Dissertation (Ph.D.)--Auburn University, 2009. / Abstract. Includes bibliographic references.

New materials always have the possibility of revolutionizing manufacturing processes and the way we live. Bronze, steel alloys, vulcanized rubber, ceramics, and fiber optic cables are just of few of the materials man has discovered which improved his quality of life. One of the more recent additions to the field of material science are materials that exhibit what is known as the shape memory effect. Both metals and synthetic polymers can acquire this property through processing and chemistry. However while shape memory polymers hold a lot of promise, it will require more research and development to make them affordable and useful in large scale applications. / text

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 144-158). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 123-127). Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 249-257).

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Zirconia based ceramics are strong, hard, inert, and smooth, with low thermal conductivity and good biocompatibility. Such properties made zirconia ceramics an ideal material for different applications form thermal barrier coatings (TBCs) to biomedicine applications like femoral implants and dental bridges. However, this unusual versatility of excellent properties would be mediated by the metastable tetragonal (or cubic) transformation to the stable monoclinic phase after a certain exposure at service temperatures. This transformation from tetragonal to monoclinic, known as LTD (low temperature degradation) in biomedical application, proceeds by propagation of martensite, which corresponds to transformation twinning. As such, tetragonal to monoclinic transformation is highly sensitive to mechanical and chemomechanical stresses. It is known in fact that this transformation is the source of the fracture toughening in stabilized zirconia as it occurs at the stress concentration regions ahead of the crack tip. This dissertation is an attempt to provide a kinetic-based model for tetragonal to monoclinic transformation in zirconia. We used the phase field technique to capture the temporal and spatial evolution of monoclinic phase. In addition to morphological patterns, we were able to calculate the developed internal stresses during tetragonal to monoclinic transformation. The model was started form the two dimensional single crystal then was expanded to the two dimensional polycrystalline and finally to the three dimensional single crystal. The model is able to predict the most physical properties associated with tetragonal to monoclinic transformation in zirconia including: morphological patterns, transformation toughening, shape memory effect, pseudoelasticity, surface uplift, and variants impingement. The model was benched marked with several experimental works. The good agreements between simulation results and experimental data, make the model a reliable tool for predicting tetragonal to monoclinic transformation in the cases we lack experimental observations.

by Lau Kwok Kin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 82-87). / Abstracts in English and Chinese. / List of Figures --- p.vi / List of Tables --- p.vii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Objective of This Thesis --- p.3 / Chapter 1.2 --- Organization of This Thesis --- p.3 / Chapter 2 --- Literature Review --- p.4 / Chapter 2.1 --- Facial Memory Recall --- p.4 / Chapter 2.2 --- Facial Recognition --- p.6 / Chapter 2.2.1 --- Earlier Approaches --- p.7 / Chapter 2.2.2 --- Feature and Template Matching --- p.8 / Chapter 2.2.3 --- Neural Network --- p.10 / Chapter 2.2.4 --- Statistical Approach --- p.14 / Chapter 3 --- A Forensic Application of Facial Recall --- p.19 / Chapter 3.1 --- Motivation --- p.20 / Chapter 3.2 --- AICAMS-FIT --- p.20 / Chapter 3.2.1 --- The Facial Component Library --- p.21 / Chapter 3.2.2 --- The Feature Selection Module --- p.24 / Chapter 3.2.3 --- The Facial Construction Module --- p.24 / Chapter 3.3 --- The Interaction Between The Three Main Components --- p.29 / Chapter 3.4 --- Summary --- p.30 / Chapter 4 --- Sketch-to-Sketch Matching --- p.31 / Chapter 4.1 --- The Representation of A Composite Face --- p.31 / Chapter 4.2 --- The Component-based Encoding Scheme --- p.32 / Chapter 4.2.1 --- Local Feature Analysis --- p.34 / Chapter 4.2.2 --- Similarity Matrix --- p.36 / Chapter 4.3 --- Experimental Results and Evaluation --- p.41 / Chapter 4.4 --- Shortcomings of the encoding scheme --- p.44 / Chapter 4.4.1 --- Size Variation --- p.45 / Chapter 4.5 --- Summary --- p.51 / Chapter 5 --- Sketch-to-Photo/Photo-to-Sketch Matching --- p.52 / Chapter 5.1 --- Principal Component Analysis --- p.53 / Chapter 5.2 --- Experimental Setup --- p.56 / Chapter 5.3 --- Experimental Results --- p.59 / Chapter 5.3.1 --- Sketch-to-Photo Matching --- p.59 / Chapter 5.3.2 --- Photo-to-Sketch Matching --- p.62 / Chapter 5.4 --- Summary --- p.66 / Chapter 6 --- Future Work --- p.67 / Chapter 7 --- Conclusions --- p.70 / Chapter A --- Image Library I --- p.72 / Chapter A.1 --- The Database for Searching --- p.72 / Chapter A.2 --- The Database for Testing --- p.74 / Chapter B --- Image Library II --- p.75 / Chapter B.1 --- The Photographic Database --- p.75 / Chapter B.2 --- The Sketch Database --- p.77 / Chapter C --- The Eigenfaces --- p.78 / Chapter C.1 --- Eigenfaces of Photographic Database (N = 20) --- p.78 / Chapter C.2 --- Eigenfaces of Photographic Database (N = 100) --- p.79 / Chapter C.3 --- The Eigenfaces of Sketch Database --- p.81 / Bibliography --- p.82

RESUME Les alliages Cu-Al-Ni sont les seuls à posséder une température de transformation allant jusque 200°C. Ceci leur confère un avantage par rapport aux alliages Cu-Al-Zn ou Ti-Ni dont les températures de transformation ne dépassent pas 100°C. Néanmoins, un chauffage temporaire au dessus de 200°C peut provoquer une perte de l’effet mémoire des alliages Cu-Al-Ni. Nous avons étudié trois alliages aves des teneurs en nickel comprises entre 3 % et 5 %. L’objectif de notre étude est double : • Étudier la cinétique des transformations structurales au cours d’un vieillissement en phase β dans le domaine de températures 200°C-350°C ; • Quantifier la perte de l’effet mémoire au cours du vieillissement afin de déterminer les possibilités d’utilisation de ces alliages au dessus de 200°C. La caractérisation structurale a été effectuée par microscope optique, diffraction des rayons X, microscopie électronique à balayage et microscopie électronique en transmission. Les caractéristiques de la transformation martensitique ont été déterminées par analyse thermomécanique (TMA), par calorimétrie différentielle à balayage (DSC) et par des mesures de résistivité électrique. La perte de l’effet mémoire simple sens a été quantifiée à partir des courbes de transformations obtenues par analyse thermomécanique(TMA) sur des échantillons comprimés. Les résultats principaux sont :  Au dessus de 300°C, la précipitation de la phase d’équilibre у₂ se produit au cours du vieillissement. Elle entraîne une augmentation de la température Mѕ. Nous avons montré que cette augmentation de Ms peut être reliée à la fraction transformée par une loi de puissance.  Il n’y a pas de relation directe, en revanche, entre la perte de l’effet mémoire et la fraction transformée. Cela indique que le nombre et la taille des précipités ont une influence sur la perte de l’effet mémoire.  Pour un vieillissement de 256 minutes à 275°C, la perte de l’effet mémoire est inférieure à 15%. Par contre, au dessus de 300°C, la perte de l’effet mémoire est très rapide. Nous pouvons donc considérer que 275°C est une température limite à ne pas dépasser pour ces alliages. ABSTRACT The shape memory alloys Cu-Al-Ni are the only ones to have a transformation temperature of up to 200°C. This gives them an advantage compared to shape memory alloys Cu-Zn-Al or Ti-Ni whose transformation temperatures do not exceed 100 ° C. However, a temporary heating above 200 ° C can cause a loss of memory effect alloys Cu-Al-Ni. We studied three alloys with nickel content between 3% and 5%. The aim of our study is twofold: • Studying the kinetics of structural changes during aging in β phase in the temperature range 200 °C-350 °C. • Quantifying the loss of memory effect with aging in order to determine the potential use of these alloys above 200°C. The structural characterization was carried out by optical microscope, XR-ray diffraction, scanning electron microscopy and transmission electron microscopy. The characteristics of the martensitic transformation were determined by thermomechanical analysis (TMA), differential scanning calorimetry (DSC) and by measuring the electrical resistivity. The loss of one way shape memory was quantified from the curves obtained by thermomechanical analysis (TMA) on compressed samples. The main results are:  Above 300 ° C, the precipitation of equilibrium phase γ2 occurs during aging. It causes an increase in temperature Mѕ. We showed that this increase of Ms may be related to the fraction transformed by a power law.  There is no direct relationship between the loss of memory effect and the fraction transformed. This indicates that the number and size of the precipitates have an influence on the loss of memory effect.  For 256 minutes of aging at 275°C, loss of memory effect is less than 15%. On the other hand, above 300 ° C, loss of memory effect is very fast. We can therefore consider that 275°C is the temperature limit that not may be exceeded for these alloys.