristalinos y microcristalinos: Synthesis, structural characterization and spectroscopic study of nanocrystalline and microcrystalline materials. [Internet] [Doctoral dissertation]. Universidad de Cantabria; 2011. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/10902/1564.
Council of Science Editors:
Martín Rodríguez R. Síntesis, caracterización estructural y estudio espectroscópico de materiales nanocristalinos y microcristalinos: Synthesis, structural characterization and spectroscopic study of nanocrystalline and microcrystalline materials. [Doctoral Dissertation]. Universidad de Cantabria; 2011. Available from: http://hdl.handle.net/10902/1564
Universidad de Cantabria
6.
Sánchez de la Lama, Marta.
Fenómenos complejos en sistemas extendidos en el espacio: Complex phenomena in spatially extended systems.
Degree: 2011, Universidad de Cantabria
URL: http://hdl.handle.net/10902/1601
► RESUMEN: Uno de los aspectos más fascinantes del mundo que nos rodea es la gran variedad de escalas a las que tienen lugar los diversos…
(more)
▼ RESUMEN: Uno de los aspectos más fascinantes del mundo que nos rodea es la gran variedad de escalas a las que tienen lugar los diversos fenómenos. En muchos casos esta diversidad pone de manifiesto la estructura fractal de la naturaleza y podemos hablar entonces de fenómenos complejos, en los que eventos de diferentes magnitudes no pueden analizarse de manera independiente.
Dicha complejidad emerge como un fenómeno cooperativo a escalas microscópicas, que produce un complejo comportamiento macroscópico caracterizado por correlaciones de largo alcance e invarianza de escala. Aparecen así conceptos como leyes de escalado, universalidad y renormalización, pilares fundamentales dentro de la Física Estadística.
El abanico de fenómenos complejos es muy amplio, y abarca sistemas de muy diversas disciplinas que van desde la Física más ortodoxa hasta la Biología, Sociología, Geología e, incluso, Economía. Esta Tesis se centra en fenómenos complejos extendidos en el espacio. En concreto hemos focalizado nuestra labor en tres grandes temas que constituyen importantes focos de interés dentro de la Mecánica Estadística: Crecimiento de Interfases, Sociofísica y Redes Complejas.
Advisors/Committee Members: López Martín, Juan Manuel (advisor), Universidad de Cantabria (other).
Subjects/Keywords: Phase transitions
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APA ·
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sánchez de la Lama, M. (2011). Fenómenos complejos en sistemas extendidos en el espacio: Complex phenomena in spatially extended systems. (Doctoral Dissertation). Universidad de Cantabria. Retrieved from http://hdl.handle.net/10902/1601
Chicago Manual of Style (16th Edition):
Sánchez de la Lama, Marta. “Fenómenos complejos en sistemas extendidos en el espacio: Complex phenomena in spatially extended systems.” 2011. Doctoral Dissertation, Universidad de Cantabria. Accessed March 04, 2021.
http://hdl.handle.net/10902/1601.
MLA Handbook (7th Edition):
Sánchez de la Lama, Marta. “Fenómenos complejos en sistemas extendidos en el espacio: Complex phenomena in spatially extended systems.” 2011. Web. 04 Mar 2021.
Vancouver:
Sánchez de la Lama M. Fenómenos complejos en sistemas extendidos en el espacio: Complex phenomena in spatially extended systems. [Internet] [Doctoral dissertation]. Universidad de Cantabria; 2011. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/10902/1601.
Council of Science Editors:
Sánchez de la Lama M. Fenómenos complejos en sistemas extendidos en el espacio: Complex phenomena in spatially extended systems. [Doctoral Dissertation]. Universidad de Cantabria; 2011. Available from: http://hdl.handle.net/10902/1601
NSYSU
7.
Lin, Yi-Ting.
Studies of polymer stabilized blue phase liquid crystals phase grating.
Degree: PhD, Electro-Optical Engineering, 2013, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0705113-161901
► ããThe advantages of liquid crystal (LC) diffraction gratings include their low cost and low-power electrical switchability. Liquid crystal is easily controlled by exploiting common electro-optical…
(more)
▼ ããThe advantages of liquid crystal (LC) diffraction gratings include their low cost and low-power electrical switchability. Liquid crystal is easily controlled by exploiting common electro-optical behaviors. To form a
phase grating profile, the LC must have a periodically varying refractive index. Previous works by the authors showed that, because of the intrinsic optical anisotropy of LCs, the optical properties of
these gratings are highly dependent on the polarization state of incident light. Some polarization-independent gratings use conventional orthogonally aligned nematic LC in one cell. However, even though the diffraction intensity is independent of light polarization, the diffraction beam polarization still depends on the angle between the polarization of the incident beam and the LC alignment.
ããBlue phases (BPs) have been in chiral liquid crystals between the cholesteric and isotropic phases The BP of a self-assembled three-dimensional cubic structure with lattice periods of several hundred nanometers exhibits not only selective Bragg reflections of light in the visible wavelength, but also optical isotropy owing to its highly symmetric molecular structure. A BPLC is optically isotropic when no voltage is
applied, and
phase-only modulation occurs when an electric field is applied parallel to the direction of propagated light. However, the use of in-plane switching (IPS) electrodes makes the grating polarization-dependent and retains background diffraction from the patterned electrode.
ããThis dissertation discusses the control of a polarization-independent and rapidly responding polymer-stabilized blue
phase liquid crystal (PSBP)
phase grating by exploiting the variation in the voltage-induced birefringence of the LC under a varying
phase. The electro-optical properties, including the voltage-dependent diffraction intensity, polarization-independence and response time, are also discussed.
ããFirstly, the hybrid PSBP liquid crystal
phase grating was studied. This grating consists of hybrid PSBPs with different Kerr constants that are determined by varied
phase separation conditions. When cured at a high temperature, a loose PSBP network is formed and a large Kerr effect is obtained. Accordingly, the electric-field-induced birefringence of PSBPI is lower than that of PSBPII at a given driving voltage. The
non-patterned electrode and optical isotropy of both PSBPI and PSBPII enable elimination of the diffraction effect when the voltage is off. The diffraction intensity increases with the applied voltage up to a maximum at 150V.
ããSecondly, a polarization-independent and rapidly responding dye-doped (DD) PSBP liquid crystal
phase grating was realized with two different
phase states. The non-patterned electrode and the optical isotropy of the PSBP completely eliminate the diffraction effect when the voltage is off. The diffraction intensity can be increased by applying a uniform electrical field, which induces a
phase difference in the DDPSBP. The diffraction efficiency exceeds 6%, which is 7-fold higher than…
Advisors/Committee Members: Chin-Ping Yu (chair), Wei Lee (chair), Kuang-Yao Lo (chair), Chi-Yen Huang (chair), Tsung-Hsien Lin (committee member), Andy Fuh (chair).
Subjects/Keywords: azobenzene; phase grating; blue phase; Liquid crystal
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APA ·
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MLA ·
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lin, Y. (2013). Studies of polymer stabilized blue phase liquid crystals phase grating. (Doctoral Dissertation). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0705113-161901
Chicago Manual of Style (16th Edition):
Lin, Yi-Ting. “Studies of polymer stabilized blue phase liquid crystals phase grating.” 2013. Doctoral Dissertation, NSYSU. Accessed March 04, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0705113-161901.
MLA Handbook (7th Edition):
Lin, Yi-Ting. “Studies of polymer stabilized blue phase liquid crystals phase grating.” 2013. Web. 04 Mar 2021.
Vancouver:
Lin Y. Studies of polymer stabilized blue phase liquid crystals phase grating. [Internet] [Doctoral dissertation]. NSYSU; 2013. [cited 2021 Mar 04].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0705113-161901.
Council of Science Editors:
Lin Y. Studies of polymer stabilized blue phase liquid crystals phase grating. [Doctoral Dissertation]. NSYSU; 2013. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0705113-161901
North Carolina State University
8.
Cassidy, Daniel Anthony.
Numerical and Experimental Investigations of Mixed Convection in Solid-Liquid Flow for MicroPCM Applications.
Degree: PhD, Mechanical Engineering, 2009, North Carolina State University
URL: http://www.lib.ncsu.edu/resolver/1840.16/5199
► The present study is both a numerical and experimental investigation into the two phase flow of a microPCM fluid in a circular tube with mixed…
(more)
▼ The present study is both a numerical and experimental investigation into the two
phase flow of a microPCM fluid in a circular tube with mixed convection. The PCM was octacosane encapsulated by a polyethylene shell to form a spherical particle with an average diameter of 20 microns. The microPCM particles were suspended in a 50 / 50 ethylene glycol water mixture. The flow was through a 0.00775 m diameter copper tube with a length of approximately 0.75m. A constant wall heat flux was supplied by an electric resistance wire. The flow was gravity fed with a pumped circulation to maintain a constant pressure head. Experimental measurements were made of the tube outer wall at the top and bottom of the copper tube. Numerically an incompressible flow model was used with an Eulerian - Eulerian method to solve the two
phase momentum and energy equations. The numerical model was verified using experimental data of single
phase flow with mixed convection available in literature and was also verified by thermal results of both single
phase and two
phase flow from the experimental work in the current investigation.
Through the numerical investigation of the experimental conditions it was found that when the slurry was not cooled to a temperature far enough below the inlet temperature a supercooling effect did not allow a full use of the latent heat available in the octacosane microPCM, only about 50% of the total latent heat was used in one case. Further numerical investigations included tube wall material in which stainless steel was compared to the copper tubing used in the experiment. The inclusion of the solid
phase buoyancy term was found to affect the thermal solution. A comparison was also made of microPCM flow rates in which the Reynolds number, the mass flow rate, and the pump power were each held constant and the solutions compared. It was then recommended that a constant pump power be used as a basis for comparison. A parametric study was also completed in which the Rayleigh number and the Stefan number were both varied to find the effects on the thermal and hydrodynamic solution.
Advisors/Committee Members: Dr. Richard D. Gould, Committee Chair (advisor), Dr. Kevin M. Lyons, Committee Member (advisor), Dr. Andrey V. Kuznetsov, Committee Member (advisor), Dr. James W. Leach, Committee Member (advisor).
Subjects/Keywords: phase change material; two phase flow; octacosane
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APA (6th Edition):
Cassidy, D. A. (2009). Numerical and Experimental Investigations of Mixed Convection in Solid-Liquid Flow for MicroPCM Applications. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/5199
Chicago Manual of Style (16th Edition):
Cassidy, Daniel Anthony. “Numerical and Experimental Investigations of Mixed Convection in Solid-Liquid Flow for MicroPCM Applications.” 2009. Doctoral Dissertation, North Carolina State University. Accessed March 04, 2021.
http://www.lib.ncsu.edu/resolver/1840.16/5199.
MLA Handbook (7th Edition):
Cassidy, Daniel Anthony. “Numerical and Experimental Investigations of Mixed Convection in Solid-Liquid Flow for MicroPCM Applications.” 2009. Web. 04 Mar 2021.
Vancouver:
Cassidy DA. Numerical and Experimental Investigations of Mixed Convection in Solid-Liquid Flow for MicroPCM Applications. [Internet] [Doctoral dissertation]. North Carolina State University; 2009. [cited 2021 Mar 04].
Available from: http://www.lib.ncsu.edu/resolver/1840.16/5199.
Council of Science Editors:
Cassidy DA. Numerical and Experimental Investigations of Mixed Convection in Solid-Liquid Flow for MicroPCM Applications. [Doctoral Dissertation]. North Carolina State University; 2009. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5199
9.
Gouraud, Fanny.
Influence des transformations de phase de la zircone sur le comportement thermomécanique de réfractaires à très haute teneur en zircone : Influence of zirconia phase transitions on the thermo-mechanical behavior of high zirconia refractories.
Degree: Docteur es, Matériaux Céramiques et Traitement de Surface, 2016, Limoges
URL: http://www.theses.fr/2016LIMO0110
► Ces travaux de thèse, réalisés dans le cadre du programme de recherche ASZTech, portent sur l’étude de deux réfractaires électrofondus : un matériau Alumine-Zircone-Silice (AZS)…
(more)
▼ Ces travaux de thèse, réalisés dans le cadre du programme de recherche ASZTech, portent sur l’étude de deux réfractaires électrofondus : un matériau Alumine-Zircone-Silice (AZS) et un produit à Très Haute Teneur en Zircone (THTZ), destinés à l’industrie verrière. La zircone étant non stabilisée, ces réfractaires subissent donc, lors de l’étape de recuisson (refroidissement), la transformation quadratique (Q) à monoclinique (M) de la zircone qui, de par sa forte expansion volumique, est une source d’endommagement. L’objectif de cette étude a consisté à caractériser, au cours de traitements thermiques représentatifs, le comportement thermomécanique de ces matériaux et à établir des corrélations avec les évolutions microstructurales rencontrées. En étudiant leurs comportements sous sollicitations thermiques par des techniques acoustiques, l’impact de la transformation Q-M de la zircone sur le développement de l’endommagement a été mis en évidence. En s’intéressant particulièrement au comportement mécanique au passage de cette transformation, la présence d’un phénomène de plasticité de transformation (TRIP) a été confirmée. Outre le phénomène de TRIP qui participe à la relaxation des contraintes au passage de la transformation de phase, un phénomène d’endommagement diffus, offrant également une capacité d’accommodation, a été identifié pour le matériau THTZ. Au final, ces données ont permis d’améliorer le modèle de simulation numérique décrivant l’étape de recuisson de blocs industriels. En outre, la robustesse de ce modèle pourra maintenant être validée par confrontation à des mesures expérimentales de contraintes résiduelles réalisées au cours de cette étude.
This thesis, carried out under the research program ASZTech, focuses on the study of two fused cast refractories: an Alumina-Zirconia-Silica (AZS) product and a product with very High content of Zirconia (HZ), used in glass industry. These refractories containing non-stabilized zirconia are therefore subjected, during the annealing step (cooling), to the tetragonal (T) to the monoclinic (M) phase transition of zirconia associated with a very high volumetric expansion which is a source of stresses. This study aims at characterizing, during representative thermal treatments, the thermo-mechanical behavior of these materials, in correlation with the detected microstructural evolutions. Thanks to the analysis of their behavior under thermal stresses by acoustic techniques, the effect of the T-M transition of zirconia on the development of damage has been highlighted. In particular, the occurrence of a TRansformation Induced Plasticity (TRIP) phenomenon during the zirconia phase transition has been identified and characterized thanks to cooling tests under mechanical stress. In addition to this TRIP phenomenon which allows to relax the mechanical stresses induced during the phase transition, a diffuse damage phenomenon has been also identified for HZ product. Eventually, these data have led to an improvement of the numerical model which simulates the annealing step…
Advisors/Committee Members: Chotard, Thierry (thesis director), Huger, Marc (thesis director), Antou, Guy (thesis director).
Subjects/Keywords: Transformations de phase; Phase transitions; 620.189 35
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APA (6th Edition):
Gouraud, F. (2016). Influence des transformations de phase de la zircone sur le comportement thermomécanique de réfractaires à très haute teneur en zircone : Influence of zirconia phase transitions on the thermo-mechanical behavior of high zirconia refractories. (Doctoral Dissertation). Limoges. Retrieved from http://www.theses.fr/2016LIMO0110
Chicago Manual of Style (16th Edition):
Gouraud, Fanny. “Influence des transformations de phase de la zircone sur le comportement thermomécanique de réfractaires à très haute teneur en zircone : Influence of zirconia phase transitions on the thermo-mechanical behavior of high zirconia refractories.” 2016. Doctoral Dissertation, Limoges. Accessed March 04, 2021.
http://www.theses.fr/2016LIMO0110.
MLA Handbook (7th Edition):
Gouraud, Fanny. “Influence des transformations de phase de la zircone sur le comportement thermomécanique de réfractaires à très haute teneur en zircone : Influence of zirconia phase transitions on the thermo-mechanical behavior of high zirconia refractories.” 2016. Web. 04 Mar 2021.
Vancouver:
Gouraud F. Influence des transformations de phase de la zircone sur le comportement thermomécanique de réfractaires à très haute teneur en zircone : Influence of zirconia phase transitions on the thermo-mechanical behavior of high zirconia refractories. [Internet] [Doctoral dissertation]. Limoges; 2016. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2016LIMO0110.
Council of Science Editors:
Gouraud F. Influence des transformations de phase de la zircone sur le comportement thermomécanique de réfractaires à très haute teneur en zircone : Influence of zirconia phase transitions on the thermo-mechanical behavior of high zirconia refractories. [Doctoral Dissertation]. Limoges; 2016. Available from: http://www.theses.fr/2016LIMO0110
Oregon State University
10.
Elshazly, Amr.
Performance enhancement techniques for low power digital phase locked loops.
Degree: PhD, Electrical and Computer Engineering, 2012, Oregon State University
URL: http://hdl.handle.net/1957/31116
► Desire for low-power, high performance computing has been at core of the symbiotic union between digital circuits and CMOS scaling. While digital circuit performance improves…
(more)
▼ Desire for low-power, high performance computing has been at core of the symbiotic union between digital circuits and CMOS scaling. While digital circuit performance improves with device scaling, analog circuits have not gained these benefits. As a result, it has become necessary to leverage increased digital circuit performance to mitigate analog circuit deficiencies in nanometer scale CMOS in order to realize world class analog solutions.
In this thesis, both circuit and system enhancement techniques to improve performance of clock generators are discussed. The following techniques were developed: (1) A digital PLL that employs an adaptive and highly efficient way to cancel the effect of supply noise, (2) a supply regulated DPLL that uses low power regulator and improves supply noise rejection, (3) a digital multiplying DLL that obviates the need for high-resolution TDC while achieving sub-picosecond jitter and excellent supply noise immunity, and (4) a high resolution TDC based on a switched ring oscillator, are presented. Measured results obtained from the prototype chips are presented to illustrate the proposed design techniques.
Advisors/Committee Members: Hanumolu, Pavan Kumar (advisor), Temes, Gabor (committee member).
Subjects/Keywords: Phase locked loops; Phase-locked loops
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APA (6th Edition):
Elshazly, A. (2012). Performance enhancement techniques for low power digital phase locked loops. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/31116
Chicago Manual of Style (16th Edition):
Elshazly, Amr. “Performance enhancement techniques for low power digital phase locked loops.” 2012. Doctoral Dissertation, Oregon State University. Accessed March 04, 2021.
http://hdl.handle.net/1957/31116.
MLA Handbook (7th Edition):
Elshazly, Amr. “Performance enhancement techniques for low power digital phase locked loops.” 2012. Web. 04 Mar 2021.
Vancouver:
Elshazly A. Performance enhancement techniques for low power digital phase locked loops. [Internet] [Doctoral dissertation]. Oregon State University; 2012. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1957/31116.
Council of Science Editors:
Elshazly A. Performance enhancement techniques for low power digital phase locked loops. [Doctoral Dissertation]. Oregon State University; 2012. Available from: http://hdl.handle.net/1957/31116
KTH
11.
Bhogireddy, Venkata Sai Pavan Kumar.
Phase Field modeling of sigma phase transformation in duplex stainless steels : Using FiPy-Finite Volume PDE solver.
Degree: Materials Science and Engineering, 2013, KTH
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161712
► Duplex Stainless Steels (DSS) are used extensively in various industrial applications where the properties of both austenite and ferrite steels are required. Higher mechanical…
(more)
▼ Duplex Stainless Steels (DSS) are used extensively in various industrial applications where the properties of both austenite and ferrite steels are required. Higher mechanical strength and superior corrosion resistance are the advantages of DSS. One of the main drawbacks for Duplex steels is precipitation of sigma phase and other intermetallic phases adversely affecting the mechanical strength and the corrosion behavior of the steels. The precipitation of these secondary phases and the associated brittleness can be due to improper heat treatment. The instability in the microstructure of Duplex stainless steels can be studied by understanding the phase transformations especially the ones involving sigma phase. To reduce the time and effort to be put in for experimental work, computational simulations are used to get an initial understanding on the phase transformations. The present thesis work is on the phase transformations involving sigma phase for Fe-Cr system and Fe-Cr-Ni system using theoretical approach in 1D and 2D geometries. A phase field model is implemented for the microstructural evolution in DSS in combination with thermodynamic data collected from the Thermo-Calc software. The Wheeler Boettinger McFadden (WBM) model is used for Gibbs energy interpolation of the system. FiPy- Finite volume PDE solver written in python is used to simulate the phase transformation conditions first in Fe-Cr system for ferrite-austenite and ferrite-sigma phase transformations. It is then repeated for Fe-Cr-Ni ternary system. In the present study a model was developed for deriving Gibbs energy expression for sigma phase based on the common tangent condition. This model can be used to describe composition constrained phases and stoichiometric phases using the WBM model in phase field modeling. Cogswell’s theory of using phase order variable instead of an interpolating polynomial in the expression for Gibbs energy of whole system is also tried.
Subjects/Keywords: Phase field; Duplex Stainless steels; Sigma phase
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Export
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APA (6th Edition):
Bhogireddy, V. S. P. K. (2013). Phase Field modeling of sigma phase transformation in duplex stainless steels : Using FiPy-Finite Volume PDE solver. (Thesis). KTH. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161712
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):
Bhogireddy, Venkata Sai Pavan Kumar. “Phase Field modeling of sigma phase transformation in duplex stainless steels : Using FiPy-Finite Volume PDE solver.” 2013. Thesis, KTH. Accessed March 04, 2021.
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161712.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bhogireddy, Venkata Sai Pavan Kumar. “Phase Field modeling of sigma phase transformation in duplex stainless steels : Using FiPy-Finite Volume PDE solver.” 2013. Web. 04 Mar 2021.
Vancouver:
Bhogireddy VSPK. Phase Field modeling of sigma phase transformation in duplex stainless steels : Using FiPy-Finite Volume PDE solver. [Internet] [Thesis]. KTH; 2013. [cited 2021 Mar 04].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161712.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bhogireddy VSPK. Phase Field modeling of sigma phase transformation in duplex stainless steels : Using FiPy-Finite Volume PDE solver. [Thesis]. KTH; 2013. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161712
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
12.
Dutto, Vincent.
Mesure des défauts de forme de microballons par imagerie X : exploitation du phénomène de constraste de phase : Microshells form defects measurements by radiography using the phase contrast phenomenon.
Degree: Docteur es, Mathématiques, 2018, Toulon
URL: http://www.theses.fr/2018TOUL0013
► Depuis l'arrêt définitif des essais nucléaires, la Direction des Applications Militaires (DAM) du CEA s'appuiesur le triptyque modélisation physique - validation expérimentale - simulation numérique…
(more)
▼ Depuis l'arrêt définitif des essais nucléaires, la Direction des Applications Militaires (DAM) du CEA s'appuiesur le triptyque modélisation physique - validation expérimentale - simulation numérique pour comprendre,prévoir et garantir le fonctionnement des armes nucléaires. Parmi les grands équipements contribuant à lavalidation des modèles physiques implémentés dans les logiciels de calcul, le Laser MegaJoule permetd'étudier expérimentalement des phénomènes de même nature que ceux intervenant dans les armes. La familled'objets expérimentés sur cette installation est dénommée « microcibles laser». Les microballons intégrés dansces microcibles sont caractérisés par des techniques de radiographie X. Les brusques variations de niveau degris observées sur les clichés X de microballons témoignent de la 'présence d'un phénomène de contraste dephase, contraste s'ajoutant au contraste d'absorption. L'information contenue dans ce phénomène est utiliséepour une détection de contours du microballon radiographié. Les points trouvés lors de la détection de contourssont alors utilisés par un algorithme d'estimation des défauts de formes des surfaces des microballons. Uneétude paramétrique permet d'identifier le nombre de clichés nécessaire à l'estimation des défauts de forme enfonction du nombre de modes souhaités. L'incertitude de la méthode d'estimation est calculée permettant lacaractérisation complète du microballon.
Since 1996, the CEA's Military Applications Division (DAM) guaranties the reliability and safety of Frenchnuclear warheads without conducting any further nuclear test. It relies particularly on major facilities forvalidating the equations used to model the functioning of nuclear weapons. Among them, the Megajoule Laser(LMJ) allows studying experimentally, as "laboratory" measurements, representative phenomena gatheringtime·scale and space distribution of extreme temperature and pressure conditions. These experiments are ledwith millimetric objects named microshells. Before experimenting them, these microshells are characterizedusing X·rays technics. On the radiographies, one can observe straight gray level variations which are generatedby the phase contrast phenomenon added to x·rays absorption contrast. Information included in this formercontrast is used to sharply determine microshell's edges. The delimiting points of these edges are thenintegrated as input data to compute microshell's surface form defects. A study is also led to determine theoptimized number of radiographies needed for estimating the search defect modes. Measurement uncertainty isfinally evaluated, thus giving a complete microshell's characterization.
Advisors/Committee Members: Busvelle, Eric (thesis director), Gauthier, Jean-Paul André (thesis director).
Subjects/Keywords: Microballon; Contraste de phase; Microshell; Phase contrast
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APA (6th Edition):
Dutto, V. (2018). Mesure des défauts de forme de microballons par imagerie X : exploitation du phénomène de constraste de phase : Microshells form defects measurements by radiography using the phase contrast phenomenon. (Doctoral Dissertation). Toulon. Retrieved from http://www.theses.fr/2018TOUL0013
Chicago Manual of Style (16th Edition):
Dutto, Vincent. “Mesure des défauts de forme de microballons par imagerie X : exploitation du phénomène de constraste de phase : Microshells form defects measurements by radiography using the phase contrast phenomenon.” 2018. Doctoral Dissertation, Toulon. Accessed March 04, 2021.
http://www.theses.fr/2018TOUL0013.
MLA Handbook (7th Edition):
Dutto, Vincent. “Mesure des défauts de forme de microballons par imagerie X : exploitation du phénomène de constraste de phase : Microshells form defects measurements by radiography using the phase contrast phenomenon.” 2018. Web. 04 Mar 2021.
Vancouver:
Dutto V. Mesure des défauts de forme de microballons par imagerie X : exploitation du phénomène de constraste de phase : Microshells form defects measurements by radiography using the phase contrast phenomenon. [Internet] [Doctoral dissertation]. Toulon; 2018. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2018TOUL0013.
Council of Science Editors:
Dutto V. Mesure des défauts de forme de microballons par imagerie X : exploitation du phénomène de constraste de phase : Microshells form defects measurements by radiography using the phase contrast phenomenon. [Doctoral Dissertation]. Toulon; 2018. Available from: http://www.theses.fr/2018TOUL0013
University of North Texas
13.
Devaraj, Arun.
Phase Separation and Second Phase Precipitation in Beta Titanium Alloys.
Degree: 2011, University of North Texas
URL: https://digital.library.unt.edu/ark:/67531/metadc67975/
► The current understanding of the atomic scale phenomenon associated with the influence of beta phase instabilities on the evolution of microstructure in titanium alloys is…
(more)
▼ The current understanding of the atomic scale phenomenon associated with the influence of beta
phase instabilities on the evolution of microstructure in titanium alloys is limited due to their complex nature. Such beta
phase instabilities include
phase separation and precipitation of nano-scale omega and alpha phases in the beta matrix. The initial part of the present study focuses on omega precipitation within the beta matrix of model binary titanium molybdenum (Ti-Mo) alloys. Direct atomic scale observation of pre-transition omega-like embryos in quenched alloys, using aberration-corrected high resolution scanning transmission electron microscopy and atom probe tomography (APT) was compared and contrasted with the results of first principles computations performed using the Vienna ab initio simulation package (VASP) to present a novel mechanism of these special class of
phase transformation. Thereafter the beta
phase separation and subsequent alpha
phase nucleation in a Ti-Mo-Al ternary alloy was investigated by coupling in-situ high energy synchrotron x-ray diffraction with ex-situ characterization studies performed using aberration corrected transmission electron microscopy and APT to develop a deeper understanding of the mechanism of transformation. Subsequently the formation of the omega
phase in the presence of simultaneous development of compositional
phase separation within the beta matrix
phase of a Ti-10V-6Cu (wt%) alloy during continuous cooling has been investigated using a combination of transmission electron microscopy and atom probe tomography. The results of these investigations provided novel insights into the mechanisms of solid-state transformations in metallic systems by capturing the earliest stages of nucleation at atomic to near atomic spatial and compositional resolution.
Advisors/Committee Members: Banerjee, Rajarshi, Srivilliputhur, Srinivasan, Needleman, Alan, Nag, SoumyA, Fraser, Hamish.
Subjects/Keywords: Titanium alloys; phase transformation; phase separation
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University of Louisville
14.
Ray, Herman E.
Design and inference in phase II/III clinical trials incorporating monitoring of multiple endpoints.
Degree: PhD, 2011, University of Louisville
URL: 10.18297/etd/1189
;
https://ir.library.louisville.edu/etd/1189
► The phase II clinical trial is a critical step in the drug development process. In the oncology setting, phase II studies typically evaluate one primary…
(more)
▼ The
phase II clinical trial is a critical step in the drug development process. In the oncology setting,
phase II studies typically evaluate one primary endpoint, which is efficacy. In practice, a binary measurement representing the response to the new treatment defines the efficacy. The single-arm, multiple-stage designs are popular and the Simon 2-Stage design is preferred. Although the study designs evaluate the efficacy, the
subject's safety is an important concern. Safety is monitored through the number of grade 3 or grade 4 toxic events. The
phase II clinical trial design based on the primary endpoint is typically augmented with an ad hoc monitoring rule. The studies are designed in two steps. First, the sample size and critical values are determined based on the primary endpoint. Then an ad hoc toxicity monitoring rule is applied to the study. Previous authors recommended a method to monitor toxic events after each patient is enrolled which is also known as continuous toxicity monitoring. A trial designed at the JG Brown Cancer Center combined the Simon 2-Stage design with continuous toxicity monitoring. We describe how to integrate the continuous toxicity monitoring methodology with the Simon 2-Stage design for response. Theoretical justification is given for the nominal size, power, probability of early termination (PET), and average sample size (ASN) of the combined testing procedure. A series of simulations were conducted to investigate the performance of the combined procedure. We discover that the type I error rate, type II error rate, PET, and ASN are
subject to the correlation between toxicity and response. In fact, the study may have a smaller type I error rate than expected. The theoretical expressions derived to describe the operating characteristics of the combined procedure were utilized to create a new flexible, bivariate, multistage clinical trial. The design is considered flexible because it can monitor toxicity on a different schedule than response. An example is considered in which toxicity is measured after four equally spaced intervals and the response is evaluated only at the second and fourth toxicity examinations. This example corresponds to a data monitoring committee's meeting schedule that may happen every 6 months over a two year span. The effect of the correlation on the type I and type II error rates is examined through simulation. The simulations also examine the power over the range of response rates with a fixed toxicity rate in the alternative region and vice-versa. There are several single-arm, multiple-stage clinical trial designs that consider multiple endpoints at the same time. A subset of the designs includes those that consider both efficacy and toxicity as binary endpoints. A common problem, considered after the conduct of the trial, is appropriate inference given the repeated examinations of the multiple endpoints. We propose a uniformly minimum variance unbiased estimator (UMVUE) for the response in a multistage clinical trial design incorporating toxicity effects.…
Advisors/Committee Members: Rai, Shesh Nath.
Subjects/Keywords: Clinical trial; Bivariate; Phase II; Phase III
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APA ·
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MLA ·
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Export
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APA (6th Edition):
Ray, H. E. (2011). Design and inference in phase II/III clinical trials incorporating monitoring of multiple endpoints. (Doctoral Dissertation). University of Louisville. Retrieved from 10.18297/etd/1189 ; https://ir.library.louisville.edu/etd/1189
Chicago Manual of Style (16th Edition):
Ray, Herman E. “Design and inference in phase II/III clinical trials incorporating monitoring of multiple endpoints.” 2011. Doctoral Dissertation, University of Louisville. Accessed March 04, 2021.
10.18297/etd/1189 ; https://ir.library.louisville.edu/etd/1189.
MLA Handbook (7th Edition):
Ray, Herman E. “Design and inference in phase II/III clinical trials incorporating monitoring of multiple endpoints.” 2011. Web. 04 Mar 2021.
Vancouver:
Ray HE. Design and inference in phase II/III clinical trials incorporating monitoring of multiple endpoints. [Internet] [Doctoral dissertation]. University of Louisville; 2011. [cited 2021 Mar 04].
Available from: 10.18297/etd/1189 ; https://ir.library.louisville.edu/etd/1189.
Council of Science Editors:
Ray HE. Design and inference in phase II/III clinical trials incorporating monitoring of multiple endpoints. [Doctoral Dissertation]. University of Louisville; 2011. Available from: 10.18297/etd/1189 ; https://ir.library.louisville.edu/etd/1189
Oregon State University
15.
Arakali, Abhijith.
Low-power techniques for supply-noise mitigation in phase-locked
loops.
Degree: PhD, Electrical and Computer Engineering, 2010, Oregon State University
URL: http://hdl.handle.net/1957/14281
► Modern day digital systems employ frequency synthesizers to provide a common clock to the system. They are undergoing large scale integration due to which, mitigation…
(more)
▼ Modern day digital systems employ frequency
synthesizers to provide a common clock to the system.
They are undergoing large scale integration due to which, mitigation
of the effect of noise on power supply has become a major design consideration
in clocking circuits. Rapid scaling of CMOS technology mandates the
design of frequency synthesizers in a low supply voltage environment.
Maintaining the supply noise immunity of clocking circuits in low-voltage
processes is particularly challenging.
In this thesis, techniques to mitigate the effect of supply-noise
in frequency synthesizers are
explored. The ring-oscillator based frequency synthesizer
is an important part of many clocking circuits.
They are used in various digital communication systems and as a
building block in high speed signalling systems.
They suffer from high sensitivity to power supply noise thereby requiring
careful design considerations to improve its supply noise immunity.
In light of the above, an attempt has been made to
improve the immunity of the ring-oscillator based frequency synthesizer
to noise on the supply voltage. The effect of noise on
the supplies of other building blocks of a frequency synthesizer,
though not as pronounced as that of noise on the ring-oscillator supply,
is quite significant. Analysis of effect of power supply noise on
various building blocks of the frequency synthesizer are presented.
Also, techniques to effectively reduce the effect of power supply noise
on the performance of the frequency synthesizer are presented.
Measured results from proof-of-concept ICs are presented to illustrate the
effectiveness of the proposed techniques.
Clock and data recovery (CDR) circuits which utilize ring-oscillators are
also highly sensitive to power supply noise. Measurement of CDR jitter
tolerance without the use of expensive equipment is another challenge involved
in the design of CDRs. An on-chip jitter tolerance measurement technique is
presented wherein, a
phase averaging dual loop CDR architecture is used
which comprises of a
phase-locked loop (PLL) inside the CDR loop.
Previously proposed idea of using oversampling in this architecture has proven
to considerably
reduce power consumption in this CDR architecture. In this thesis, an
attempt has been made to further reduce the power consumption.
The PLL in this CDR architecture utilizes the proposed supply regulated PLL
architecture in order to minimize the bit-error rate (BER) of the CDR due to
power supply noise.
Advisors/Committee Members: Hanumolu, Pavan Kumar (advisor), Mayaram, Kartikeya (committee member).
Subjects/Keywords: Phase-locked loops
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APA (6th Edition):
Arakali, A. (2010). Low-power techniques for supply-noise mitigation in phase-locked
loops. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/14281
Chicago Manual of Style (16th Edition):
Arakali, Abhijith. “Low-power techniques for supply-noise mitigation in phase-locked
loops.” 2010. Doctoral Dissertation, Oregon State University. Accessed March 04, 2021.
http://hdl.handle.net/1957/14281.
MLA Handbook (7th Edition):
Arakali, Abhijith. “Low-power techniques for supply-noise mitigation in phase-locked
loops.” 2010. Web. 04 Mar 2021.
Vancouver:
Arakali A. Low-power techniques for supply-noise mitigation in phase-locked
loops. [Internet] [Doctoral dissertation]. Oregon State University; 2010. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1957/14281.
Council of Science Editors:
Arakali A. Low-power techniques for supply-noise mitigation in phase-locked
loops. [Doctoral Dissertation]. Oregon State University; 2010. Available from: http://hdl.handle.net/1957/14281
Oregon State University
16.
Black, Corrie D.
The investigation of dipicolinic acid diamide derivatives for the separation of actinides and lanthanides using solid phase extraction chromatography.
Degree: MS, Radiation Health Physics, 2011, Oregon State University
URL: http://hdl.handle.net/1957/21872
► An alternative extractant for the TRUEX/UNEX process was investigated in solid phase extraction chromatography. The para and ortho isomers of diamides derivatives of dipicolinic acid…
(more)
▼ An alternative extractant for the TRUEX/UNEX process was investigated in solid
phase extraction chromatography. The para and ortho isomers of diamides derivatives of dipicolinic acid (N,N'-diethyl-N,N'-ditolyl-dipicolinamide, EtTDPA) have been found in the past to effectively separate actinides from lanthanides in solvent extraction and were successfully impregnated on two uncoated, inert macroporous polymeric support resin types. The ortho resins consistently yielded higher extractions while the para resin consistently yielded higher Am/Eu separations. These findings were consistent with past solvent extraction experiments and suggest the versatility of these extractants in a variety of applications. The use of complexing agents were also considered both in the eluent and on the resin and found to change the extraction properties of the resin enough to warrant further investigation.
Advisors/Committee Members: Paulenova, Alena (advisor), Mincher, Bruce (committee member).
Subjects/Keywords: Solid Phase Extraction
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APA (6th Edition):
Black, C. D. (2011). The investigation of dipicolinic acid diamide derivatives for the separation of actinides and lanthanides using solid phase extraction chromatography. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/21872
Chicago Manual of Style (16th Edition):
Black, Corrie D. “The investigation of dipicolinic acid diamide derivatives for the separation of actinides and lanthanides using solid phase extraction chromatography.” 2011. Masters Thesis, Oregon State University. Accessed March 04, 2021.
http://hdl.handle.net/1957/21872.
MLA Handbook (7th Edition):
Black, Corrie D. “The investigation of dipicolinic acid diamide derivatives for the separation of actinides and lanthanides using solid phase extraction chromatography.” 2011. Web. 04 Mar 2021.
Vancouver:
Black CD. The investigation of dipicolinic acid diamide derivatives for the separation of actinides and lanthanides using solid phase extraction chromatography. [Internet] [Masters thesis]. Oregon State University; 2011. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1957/21872.
Council of Science Editors:
Black CD. The investigation of dipicolinic acid diamide derivatives for the separation of actinides and lanthanides using solid phase extraction chromatography. [Masters Thesis]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/21872
17.
Peters, Phillip.
Etude théorique de la réactivité de l’hydrogène avec CO, H2CO, H3COH à la surface des grains interstellaires : A Theoretical study of the reaction of hydrogen with CO, H2CO, CH3OH on the surfaces of interstellar dust grains.
Degree: Docteur es, Optique et Lasers, Physico-chimie, Atmosphère, 2012, Université Lille I – Sciences et Technologies
URL: http://www.theses.fr/2012LIL10125
► L'objectif de ce travail est de caractériser par des méthodes de chimie quantique de haute qualité les processus réactionnels impliquant H, CO, H2CO, H3COH et…
(more)
▼ L'objectif de ce travail est de caractériser par des méthodes de chimie quantique de haute qualité les processus réactionnels impliquant H, CO, H2CO, H3COH et H2O à la surface des grains interstellaires. En effet, H2CO et H3COH sont parmi les molécules organiques les plus abondantes dans les nuages moléculaires interstellaires. Il s’agit de la première étude décrivant les étapes conduisant au méthanol par hydrogénations successives de CO. En phase gazeuse, les méthodes multi-références ont été employées. Les calculs montrent que certaines étapes cruciales de la synthèse (formation de HCO) mettent en jeu des barrières d'activation significatives dans les conditions interstellaires. L’effet tunnel a aussi été pris en compte. Les mêmes réactions ont ensuite été étudiées sur des agrégats d'eau ou de CO. Ceux-ci ont été choisis comme surfaces modèles pour les grains interstellaires. Compte-tenu de la taille du système, les calculs ont été menés en utilisant la théorie DFT et la méthode MP2. Pour la formation de HCO, la présence d'un agrégat ne modifie pas l'énergie d'activation. En revanche, pour la formation de COH et H3CO, l'énergie d'activation est réduite et l'endo/exothermicité change. L'isomérisation HCOH-H2CO devient possible dans des agrégats d'eau. Ces résultats indiquent que l'état de surface et le flux d'atomes H peuvent avoir une influence notable, ouvrant d'autres voies non envisageables en phase gazeuse. Enfin, ces résultats seront intégrés dans le modèle astrophysique GRAINOBLE, ce qui permettra de tenir compte des différents intermédiaires qui pourraient potentiellement participer à la synthèse de ces deux molécules ainsi que d’autres plus complexes.
Throughout this work high level quantum chemistry methods have been used to investigate reactive processes involving: H, D, CO, H2CO, H3COH and H2O at model interstellar grains surfaces. This study has mainly focused upon the formation of the two most abundant Complex Organic Molecules (COMS), H2CO and H3COH. For the first time, all of the hydrogenation steps have been considered and treated with reliable methods in the gas phase, and in particular making use of multi-reference approaches such as MRCI+Q and MRMP2. Following the characterization of all the reactions in the gas phase, the same processes have been investigated within small molecular clusters using various density functionals and MP2. This was done as a preliminary attempt to model the icy grain mantles of interstellar dust grains. For some of the steps, such as the formation of HCO, the activation energy does not vary significantly between the gas phase and the clusters. In contrast, for other processes, such as the formation of COH, and H3CO, the activation energy is lowered and the exothermicity/endothermicity of the reaction changes. In addition, the isomerizations of some species, as for instance HCOH to H2CO, are also strongly affected by the presence of water. From the cluster calculations, we conclude that the arrangement of the surface molecules and the H flux may have a significant…
Advisors/Committee Members: Duflot, Denis (thesis director), Wiesenfeld, Laurent (thesis director), Toubin, Céline (thesis director).
Subjects/Keywords: Phase gazeuse; 523.02
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Manager
APA (6th Edition):
Peters, P. (2012). Etude théorique de la réactivité de l’hydrogène avec CO, H2CO, H3COH à la surface des grains interstellaires : A Theoretical study of the reaction of hydrogen with CO, H2CO, CH3OH on the surfaces of interstellar dust grains. (Doctoral Dissertation). Université Lille I – Sciences et Technologies. Retrieved from http://www.theses.fr/2012LIL10125
Chicago Manual of Style (16th Edition):
Peters, Phillip. “Etude théorique de la réactivité de l’hydrogène avec CO, H2CO, H3COH à la surface des grains interstellaires : A Theoretical study of the reaction of hydrogen with CO, H2CO, CH3OH on the surfaces of interstellar dust grains.” 2012. Doctoral Dissertation, Université Lille I – Sciences et Technologies. Accessed March 04, 2021.
http://www.theses.fr/2012LIL10125.
MLA Handbook (7th Edition):
Peters, Phillip. “Etude théorique de la réactivité de l’hydrogène avec CO, H2CO, H3COH à la surface des grains interstellaires : A Theoretical study of the reaction of hydrogen with CO, H2CO, CH3OH on the surfaces of interstellar dust grains.” 2012. Web. 04 Mar 2021.
Vancouver:
Peters P. Etude théorique de la réactivité de l’hydrogène avec CO, H2CO, H3COH à la surface des grains interstellaires : A Theoretical study of the reaction of hydrogen with CO, H2CO, CH3OH on the surfaces of interstellar dust grains. [Internet] [Doctoral dissertation]. Université Lille I – Sciences et Technologies; 2012. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2012LIL10125.
Council of Science Editors:
Peters P. Etude théorique de la réactivité de l’hydrogène avec CO, H2CO, H3COH à la surface des grains interstellaires : A Theoretical study of the reaction of hydrogen with CO, H2CO, CH3OH on the surfaces of interstellar dust grains. [Doctoral Dissertation]. Université Lille I – Sciences et Technologies; 2012. Available from: http://www.theses.fr/2012LIL10125
Texas A&M University
18.
Firat, Volkan H.
Evaluation and Improvement of Atmospheric Infrared Sounder (AIRS) Ice Cloud Retrievals.
Degree: MS, Atmospheric Sciences, 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155521
► Clouds are still one of the largest uncertainties of the current climate models. While satellites provide suitable global datasets for comparing with cloud properties derived…
(more)
▼ Clouds are still one of the largest uncertainties of the current climate models. While satellites provide suitable global datasets for comparing with cloud properties derived from models, satellite retrievals are inferences of cloud properties, rather than direct measurements, and therefore have errors. Therefore, it is important to evaluate satellite cloud products and gain advanced understanding of the products to accurately interpret the observations.
This study investigates Aqua AIRS version 6 Level 2 cloud thermodynamic
phase, ice cloud optical thickness, and ice cloud effective diameter, which released in April, 2013 and are available for all 13 years of the AIRS record. A filtering and gridding algorithm is used to create customized globally gridded datasets to evaluate the effects of satellite's viewing zenith angle, effective cloud fraction, cloud layers, cloud top temperature, time of the year, and geographic region.
Viewing zenith angle does not strongly affect AIRS ice-
phase, but higher viewing zenith angles lead to more water and fewer unknown pixels; the viewing zenith angle dependence is not strongly affected by the time of the year. Higher effective cloud fraction yields more ice- and water-
phase, and less unknown-
phase retrievals. Also, higher effective cloud fractions lead to greater values of ice cloud optical thickness. In addition, especially in high latitudes, ice-
phase frequency is greater for two-layer clouds than single-layer clouds. On the other hand, water- and unknown-
phase frequencies are greater for single layer clouds. Also, higher viewing zenith angles slightly decrease upper cloud top temperature. Approximately 90% of ice-
phase cases have upper cloud top temperature values between 210 K and 235 K, ~80% of water-
phase cases are found at 243-273 K upper cloud top temperature interval, and ~80% of the unknown cases have upper cloud top temperature values between 230 and 264 K. For ice cloud optical thickness and ice cloud effective diameter, no strong effects of satellite viewing zenith angle or cloud layering are observed.
Advisors/Committee Members: Nasiri, Shaima L (advisor), North, Gerald R (committee member), Filippi, Anthony M (committee member).
Subjects/Keywords: AIRS; clouds; phase
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APA (6th Edition):
Firat, V. H. (2015). Evaluation and Improvement of Atmospheric Infrared Sounder (AIRS) Ice Cloud Retrievals. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155521
Chicago Manual of Style (16th Edition):
Firat, Volkan H. “Evaluation and Improvement of Atmospheric Infrared Sounder (AIRS) Ice Cloud Retrievals.” 2015. Masters Thesis, Texas A&M University. Accessed March 04, 2021.
http://hdl.handle.net/1969.1/155521.
MLA Handbook (7th Edition):
Firat, Volkan H. “Evaluation and Improvement of Atmospheric Infrared Sounder (AIRS) Ice Cloud Retrievals.” 2015. Web. 04 Mar 2021.
Vancouver:
Firat VH. Evaluation and Improvement of Atmospheric Infrared Sounder (AIRS) Ice Cloud Retrievals. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1969.1/155521.
Council of Science Editors:
Firat VH. Evaluation and Improvement of Atmospheric Infrared Sounder (AIRS) Ice Cloud Retrievals. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155521
19.
Zhao, Ruike.
A Mechanics Study on Surface Ruga Morphologies of Soft
Materials.
Degree: PhD, Mechanics of Solids, 2016, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:674263/
► The surface morphologies of different soft material systems comprise various ruga phases (wrinkle, crease, fold or ridge). In the past a few decades, despite that…
(more)
▼ The surface morphologies of different soft material
systems comprise various ruga phases (wrinkle, crease, fold or
ridge). In the past a few decades, despite that one-
phase specific
studies have revealed certain intrinsic properties of some ruga
phases, their evolutions and transitions between each other are
still unclear. In this thesis, finite element analysis (FEA) is
used to study soft-material surface deformation of a homogeneous
half space, and one or multilayer thin film(s) on a substrate,
every component of which is represented by an incompressible
neo-Hookean solid. Furthermore, experiments are carried out by a
self-tightening loading device to verify the distinct morphologies.
Based on the simulation results, we construct the primary bilayer
(PB) ruga-
phase diagram which guides manipulation of various ruga
configurations in bilayer systems. On the PB ruga-
phase diagram,
various
phase boundaries represent bifurcation sites of ruga
structures caused by lateral compression of the bilayer. All the
ruga phases eventually evolve to a limit
phase of either global
crease or global fold localization, depending on the stiffness
ratio of the bilayer, when compressed up to the Biot critical
strain of 0.456. Moreover, the substrate pre-stretch promotes
ridging of bilayers and ruga mode-period multiplications during
loading. The ridging is intrinsically growth limited and highly
dependent on both substrate pre-stretch and modulus ratio of the PB
system. Configuration-mobility bifurcation of ridges, caused by
symmetry breaking of individual ridge configuration, leads to
order-disorder transition in the system. We pointed out two
irreversibility types for a bilayer system with a stiff film.
Irreversibility is typically exhibited through either mode locking
or primary period switching. The former leads to cyclic hysteresis
of ruga configurations during a loading/unloading cycle of the PB
system without strain mismatch. The latter exhibits snap jumps in
the PB ruga-
phase transitions, enhanced by substrate pre-stretch
and sufficient viscoelastic loss tangent. With multi-layered or
graded modulus structure, ridging can be suppressed, and hierarchal
wrinkle wavelengths can be observed during loading. Along this
line, we summarize the ruga morphology control aspects and
corresponding controlling factors.
Advisors/Committee Members: Kim, Kyung-suk (Director), Gao, Huajian (Reader), Franck, Christian (Reader).
Subjects/Keywords: ruga-phase diagram
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APA (6th Edition):
Zhao, R. (2016). A Mechanics Study on Surface Ruga Morphologies of Soft
Materials. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674263/
Chicago Manual of Style (16th Edition):
Zhao, Ruike. “A Mechanics Study on Surface Ruga Morphologies of Soft
Materials.” 2016. Doctoral Dissertation, Brown University. Accessed March 04, 2021.
https://repository.library.brown.edu/studio/item/bdr:674263/.
MLA Handbook (7th Edition):
Zhao, Ruike. “A Mechanics Study on Surface Ruga Morphologies of Soft
Materials.” 2016. Web. 04 Mar 2021.
Vancouver:
Zhao R. A Mechanics Study on Surface Ruga Morphologies of Soft
Materials. [Internet] [Doctoral dissertation]. Brown University; 2016. [cited 2021 Mar 04].
Available from: https://repository.library.brown.edu/studio/item/bdr:674263/.
Council of Science Editors:
Zhao R. A Mechanics Study on Surface Ruga Morphologies of Soft
Materials. [Doctoral Dissertation]. Brown University; 2016. Available from: https://repository.library.brown.edu/studio/item/bdr:674263/
20.
Hollen, Shawna M.
Cooper Pair Localization in Thin Films near the
Superconductor-Insulator Transition.
Degree: PhD, Physics, 2013, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:320462/
► The superconductor-insulator transition (SIT) is a well-known phenomenon that is observed in many types of superconducting systems, including elemental films and high Tc superconductors. Ultrathin…
(more)
▼ The superconductor-insulator transition (SIT) is a
well-known phenomenon that is observed in many types of
superconducting systems, including elemental films and high Tc
superconductors. Ultrathin films provide a versatile platform from
which to study this ubiquitous, and possibly universal, transition.
Two different theoretical approaches have been made to describe the
SIT in thin films. The first predicts that Cooper pairs (CPs) exist
in the insulating
phase, and the second proposes that the
transition is driven by pair-breaking, yielding an insulator of
localized single electrons.
Recent experiments showing the existence of an insulating
phase of localized CPs have provided significant support for the
first mechanism. This CP insulating (CPI)
phase exhibits dramatic
transport features including a giant magnetoresistance (MR) peak.
Previous work in the Valles lab found such a
phase in ultrathin
amorphous Bi films quench-condensed onto a substrate with a
nanohoneycomb (NHC) hole array. The local Cooper pairing
correlations of the CPI
phase were evident from Little-Parks-like
MR oscillations due to the hole array.
This thesis describes investigations of the mechanism for CP
localization and the emergence of the CPI
phase in NHC films. There
are three main results. First, the CPI
phase appears to be induced
in NHC films by the undulating surface of the substrate, which
produces regular spatial variations in thickness that give rise to
nanoscale CP islands. Second, the giant positive MR characteristic
of the CPI
phase emerges with increasing film thickness
simultaneously with the MR oscillation signal, associated with
local CP
phase coherence. The insulating phases of the thinnest
films and films in magnetic fields just beyond the MR peak likely
consist of CPs totally localized to their islands. Third, amorphous
holey films of uniform thickness do not exhibit a CPI
phase. These
films go from superconductors directly to fermionic insulators with
decreasing thickness. These results lend further insight to the
nature of the CPI
phase and also require at least two classes of
SITs: one that can describe the presence of a CPI
phase and one
that can describe a transition from a superconductor to a fermionic
insulator.
Advisors/Committee Members: Valles, James, Jr. (Director), Mitrovic, Vesna (Reader), Feldman, Dmitri (Reader).
Subjects/Keywords: quantum phase transition
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APA ·
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APA (6th Edition):
Hollen, S. M. (2013). Cooper Pair Localization in Thin Films near the
Superconductor-Insulator Transition. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:320462/
Chicago Manual of Style (16th Edition):
Hollen, Shawna M. “Cooper Pair Localization in Thin Films near the
Superconductor-Insulator Transition.” 2013. Doctoral Dissertation, Brown University. Accessed March 04, 2021.
https://repository.library.brown.edu/studio/item/bdr:320462/.
MLA Handbook (7th Edition):
Hollen, Shawna M. “Cooper Pair Localization in Thin Films near the
Superconductor-Insulator Transition.” 2013. Web. 04 Mar 2021.
Vancouver:
Hollen SM. Cooper Pair Localization in Thin Films near the
Superconductor-Insulator Transition. [Internet] [Doctoral dissertation]. Brown University; 2013. [cited 2021 Mar 04].
Available from: https://repository.library.brown.edu/studio/item/bdr:320462/.
Council of Science Editors:
Hollen SM. Cooper Pair Localization in Thin Films near the
Superconductor-Insulator Transition. [Doctoral Dissertation]. Brown University; 2013. Available from: https://repository.library.brown.edu/studio/item/bdr:320462/
21.
Liu, Yanan.
X-Ray Phase Contrast and Spatial Harmonic Imaging.
Degree: PhD, Chemistry, 2013, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:320524/
► The primary objective of research described in this dissertation was the development of an X-ray imaging technique to enhance normal X-ray phase contrast imaging. Phase…
(more)
▼ The primary objective of research described in this
dissertation was the development of an X-ray imaging technique to
enhance normal X-ray
phase contrast imaging.
Phase contrast imaging
exploits differences in the index of refraction of different
materials to image structures. The index of refraction difference
between an object and its surroundings causes a
phase shift between
the X-ray wave that travels through and outside the object. An
interference pattern results marking out the object. Liquid filled
liver images showed that liquid filled liver vessels provide clear
visualization. Additionally, a software processing method for
vessel detection was used to enhance the visibility of the
phase
contrast images. In this approach, 2-d Gabor wavelet and supervised
classification were used to detect vessel segmentation and classify
the vessels into a vessel class or a non-vessel class.
Furthermore,
phase contrast imaging combined with a
scattering technique called Spatial Harmonic Imaging (SHI) is
reported. Three important properties of spatial harmonic imaging
are shown in this dissertation. First, for objects containing
oriented structures, the scattering signal depends on the object’s
orientation relative to that of the grid, and the choice of
specific Fourier component. This property helps distinguish
different orientations that appear the same in absorption image.
Second, the image sensitivity can be increased by orders of
magnitude relative to normal X-ray
phase contrast imaging
technique. Third, spatial harmonic imaging enhances contrast at the
edge of an object by several times that of conventional
phase
contrast imaging. These properties substantially broaden the
applicability of
phase contrast imaging technique to clinical,
biological and industrial fields.
Advisors/Committee Members: Diebold, Gerald (Director), Rose-Petruck, Christoph (Director), Weber, Peter (Reader), Doll, Jimmie (Reader).
Subjects/Keywords: Phase contrast imaging
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Liu, Y. (2013). X-Ray Phase Contrast and Spatial Harmonic Imaging. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:320524/
Chicago Manual of Style (16th Edition):
Liu, Yanan. “X-Ray Phase Contrast and Spatial Harmonic Imaging.” 2013. Doctoral Dissertation, Brown University. Accessed March 04, 2021.
https://repository.library.brown.edu/studio/item/bdr:320524/.
MLA Handbook (7th Edition):
Liu, Yanan. “X-Ray Phase Contrast and Spatial Harmonic Imaging.” 2013. Web. 04 Mar 2021.
Vancouver:
Liu Y. X-Ray Phase Contrast and Spatial Harmonic Imaging. [Internet] [Doctoral dissertation]. Brown University; 2013. [cited 2021 Mar 04].
Available from: https://repository.library.brown.edu/studio/item/bdr:320524/.
Council of Science Editors:
Liu Y. X-Ray Phase Contrast and Spatial Harmonic Imaging. [Doctoral Dissertation]. Brown University; 2013. Available from: https://repository.library.brown.edu/studio/item/bdr:320524/
22.
Stephan, Baptiste.
Etude cinétique et microstructurale de la transformation ordre-désordre dans les alliages Ni2Cr à faible teneur en fer : A kinetic and microstructural study of order-disorder transformation in Ni2Cr alloys with low iron content.
Degree: Docteur es, Physique et Science des Matériaux, 2018, Université Lille I – Sciences et Technologies
URL: http://www.theses.fr/2018LIL1R004
► La mise en ordre (MEO) chimique des alliages Ni-Cr modifie leurs propriétés mécaniques et est une préoccupation potentielle pour leur utilisation dans les réacteurs à…
(more)
▼ La mise en ordre (MEO) chimique des alliages Ni-Cr modifie leurs propriétés mécaniques et est une préoccupation potentielle pour leur utilisation dans les réacteurs à eau sous pression. Dans ces travaux, la caractérisation de la cinétique de MEO par des vieillissements accélérés a été effectuée sur des alliages modèles à faible teneur en fer. L’apparition de la phase ordonnée Ni2Cr se traduit par une augmentation de la dureté. De plus, la mesure du pouvoir thermoélectrique s’est révélée très sensible à l’apparition de la MEO. Le rôle de la teneur en fer dans la cinétique du phénomène est négligeable à basse température (<450 °C), contrairement aux traitements thermiques pratiqués sur les alliages. Nous avons extrapolé nos résultats au cas des alliages industriels où la teneur en fer est plus élevée : le temps d’incubation de la MEO est estimé à 140 ans à 325 °C. La taille nanométrique des domaines ordonnés et leur faible différence de composition avec la matrice désordonnée rendent leur étude délicate. Nous avons utilisé des méthodes avancées de microscopie électronique en transmission pour progresser dans leur description. Grâce au couplage de l’analyse d’images et de cartographies d’orientation, la proportion surfacique des domaines ordonnés a pu être estimée sur un échantillon témoin. Des cartographies chimiques en perte d’énergie révèlent que le fer est en partie ségrégé autour des domaines ordonnés. Ceci remet en cause l’état d’ordre de la phase Ni2Cr, ce qui a été corroboré par des études quantitatives en microdiffraction sur des domaines ordonnés. A l’échelle atomique, les analyses montrent que le fer se substitue de préférence au chrome dans la maille ordonnée.
Chemical ordering in Ni-Cr alloys modifies their mechanical properties and is a potential issue for their use in pressurized water reactors. In this work, ordering kinetics have been determined by accelerated ageing on model alloys with low iron content. The Ni2Cr ordered phase appearance induces a hardness increase. Furthermore, thermoelectric power measurements have been revealed very sensitive to ordering. The iron content does not affect ordering kinetics at low temperatures (<450 °C), contrary to thermal treatments practiced on the alloys. Our results have been extrapolated to the industrial case, where the iron content is higher: ordering incubation time is estimated at 140 years at 325 °C. The nanometric size of ordered domains together with their small difference in chemical composition with the disordered matrix make their study difficult. We used advance characterizations with transmission electron microscopy to progress in their description. Thanks to the coupling of image analysis with orientation mappings, the surface proportion of ordered domains has been estimated on a control sample. Energy loss chemical maps reveal that the iron is partly segregated around ordered domains. This questions the state of order of the Ni2Cr phase, which is corroborated by quantitative microdiffractions achieved on ordered domains. At the atomic scale,…
Advisors/Committee Members: Jacob, Damien (thesis director), Delabrouille, Frédéric (thesis director).
Subjects/Keywords: Phase Ni2Cr; 669.94
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APA (6th Edition):
Stephan, B. (2018). Etude cinétique et microstructurale de la transformation ordre-désordre dans les alliages Ni2Cr à faible teneur en fer : A kinetic and microstructural study of order-disorder transformation in Ni2Cr alloys with low iron content. (Doctoral Dissertation). Université Lille I – Sciences et Technologies. Retrieved from http://www.theses.fr/2018LIL1R004
Chicago Manual of Style (16th Edition):
Stephan, Baptiste. “Etude cinétique et microstructurale de la transformation ordre-désordre dans les alliages Ni2Cr à faible teneur en fer : A kinetic and microstructural study of order-disorder transformation in Ni2Cr alloys with low iron content.” 2018. Doctoral Dissertation, Université Lille I – Sciences et Technologies. Accessed March 04, 2021.
http://www.theses.fr/2018LIL1R004.
MLA Handbook (7th Edition):
Stephan, Baptiste. “Etude cinétique et microstructurale de la transformation ordre-désordre dans les alliages Ni2Cr à faible teneur en fer : A kinetic and microstructural study of order-disorder transformation in Ni2Cr alloys with low iron content.” 2018. Web. 04 Mar 2021.
Vancouver:
Stephan B. Etude cinétique et microstructurale de la transformation ordre-désordre dans les alliages Ni2Cr à faible teneur en fer : A kinetic and microstructural study of order-disorder transformation in Ni2Cr alloys with low iron content. [Internet] [Doctoral dissertation]. Université Lille I – Sciences et Technologies; 2018. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2018LIL1R004.
Council of Science Editors:
Stephan B. Etude cinétique et microstructurale de la transformation ordre-désordre dans les alliages Ni2Cr à faible teneur en fer : A kinetic and microstructural study of order-disorder transformation in Ni2Cr alloys with low iron content. [Doctoral Dissertation]. Université Lille I – Sciences et Technologies; 2018. Available from: http://www.theses.fr/2018LIL1R004
23.
Viardin, Alexandre.
Modélisation par champ de phases de la croissance de la ferrite allotriomorphe dans les aciers Fe-C-Mn : Phase field modeling of allotriomorphic ferrite growth in Fe-C-Mn steels.
Degree: Docteur es, Science et ingénierie des matériaux et métallurgie, 2010, Lorraine INP
URL: http://www.theses.fr/2010INPL014N
► La ferrite allotriomorphe est une des morphologies de la ferrite dont la répartition spatiale influe fortement sur les propriétés mécaniques dans les aciers dual-phase. En…
(more)
▼ La ferrite allotriomorphe est une des morphologies de la ferrite dont la répartition spatiale influe fortement sur les propriétés mécaniques dans les aciers dual-phase. En fonction des traitements qu'ils subissent, la ferrite peut s'y répartir suivant les bandes de ségrégation en manganèse, issues de l'étape de solidification. Pour établir le rôle que joue le processus de croissance de la ferrite allotriomorphe sur la mise en place de la structure en bandes, nous avons développé un modèle de champ de phases possédant deux spécificités originales, imposées par le problème. D'une part, ce modèle est capable de reproduire les différents régimes cinétiques observés dans les alliages ternaires Fe-C-X, pilotés par la présence concomittante du carbone diffusant rapidement,et d'un élément substitutionnel X diffusant lentement. Nous avons ainsi mis en évidence la transition d'un régime initial rapide de paraéquilibre vers une croissance lente en orthoéquilibre, en bon accord avec des résultats expérimentaux de la littérature. D'autre part, notre modèle incorpore de manière économe la présence des joints de grains austénitiques, dont le rôle dans l'élimination des structures en bande est souligné par nos calculs. Nous observons ainsi qu'il existe un seuil d'intensité deségrégation en manganèse en dessous duquel le mouillage de la ferrite le long des joints de grain de plus grande énergie peut contrecarrer la croissance dans les bandes ségrégées négativement
The growth of allotriomorphic ferrite plays a major role in the formation of martensite bands in Dual-Phase steels. We have thus developed a phase field model to study the ferritic growth in different ternary Fe-C-X alloys, incorporating two necessary features. First, we have paid a particular attention to recover the different growth regimes due to the huge difference between the diffusion rates of Cand X substitutional species. Our calculations have exhibited a transition from fast paraequilibrium to slow orthoequilibrium in good agreement with experimental measurements in the literature. Second, austenite grain boundaries have been included in the model because they can conterbalance the manganese segregation bands, as shown in our calculations. Indeed, our results show that the bands can be broken bythe wetting of ferrite along the austenite grain boundaries, provided that the segregation is below a threshold value, and provided that the grain boundary energies are sufficiently high
Advisors/Committee Members: Gautier, Elisabeth (thesis director), Appolaire, Benoît (thesis director).
Subjects/Keywords: Champ de phase; Acier; Dual-phase; Ferrite; Phase field; Steel; Dual-phase; Ferrite
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APA (6th Edition):
Viardin, A. (2010). Modélisation par champ de phases de la croissance de la ferrite allotriomorphe dans les aciers Fe-C-Mn : Phase field modeling of allotriomorphic ferrite growth in Fe-C-Mn steels. (Doctoral Dissertation). Lorraine INP. Retrieved from http://www.theses.fr/2010INPL014N
Chicago Manual of Style (16th Edition):
Viardin, Alexandre. “Modélisation par champ de phases de la croissance de la ferrite allotriomorphe dans les aciers Fe-C-Mn : Phase field modeling of allotriomorphic ferrite growth in Fe-C-Mn steels.” 2010. Doctoral Dissertation, Lorraine INP. Accessed March 04, 2021.
http://www.theses.fr/2010INPL014N.
MLA Handbook (7th Edition):
Viardin, Alexandre. “Modélisation par champ de phases de la croissance de la ferrite allotriomorphe dans les aciers Fe-C-Mn : Phase field modeling of allotriomorphic ferrite growth in Fe-C-Mn steels.” 2010. Web. 04 Mar 2021.
Vancouver:
Viardin A. Modélisation par champ de phases de la croissance de la ferrite allotriomorphe dans les aciers Fe-C-Mn : Phase field modeling of allotriomorphic ferrite growth in Fe-C-Mn steels. [Internet] [Doctoral dissertation]. Lorraine INP; 2010. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2010INPL014N.
Council of Science Editors:
Viardin A. Modélisation par champ de phases de la croissance de la ferrite allotriomorphe dans les aciers Fe-C-Mn : Phase field modeling of allotriomorphic ferrite growth in Fe-C-Mn steels. [Doctoral Dissertation]. Lorraine INP; 2010. Available from: http://www.theses.fr/2010INPL014N
24.
Meziane, Rachid.
Structure, dynamique et transition de phases d'un cristal liquide smectique en milieu polymère : Structure, dynamique and phases transition of a smectic liquid crystal in polymer system.
Degree: Docteur es, Instrumentation et analyses avancées, 2008, Université Lille I – Sciences et Technologies
URL: http://www.theses.fr/2008LIL10141
► Le discernement du comportement du cristal liquide au sein d'une matrice rigide est d'une grande importance afin de rendre plus performant les composites de ce…
(more)
▼ Le discernement du comportement du cristal liquide au sein d'une matrice rigide est d'une grande importance afin de rendre plus performant les composites de ce type qui peuvent être intéressant pour leurs nombreuses applications notamment dans les vitrages électroactifs et les dispositifs d'affichages. La compréhension de sa réponse à un signal électrique ou à un effet thermique est primordiale. Le volume, dans lequel le cristal liquide se situe, contribue fortement à la qualité de cette réaction. Ce travail est une étude portant sur l'évolution structural de l'ensemble 4-cyano-4'-n-octyl-biphényl (8CB)/polystyrène depuis la phase homogène jusqu'à la phase cristalline du 8CB. L'analyse morphologique établit qu'une formation des objets selon le modèle d'Ostwald-Ripening soit à l'origine de la morphologie, on note également une forte dépendance de la concentration en mésogènes sur la dimension des domaines ségrégués. Ainsi, l'étude menée par calorimétrie indique que les plus petits domaines observés ont une taille suffisante pour engendrer des phases métastables du 8CB. On montre par spectroscopie infrarouge que les molécules de mésogène ne forment pas de liaisons p aromatiques avec le groupement phényle du polystyrène, cependant différents groupements chimiques des deux constituants sont en interaction. L'ordre smectique du cristal liquide est étudié par diffusion de neutrons aux petits angles. La structure smectique subit des déformations élastiques différentes selon les dimensions de confinements. En dernier lieu, nous discutons de l'influence du cristal liquide dans la polymérisation radicalaire. La cinétique de polymérisation est fortement perturbée dans des conditions riches en mésogène soulignant le caractère important du comportement du radical sur la polydispersité finale du polymère.
The understanding of the behavior of a low molecular weight liquid crystal within a rigid matrix is of great importance in order to make powerful composite materials of this type which can be interesting for many applications in particular in the display devices. The understanding of their response to an electric signal or a heating effect is of primary importance. The volume, in which the liquid crystal is located, strongly contributes to these effects. This work is a study relating to the structural evolution of the 4-cyano-4'-n-octyl-biphenyl (8CB)/polystyrene system from the homogeneous phase to the crystal line phase of the 8CB. The morphological analysis reveals that a formation of the objects according to the model of Ostwald-Ripening is at the origin of morphology, one also notes a strong dependence of the mesogene concentration on the segregated size domains. Thus, the study undertaken by calorimetry indicates that the smallest domains observed have a sufficient size to generate metastable phases of the 8CB. One shows by infra-red spectroscopy that the molecules of mesogene do not form aromatic p connections with the phenyl group of polystyrene, however various chemical groups of the two components are in interaction.…
Advisors/Committee Members: Maschke, Ulrich (thesis director).
Subjects/Keywords: Phase smectique; Polydispersité
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APA (6th Edition):
Meziane, R. (2008). Structure, dynamique et transition de phases d'un cristal liquide smectique en milieu polymère : Structure, dynamique and phases transition of a smectic liquid crystal in polymer system. (Doctoral Dissertation). Université Lille I – Sciences et Technologies. Retrieved from http://www.theses.fr/2008LIL10141
Chicago Manual of Style (16th Edition):
Meziane, Rachid. “Structure, dynamique et transition de phases d'un cristal liquide smectique en milieu polymère : Structure, dynamique and phases transition of a smectic liquid crystal in polymer system.” 2008. Doctoral Dissertation, Université Lille I – Sciences et Technologies. Accessed March 04, 2021.
http://www.theses.fr/2008LIL10141.
MLA Handbook (7th Edition):
Meziane, Rachid. “Structure, dynamique et transition de phases d'un cristal liquide smectique en milieu polymère : Structure, dynamique and phases transition of a smectic liquid crystal in polymer system.” 2008. Web. 04 Mar 2021.
Vancouver:
Meziane R. Structure, dynamique et transition de phases d'un cristal liquide smectique en milieu polymère : Structure, dynamique and phases transition of a smectic liquid crystal in polymer system. [Internet] [Doctoral dissertation]. Université Lille I – Sciences et Technologies; 2008. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2008LIL10141.
Council of Science Editors:
Meziane R. Structure, dynamique et transition de phases d'un cristal liquide smectique en milieu polymère : Structure, dynamique and phases transition of a smectic liquid crystal in polymer system. [Doctoral Dissertation]. Université Lille I – Sciences et Technologies; 2008. Available from: http://www.theses.fr/2008LIL10141
University of Toronto
25.
Sarkas, Ioannis.
Analysis and Design of W-Band Phase Shifters.
Degree: 2010, University of Toronto
URL: http://hdl.handle.net/1807/24637
► This thesis describes 80−94GHz and 70−77GHz interpolating phase shifters and the corresponding transmitter and receiver ICs, fabricated in 65-nm CMOS and SiGe BiCMOS technologies, respectively.…
(more)
▼ This thesis describes 80−94GHz and 70−77GHz interpolating phase shifters and the corresponding transmitter and receiver ICs, fabricated in 65-nm CMOS and SiGe BiCMOS technologies, respectively. Lumped inductors and transformers are employed to realize small-form factor 90 degree hybrids as needed in high density phased arrays. The CMOS transmitter exhibits absolute phase and amplitude errors of 4 degrees and 4dB, respectively, at 90GHz, when the phase is varied from 0 degrees to 360 degrees in steps of 22.5 degrees. The absolute phase error in the SiGe BiCMOS receiver is less than 5 degrees, with a maximum gain imbalance below 3dB at 74GHz. The peak gain
and power consumption are 3.8dB and 142mW from 1.2V supply for the CMOS transmitter, and 17dB and 128mW from 1.5V and 2.5V supplies for the SiGe BiCMOS receiver.
MAST
Advisors/Committee Members: Voinigescu, Sorin, Electrical and Computer Engineering.
Subjects/Keywords: phase shifters; 0544
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APA (6th Edition):
Sarkas, I. (2010). Analysis and Design of W-Band Phase Shifters. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/24637
Chicago Manual of Style (16th Edition):
Sarkas, Ioannis. “Analysis and Design of W-Band Phase Shifters.” 2010. Masters Thesis, University of Toronto. Accessed March 04, 2021.
http://hdl.handle.net/1807/24637.
MLA Handbook (7th Edition):
Sarkas, Ioannis. “Analysis and Design of W-Band Phase Shifters.” 2010. Web. 04 Mar 2021.
Vancouver:
Sarkas I. Analysis and Design of W-Band Phase Shifters. [Internet] [Masters thesis]. University of Toronto; 2010. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1807/24637.
Council of Science Editors:
Sarkas I. Analysis and Design of W-Band Phase Shifters. [Masters Thesis]. University of Toronto; 2010. Available from: http://hdl.handle.net/1807/24637
University of Debrecen
26.
Lukács, Béla.
Evaluation of my Final Teaching
.
Degree: DE – TEK – Bölcsészettudományi Kar, 2014, University of Debrecen
URL: http://hdl.handle.net/2437/178026
My thesis is on a rather special subject: my final teaching. By nature, it is a very personal topic, and the thesis written on it shows my pedagogical headway as an English teacher trainee.
Advisors/Committee Members: Gulyás, Anita (advisor).Subjects/Keywords: lesson plan;
phase
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APA (6th Edition):
Lukács, B. (2014). Evaluation of my Final Teaching
. (Thesis). University of Debrecen. Retrieved from http://hdl.handle.net/2437/178026
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):
Lukács, Béla. “Evaluation of my Final Teaching
.” 2014. Thesis, University of Debrecen. Accessed March 04, 2021.
http://hdl.handle.net/2437/178026.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lukács, Béla. “Evaluation of my Final Teaching
.” 2014. Web. 04 Mar 2021.
Vancouver:
Lukács B. Evaluation of my Final Teaching
. [Internet] [Thesis]. University of Debrecen; 2014. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/2437/178026.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lukács B. Evaluation of my Final Teaching
. [Thesis]. University of Debrecen; 2014. Available from: http://hdl.handle.net/2437/178026
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
27.
Sanchez-Hachair, Arnaud.
Solution de remédiation de terrains pollués aux "charrées de chrome" : élaboration d’une méthode d’électrocinétique couplée à la réduction chimique : Remediation of polluted soils with Chromite Ore Processing Residue (COPR) : Development of an method coupling electrokinetics and in-situ chemical reduction.
Degree: Docteur es, Géosciences, Ecologie, Paléontologie et Océanographie, 2018, Université Lille I – Sciences et Technologies
URL: http://www.theses.fr/2018LIL1R011
► Les charrées de chrome, résidus d’extraction du minerai de chrome (ou COPR), sont des matériaux de pH très basique (>10) composés de phases minérales cimentaires…
(more)
▼ Les charrées de chrome, résidus d’extraction du minerai de chrome (ou COPR), sont des matériaux de pH très basique (>10) composés de phases minérales cimentaires peu stables incorporant le chrome d’état d’oxydation +VI. La solution porale du matériau est chargée en Cr(VI) à des concentrations souvent supérieures à 100 mg/L. Les teneurs du matériau s’élèvent à 4-7 g Cr(VI)/kg. Le chrome VI est toxique. Par le passé, les charrées de chrome ont été utilisées en remblai d’infrastructures. C’est le cas d'une infrastructure dans le nord de la France. Notre étude a visé à développer une méthode de dépollution. Nous avons élaboré un couplage de la technique électrocinétique et d’une réduction chimique du Cr(VI). Nous apportons un réducteur qui migre à travers le matériau grâce à un champ électrique. Nous montrons que la réduction du chrome VI en chrome III précipité et moins toxique est possible avec une efficacité de 97 % et que les phases minérales ciment résistent à ce traitement. Nos travaux montrent que 60 à 70 % de la matière dans les charrées de chrome étudiées sont constitués de phases minérales amorphes. Elles sont sensibles aux variations de pH dans le milieu lors du traitement et réagissent en partie par dissolution, re-précipitation et transport. L’hydroxyde de Cr(III) formé lors du traitement est colloïdal et en partie mobiles. Des ajustements de la méthode sont possibles, en particulier le contrôle des variations de pH et la suppression de la mobilité indésirable du Cr(III). Les perspectives industrielles de cette méthode également adaptable à d’autres polluants rédox-sensibles, sont prometteuses.
Chromite Ore Processing Residues (COPR) are materials with strongly alcaline pH (>10) containing fairly soluble cement phases bearing hexavalent chromium as a substituted anion. The pore water contains high concentrations of mobile Cr(VI) often above 100 mg/L. The bulk concentration of Cr(VI) is 4 - 7 g /kg COPR. Hexavalent chromium is a toxic compound. Historically, COPR was used for embankments and backfills in construction works. This was the case for an infrastructure in the north of France. In this study we aimed to develop a remediation method suitable for treatment of this backfills in-situ. We coupled the electrokinetics technique with in situ chemical reduction of Cr(VI). In this method, the added reductive compound migrates through the material under the effect of an electric field. We show that Cr(VI) reduction to the less toxic Cr(III) is possible with as high as 97% efficiency. Results show that the crystallized mineral phases are not impacted by the treatment. However, 60 to 70% of the mineral phases are amorphous as quantification studies show. The pH change during treatment fragilizes them, resulting in some dissolution, reprecipitation, electromigration and electrophoretic transport phenomena. Cr(III)-hydroxide, produced during the treatment, also appear to be in a mobile colloidal form. Optimisations of the technique are possible, in particular the control of pH changes and the suppression of…
Advisors/Committee Members: Hofmann, Annette (thesis director), Potdevin, Jean-Luc (thesis director).
Subjects/Keywords: Phase cimentaire; 628.55
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APA (6th Edition):
Sanchez-Hachair, A. (2018). Solution de remédiation de terrains pollués aux "charrées de chrome" : élaboration d’une méthode d’électrocinétique couplée à la réduction chimique : Remediation of polluted soils with Chromite Ore Processing Residue (COPR) : Development of an method coupling electrokinetics and in-situ chemical reduction. (Doctoral Dissertation). Université Lille I – Sciences et Technologies. Retrieved from http://www.theses.fr/2018LIL1R011
Chicago Manual of Style (16th Edition):
Sanchez-Hachair, Arnaud. “Solution de remédiation de terrains pollués aux "charrées de chrome" : élaboration d’une méthode d’électrocinétique couplée à la réduction chimique : Remediation of polluted soils with Chromite Ore Processing Residue (COPR) : Development of an method coupling electrokinetics and in-situ chemical reduction.” 2018. Doctoral Dissertation, Université Lille I – Sciences et Technologies. Accessed March 04, 2021.
http://www.theses.fr/2018LIL1R011.
MLA Handbook (7th Edition):
Sanchez-Hachair, Arnaud. “Solution de remédiation de terrains pollués aux "charrées de chrome" : élaboration d’une méthode d’électrocinétique couplée à la réduction chimique : Remediation of polluted soils with Chromite Ore Processing Residue (COPR) : Development of an method coupling electrokinetics and in-situ chemical reduction.” 2018. Web. 04 Mar 2021.
Vancouver:
Sanchez-Hachair A. Solution de remédiation de terrains pollués aux "charrées de chrome" : élaboration d’une méthode d’électrocinétique couplée à la réduction chimique : Remediation of polluted soils with Chromite Ore Processing Residue (COPR) : Development of an method coupling electrokinetics and in-situ chemical reduction. [Internet] [Doctoral dissertation]. Université Lille I – Sciences et Technologies; 2018. [cited 2021 Mar 04].
Available from: http://www.theses.fr/2018LIL1R011.
Council of Science Editors:
Sanchez-Hachair A. Solution de remédiation de terrains pollués aux "charrées de chrome" : élaboration d’une méthode d’électrocinétique couplée à la réduction chimique : Remediation of polluted soils with Chromite Ore Processing Residue (COPR) : Development of an method coupling electrokinetics and in-situ chemical reduction. [Doctoral Dissertation]. Université Lille I – Sciences et Technologies; 2018. Available from: http://www.theses.fr/2018LIL1R011
University of Connecticut
28.
Badran, Karim M.
Theoretical Formulation of Phase Field Fracture.
Degree: MS, Mechanical Engineering, 2014, University of Connecticut
URL: https://opencommons.uconn.edu/gs_theses/708
► Phase field theory provides a new and different method of modeling crack propagation. This method utilizes a mathematical model to deal with interfaces of…
(more)
▼ Phase field theory provides a new and different method of modeling crack propagation. This method utilizes a mathematical model to deal with interfaces of multiphase problems. Although it is often used for solidification, in this project it will be used to model fracture dynamics. Which is done by considering a crack and an undamaged material as two separate phases and the crack progress through diffusion. This approach offers a computationally effective approach to model crack propagation, and allows for smooth transition between interfaces. The objective of this project was to test a theoretical
phase diffusion model developed by B. N. Cassenti et al.[1] for crack propagation. This was done using a MATLAB code written by Nicholas W. Oren that utilizes finite difference method. A number of tests cases were done to examine the behavior of the governing equations. Test cases consisted of a crack on a plate undergoing tension or shear stress on the boundaries of the plate. Through the test cases the physical dependency of the
phase on the random local velocity was studied. In addition the effects of a double-well potential term and an elastic modulus factor on crack growth were also examined. A novel method of tracking the crack front and a test case for crack arrest were presented. The development of a physics based diffusion model will also be discussed.
Advisors/Committee Members: Dr. Eric Jordan, Dr. Alexander Staroselsky, Dr. Brice N. Cassenti.
Subjects/Keywords: Phase Field Fracture
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APA (6th Edition):
Badran, K. M. (2014). Theoretical Formulation of Phase Field Fracture. (Masters Thesis). University of Connecticut. Retrieved from https://opencommons.uconn.edu/gs_theses/708
Chicago Manual of Style (16th Edition):
Badran, Karim M. “Theoretical Formulation of Phase Field Fracture.” 2014. Masters Thesis, University of Connecticut. Accessed March 04, 2021.
https://opencommons.uconn.edu/gs_theses/708.
MLA Handbook (7th Edition):
Badran, Karim M. “Theoretical Formulation of Phase Field Fracture.” 2014. Web. 04 Mar 2021.
Vancouver:
Badran KM. Theoretical Formulation of Phase Field Fracture. [Internet] [Masters thesis]. University of Connecticut; 2014. [cited 2021 Mar 04].
Available from: https://opencommons.uconn.edu/gs_theses/708.
Council of Science Editors:
Badran KM. Theoretical Formulation of Phase Field Fracture. [Masters Thesis]. University of Connecticut; 2014. Available from: https://opencommons.uconn.edu/gs_theses/708
University of Illinois – Chicago
29.
Danciu, Oana.
Phase I Study of Procaspase Activating Compound-1 (PAC-1) in the Treatment of Advanced Malignancies.
Degree: 2018, University of Illinois – Chicago
URL: http://hdl.handle.net/10027/22612
► The primary objective of this study was to determine the maximum tolerated dose (MTD) of first procaspase-activating compound (PAC-1) in patients with advanced malignancy by…
(more)
▼ The primary objective of this study was to determine the maximum tolerated dose (MTD) of first procaspase-activating compound (PAC-1) in patients with advanced malignancy by evaluation of toxicity and tolerability. The MTD of PAC-1 was determined using a modified-Fibonacci dose-escalation 3+3 design, with a total of five dose levels. PAC-1 was given at the assigned dose orally on days 1-21 of a 28 day cycle. Disease reassessment was done every 2 cycles (8 weeks). Treatment for patients in the trial continued until disease progression, unacceptable toxicity, or patient refusal. For all dose cohorts, pharmacokinetics of PAC-1 were assessed following doses administered on days 1 and 21 of the first cycle. Twenty one patients were enrolled. All 21 patients received at least 1 dose of study drug and 15 were evaluable for at least 2 cycles; 6 patients were not evaluable, including 1 who dropped out after beginning therapy for reasons other than adverse events (AEs), and 5 who had rapidly progressive disease that precluded completion of 2 full cycles of therapy. Dose was escalated from dose level 1 (75 mg daily) to dose level 5 (450 mg daily). Three patients at each dose level 1-5 received at least 2 dosing cycles and no dose-limiting toxicities (DLTs) were observed. The majority of serious adverse events were grade 2 and 3 with the most common being constipation, electrolytes abnormalities, and infections. All serious adverse events (SAEs) were determined to be unrelated or unlikely related to the study drug. One patient expired while on study due to progression of disease. Review of the neurologic exams and Mini-Mental State Examination (MMSE) test scores from time points yoked with the neurocognitive (NCF) testing showed a consistent pattern of stable neurologic exams and MMSE scores. The pharmacokinetic data supports the satisfactory systemic delivery of PAC-1 following oral administration and acceptable absorption and elimination profiles.
Advisors/Committee Members: Dudek, Arkadius (advisor), Emmadi, Raj (committee member), Zwanziger, Jack (chair).
Subjects/Keywords: phase I; tumor
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APA (6th Edition):
Danciu, O. (2018). Phase I Study of Procaspase Activating Compound-1 (PAC-1) in the Treatment of Advanced Malignancies. (Thesis). University of Illinois – Chicago. Retrieved from http://hdl.handle.net/10027/22612
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):
Danciu, Oana. “Phase I Study of Procaspase Activating Compound-1 (PAC-1) in the Treatment of Advanced Malignancies.” 2018. Thesis, University of Illinois – Chicago. Accessed March 04, 2021.
http://hdl.handle.net/10027/22612.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Danciu, Oana. “Phase I Study of Procaspase Activating Compound-1 (PAC-1) in the Treatment of Advanced Malignancies.” 2018. Web. 04 Mar 2021.
Vancouver:
Danciu O. Phase I Study of Procaspase Activating Compound-1 (PAC-1) in the Treatment of Advanced Malignancies. [Internet] [Thesis]. University of Illinois – Chicago; 2018. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/10027/22612.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Danciu O. Phase I Study of Procaspase Activating Compound-1 (PAC-1) in the Treatment of Advanced Malignancies. [Thesis]. University of Illinois – Chicago; 2018. Available from: http://hdl.handle.net/10027/22612
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Manchester
30.
Ward, Joseph.
MAX phase ceramics for nuclear applications.
Degree: PhD, 2018, University of Manchester
URL: https://www.research.manchester.ac.uk/portal/en/theses/max-phase-ceramics-for-nuclear-applications(b6b22354-f430-4e78-824e-3e34afd83273).html
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.756886
► The PhD research presented here is part of the new nuclear manufacturing (NNUMAN) research group, looking into novel materials and manufacturing processes. NNUMAN is an…
(more)
▼ The PhD research presented here is part of the new nuclear manufacturing (NNUMAN) research group, looking into novel materials and manufacturing processes. NNUMAN is an EPSRC funded (EP/J021172/1) program with direct support from Rolls Royce plc. The fabrication of MAX phase coatings by different means and assessing their tribological properties was the original theme of this thesis. However, due to issues with fabrication processes the overriding direction was moved towards assessing the response of bulk MAX phases to irradiating and corrosive environments. It is believed that this research will contribute to the understanding of suitable compositions and applications within nuclear. The MAX phases comprise an early transition metal (M), an A-group element (A) and either carbon or nitrogen (X). They have an inherently nano-layered structure with alternating ceramic (MX) and metallic (A) layers. The unique mix of both ceramic and metallic properties have made MAX phases a proposed material for nuclear applications. Proton irradiation is performed on Ti3SiC2, Ti3AlC2, Ti2AlC and Cr2AlC bulk MAX phases to 0.1 dpa at 350 °C. Crystallographic instabilities are observed through x-ray diffraction (XRD) analysis after irradiation. A mechanism for irradiation induced point defect swelling is proposed, by matching XRD and modelling data. Anti-site point defects are proposed to be a major contributor to anisotropic lattice parameter changes in Ti3SiC2. Additional carbon interstitial defects are also proposed in Ti3AlC2, as well as anti-site defects, making them less radiation tolerant. Further proton irradiations on Ti3SiC2 and Ti3AlC2 were performed at elevated temperatures to propose a temperature at which lattice changes are not observed. It is concluded that high proton fluences require temperatures in excess of ~700 °C and ~1,000 °C for Ti3SiC2 and Ti3AlC2, respectively. Corrosion of bulk MAX phases in simulated primary water also suggests a deleterious response to normal light water reactor (LWR) operations. Advanced scanning transmission electron microscopy (STEM) techniques, such as energy dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS), is employed to understand corrosion mechanisms. Selective oxidation of A-layers is observed, with no evidence of passivation for Ti3SiC2, Ti3AlC2 and Ti2AlC. The response of Cr2AlC was most promising as little oxidation occurred, which is confirmed also with XRD analysis. A comprehensive corrosion mechanism is proposed, whereby compositions of MAX phase in LWR coolants is limited.
Subjects/Keywords: 620; MAX phase
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Record Details
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Cite
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ward, J. (2018). MAX phase ceramics for nuclear applications. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/max-phase-ceramics-for-nuclear-applications(b6b22354-f430-4e78-824e-3e34afd83273).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.756886
Chicago Manual of Style (16th Edition):
Ward, Joseph. “MAX phase ceramics for nuclear applications.” 2018. Doctoral Dissertation, University of Manchester. Accessed March 04, 2021.
https://www.research.manchester.ac.uk/portal/en/theses/max-phase-ceramics-for-nuclear-applications(b6b22354-f430-4e78-824e-3e34afd83273).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.756886.
MLA Handbook (7th Edition):
Ward, Joseph. “MAX phase ceramics for nuclear applications.” 2018. Web. 04 Mar 2021.
Vancouver:
Ward J. MAX phase ceramics for nuclear applications. [Internet] [Doctoral dissertation]. University of Manchester; 2018. [cited 2021 Mar 04].
Available from: https://www.research.manchester.ac.uk/portal/en/theses/max-phase-ceramics-for-nuclear-applications(b6b22354-f430-4e78-824e-3e34afd83273).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.756886.
Council of Science Editors:
Ward J. MAX phase ceramics for nuclear applications. [Doctoral Dissertation]. University of Manchester; 2018. Available from: https://www.research.manchester.ac.uk/portal/en/theses/max-phase-ceramics-for-nuclear-applications(b6b22354-f430-4e78-824e-3e34afd83273).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.756886
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Open Access Theses and Dissertations