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In the past 15 years, a large amount of public-domain lidar data has been collected over the Southeastern United States. Most of these acquisitions were undertaken by government agencies, primarily for non-forestry purposes. That is, they were collected mostly to aid in the creation of digital terrain models and to support hydrological and engineering assessments. Such data is not ideal for forestry purposes mainly due to the low pulse density per square meter, the high scan angles and low swath overlaps associated with these acquisitions. Nevertheless, the large area of coverage involved motivated this work. In this dissertation, I first look at how such lidar data (from non-forestry acquisitions) can be combined with National Forest Inventory tree height data to generate a large-area canopy height model. A simple linear regression model was developed using two lidar-based metrics as predictors: the 85th percentile of heights of canopy first returns and the coefficient of variation of the heights of canopy first returns. This model had good predictive ability over 76 disparate lidar projects, covering an area of approximately 297,000 square kilometers between them. Factors leading to the residual lack-of-fit of the model were also analyzed and quantified. For example, predictive ability was found to be better for softwood forests, forests with more homogeneous vegetation structure and for terrains with gentler slopes. Given that as much as 30% of the US is covered by public domain non-forestry lidar acquisitions, this is a first step for constructing a national wall-to-wall vertical vegetation structure map, which can then be used to ask important questions regarding forest inventories, carbon sequestration, wildlife habitat suitability and fire risk mitigation. Then, I examined whether such lidar data could be further used to predict understory shrub presence over disparate forest types. The predictability of classification model was low (accuracy = 62%, kappa = 0.23). Canopy occlusion factors and the heterogeneity of the understory layer were implicated as the main reasons for this poor performance. An analysis of the metrics chosen by the modeling framework highlighted the importance of non-understory metrics (metrics related to canopy openness and topographic aspect) in influencing shrub presence. As the proposed set of metrics were developed over a wide range of temperate forest types and topographic conditions of Southeastern US, it is expected that it will be useful for more localized future studies. Lastly, I explored the possibility of combining lidar-derived canopy height maps with Landsat-derived stand-age maps to predict plantation pine site index over large areas (site index is a measure of forest productivity). The model performance was assessed using a Monte Carlo technique (RMSE = 3.8 meters, relative RMSE = 19%). A sample site index map for large areas of Virginia and South Carolina was generated (map coverage area: 832 sq. km) and implications were discussed. Analysis of the resulting map revealed the following: (1) there is an increase in site index in most areas, compared to the 1970s, and (2) approximately 83% of the area surveyed had low levels of productivity (defined as site index < 22.0 meters for base age of 25 years). This work highlights the efficacy of combining lidar-based canopy height maps with other similar remote sensing based datasets to understand aspects of forest productivity over large areas, and to help make policy-relevant recommendations. / Ph. D.

La cristallisation assistée par ultrasons permet de diminuer le temps d'induction et la largeur de la zone métastable, de modifier la distribution de tailles, de modifier le faciès des cristaux et d'augmenter le nombre des cristaux formés. L'origine microscopique de cet effet reste à ce jour non élucidée. Les ultrasons de puissance engendrent dans un liquide la naissance et l'oscillation très violente de milliards de petites bulles de gaz, phénomène appelé cavitation. Le cycle d'une de ces bulles sur une période acoustique consiste en une phase explosive suivie d'une implosion violente. A la fin de l'implosion, la pression peut atteindre 1 GPa. Plusieurs hypothèses sur les mécanismes mis en jeu sont proposées dans la littérature : refroidissement de la solution et augmentation de la pression au voisinage de l'interface, évaporation du solvant dans la bulle, et ségrégation des molécules ou des ions du soluté au voisinage de la bulle lors de la phase implosive. Afin d'examiner l'influence de la pression, des expériences de cristallisation du sulfate de zinc heptahydraté ont été menées (mesure de temps d'induction). Ce sel présente une solubilité indépendante de la pression entre 0 et 10 000 bars. Nos expériences ont montré que le temps d'induction est fortement diminué en présence d'ultrasons. Ce résultat nous permet d'affirmer que la pression au voisinage de la bulle n'entre pas en jeu dans le mécanisme de la nucléation primaire du ZnSO4,7H2O en présence d'ultrasons. Après l'étude de l'effet de la sursaturation, nous avons essayé d'exploré l'effet de la puissance ultrasonore, du gaz dissous et de la hauteur du liquide dans la cuve sur le temps d'induction. Il a été constaté que les ultrasons permettent de diminuer le temps d'induction. Il a été observé que la courbe du temps d'induction en fonction de la hauteur de la solution présente un minimum. Un autre volet de cette thèse réservé à la modélisation et la simulation. Dans un premier temps, la concentration en clusters ou agrégats moléculaires au voisinage de la bulle été calculée dans le cas du ZnSO4,7H2O grâce à la théorie de la ségrégation en fonction de la pression acoustique. La simulation montre qu'il y a une sur-concentration des clusters (jusqu'à 25 fois supérieure à la concentration stationnaire) augmentant ainsi la probabilité de contact des clusters, durant un temps très court, pouvant ainsi modifier le processus global de nucléation. Dans un deuxième temps, la modélisation/simulation de l'acoustique par COMSOL est réalisée en vue de déterminer les résonances de notre système (liquide + parois de la cuve). Les résonances observées sont cohérentes avec les mesures de temps d'induction. / Power ultrasound is known to enhance crystals nucleation, and nucleation times can be reduced by oneup to three orders of magnitude for several organic or inorganic crystals. The precise physics involved in this phenomenon still remains unclear, and various mechanisms involving the action of inertial cavitation bubbles have been proposed. In this paper, two of these mechanisms, pressure and ségrégation effects, are examined. The first one concerns the variations of supersaturation induced by the high pressures appearing in the neighbourhood of a collapsing bubble, and the second one results from the modification of clusters distribution in the vicinity of bubble. Crystallisation experiments were performed on zinc sulphate heptahydrate ZnSO4. 7H2O, which has been chosen for its pressure-independent solubility, so that pressure variations have no effect on supersaturation. As observed in past studies on other species, induction times were found lower under insonification than under silent conditions at low supersaturations, which casts some doubts on a pure pressure effect. The interfacial energy between the solid and the solution was estimated from induction times obtained in silent conditions, and, using classical nucléation theory, the steady-state distribution of the clusters was calculated. Segregation theory was then applied to calculate the over-concentrations of n-sized clusters at the end of the collapse of a 4 lmbubble driven at 20 kHz by different acoustic pressures. The over-concentration of clusters close to the critical size near a collapsing bubble was found to reach more than one order of magnitude, which may favour the direct attachment process between such clusters, and enhance the global nucleation kinetics. The effects of acoustic cavitation on crystallization of ZnSO4. 7H2O was observed in a sono-reactor build-up from a large emitting area transducer located at the bottom of the vessel. The experimental results have shown that the dissipated acoustic power passes through a maximum at about 15±1 cm, and that the induction-time passes through a minimum for the same liquid-level. The dissipated-power and the induction-time are found to be well correlated as the liquid height was varied. The acoustics of the sono-reactor was studied with linear acoustics, accounting for the wall vibrations by using the COMSOL software. Theoretical dissipated acoustic powers were compared to the experimental ones.

O objetivo desta dissertação é apresentar uma leitura de O Morro dos Ventos Uivantes (1847), de Emily Brontë, e de Jane Eyre (1847), de Charlotte Brontë, com foco nas convenções góticas contidas nas duas obras e observando as maneiras como tais convenções interferem nos movimentos das duas protagonistas, Catherine e Jane, cada uma lutando para se adaptar ao seu espaço e, ao mesmo tempo, para realizar seus anseios. Apesar de as duas obras serem estruturalmente diferentes uma da outra, ambas compartilham uma atmosfera gótica intensa, bem como uma consequente densidade psicológica que influencia a disposição mental das duas protagonistas. A leitura dos dois romances foi conduzida com a finalidade de explorar as relações encontradas entre os aspectos estruturais, sociais e psicológicos envolvidos, ressaltando os elementos góticos que representam os desafios que Catherine e Jane são forçadas a enfrentar. A obra The Coherence of Gothic Conventions (1986), da crítica literária Eve Kosofsky Sedgwick, é utilizada para identificar e contextualizar a capacidade que as imagens góticas têm de traduzir o peso imposto pelas convenções sociais sobre o processo natural de crescimento das duas protagonistas. Considerando que esse peso é consideravelmente ampliado pelas práticas sociais ligadas a questões de gênero, foi explorado o conceito de Gótico Feminino, como apresentado pela Professora Carol Margaret Davison. Especial atenção é reservada para as imagens relacionadas com espaço – o espaço psicológico necessário para o crescimento emocional das protagonistas; e o espaço físico, que determina onde e como elas devem se movimentar. Aqui o suporte teórico é oferecido pelas poéticas dos elementos primitivos, de Gaston Bachelard, para análise do corpo de imagens apresentadas nos dois romances. A conclusão comenta as soluções encontradas por Catherine Earnshaw e Jane Eyre para abrir caminho e superar os obstáculos que se lhes apresentam; e também ressalta o quanto as convenções góticas conseguem revelar sobre a estrutura social que elas representam. / This thesis consists of a reading of Emily Brontë‘s Wuthering Heights (1847) and Charlotte Brontë‘s, Jane Eyre (1847), focusing on the body of Gothic conventions they hold, and the ways in which such conventions interfere with the movements of the two female protagonists, Catherine and Jane, each struggling to fit into their space, while trying to accomplish their desires. Although the two works are structurally different in several ways, they share an intense Gothic atmosphere and its consequent psychological density, which influences the mental frame of the two protagonists. In order to explore the relations among the structural, social and psychological aspects involved, a reading of the novels has been conducted, focusing on the presence of Gothic elements that stand for the challenges Catherine and Jane are bound to face. Literary critic Eve Kosofsky Sedgwick‘s work The Coherence of Gothic Conventions (1986) is used to identify and contextualise the capacity of Gothic imagery to reveal the weight of social conventions upon the natural process of growth of the two protagonists. Inasmuch as the pressure becomes intensified by the rules of gender settlements, the concept of Female Gothic is explored, as presented by Professor Carol Margaret Davison. Particular attention is paid to the imagery related to space – psychological space for the protagonists to grow emotionally, and physical space, as determinant of where and how they must move. Here the theoretical support is offered by Gaston Bachelard‘s poetics of the primitive elements, unveiling the body of images presented in the two novels. The conclusion indicates the solutions found by Catherine Earnshaw and by Jane Eyre to find their way and overcome the obstacles they meet; with comments on how revealing Gothic imagery is of the social conventions it represents.

University of Macau / Faculty of Social Sciences and Humanities / Department of English

This thesis addresses issues of class as represented through the narrative agency exercised by the servant-narrator in Castle Rackrent and Wuthering Heights. Thady Quirk and Ellen Dean are servant-narrators who strategically use feigned allegiance, astute perception, and selective disclosure to wield power over the lives of their masters. These “arts of subordination” allow the servant-narrator to tell his or her own life narrative, while appearing to share the masters’ memoirs. While both servant-narrators are motivated by economic means, Ellen Dean’s involvement throughout Wuthering Heights is further complicated by her desires of emotional connection. However, each servant-narrator achieves his or her goals by manipulating the events and relationships that constitute his or her masters’ lives.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 265-279). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 265-279). Also available on the Internet.

This research work evaluates the quality of built housing environment and the improvement of the quality of life for the beneficiary communities under the South African Housing Policy. It pays special reference to the Case Study of Waterloo and Quarry Heights within the jurisdiction of Durban Unicity. In order to assess the quality of built housing environment whether it has a potential to improve the quality of life for the client communities the researcher set indicators which are: Integrated planned housing environment, residential quality, suitable building material, secured housing environments, standard of dwelling units, housing environment with economic infrastructure, housing environment that allows fleXibility and extension, and housing environment that has got development infrastructure and social services. These indicators are used in this study as important tool in evaluating the quality of built housing environment. / Thesis (M.Arch.)-University of Natal, 2002.