Thesis (MEd (Curriculum sStudies))--University of Stellenbosch, 2007. / The TRAC PAC is a micro computer-based laboratory that allows learners to collect real-time data about a particular event and then displays the information graphically. It was brought to South Africa from the United States of America in an attempt to increase the low number of learners from previously disadvantaged communities entering the Science, Engineering and Technology fields. Anecdotal evidence has shown that the TRAC PAC has not been optimally utilised in classrooms. Subsequently a TRAC laboratory was established at Stellenbosch University and hence this study, which focused on identifying factors that would contribute towards the optimal use of the TRAC PAC. A qualitative case study research method was used, which relied on different techniques to gather data on how the TRAC PAC is used in classrooms and at the TRAC laboratory. The analysis of this data was largely an intuitive process; it relied on the development of categories which provided insights on the advantages and disadvantages of using the TRAC PAC. The thesis concludes with a number of recommendations that can lead to the optimal use of the TRAC PAC. One of the findings of this study was that even grade 12 Physical Science learners lacked certain basic skills such as the ability to take accurate measurements. Addressing this lack amongst South African learners is also a priority of the National Education Department, following its adoption of an outcomes-based education approach. The design of a detailed, well structured series of activities that addresses the required educational outcomes should result in the optimal use of the TRAC PAC.

Contexte : Les premières implantations PACS (Picture Archiving and Communication System) remontent aux années 80. Le rehaussement récent du PACS au sein d’un centre hospitalier universitaire a permis d’étudier l’introduction d’innovations dans une technologie mature. Objectif : Dans un premier temps, effectuer une revue de la littérature sur les études évaluant la perceptions des utilisateurs de l’implantation des PACS. Deuxièmement, évaluer dans une étude de cas si le niveau d’alignement entre les tâches et la technologie prédit l’utilisation et la perception des bénéfices. Méthodes : Il y a eu une revue systématique de la littérature afin d’identifier les études sur la perception des utilisateurs du PACS. Une adaptation du modèle TTF (Task-Technology-Fit) développé par Goodhue (1995) a servi de base théorique pour l’étude de cas effectuée par questionnaire auto-administré. Résultats : Les modèles recensés dans la revue systématique sont mieux adaptés à des nouvelles implantions PACS qu’à des systèmes matures en évolution. Il y a une corrélation significative entre le niveau de l’alignement, tel que perçu par les utilisateurs, et la perception des bénéfices nets, ainsi que l’utilisation de la technologie. L’étude a démontré un écart entre la perception des utilisateurs et celle des développeurs interviewés. Conclusions : Cette étude supporte la validité du concept alignement tâche-technologie dans l’analyse d’un rehaussement PACS. Il est important de maintenir une interaction soutenue entre développeurs et utilisateurs, qui va audelà de la phase initiale de développement. / Context: The first PACS deployments date to the early 1980’s. The recent upgrade of PACS in a university teaching hospital has offered the opportunity to study the introduction of innovations in a mature technology. Objective: First, to conduct a literature review of studies evaluating user perceptions following deployment of PACS. Second, to evaluate in a case study if task-technology fit predicts utilisation and perceived benefits. Methods: A systematic review of the literature was conducted to identify studies evaluating user perceptions. An adaptation of the Task-Technology-Fit model developed by Goodhue (1995) served as a theoretical basis for the case study conducted with an auto-administered survey. Results: The models used in the studies identified in the review are more suited for initial deployments of PACS, rather than mature systems in a state of continuous evolution. There is a significant correlation between the level of task-technology fit and the users’ perception of net benefits, as well as use. The study also revealed a divide between the perception of users and that of developers involved in product evolution. Conclusion: The findings validate the use of task-technology fit to study a PACS upgrade. It is important to maintain a continuous interaction between users and developers beyond the early phases of product development.

O principal tema desenvolvido nesta tese é o estudo de efeitos nucleares na produção de diléptons por meio do processo Drell–Yan para energias compatíveis com as de RHIC e de LHC. Dois modelos são usados: o formalismo de dipolos de cor e o modelo de pártons com momentum transversal intrínseco. No primeiro capítulo, uma breve introdução histórica e a motivação para o estudo são apresentadas. No Cap. 2, o espalhamento profundamente inelástico (EPI) no modelo de pártons é revisado e são discutidas as distribuições partônicas de prótons (CTEQ) e de nucleons (EKS, EPS08 e EPS09). O EPI no formalismo de dipolos também é discutido. O Cap. 3 é dedicado ao embasamento teórico do formalismo de dipolos e ao estudo das seção de choque de dipolos. As principais equações que governam a evolução de dipolos são expostas, seguidas pelas parametrizações fenomenológicas GBW, DHJ, BUWe ABGS. Um novo modelo é proposto: a parametrização AGBS com flutuações. Quando ajustada aos dados de HERA, a nova parametrização não difere da antiga AGBS, indicando que flutuações não são necessárias para descrever os dados de EPI nas presentes energias. No Cap. 4, é apresentado o modelo de pártons no processo Drell–Yan. O formalismo é discutido em ordem dominante, em ordem seguinte à dominante (OSD) e em OSD com momentum transversal intrínseco, já que apenas na última possibilidade o momentum transversal do dilépton pode ser gerado de maneira consistente com os experimentos. Posteriormente, o formalismo de dipolos aplicado ao mesmo processo é debatido, que em ordem dominante possui distribuição em momentum transversal consistente com os experimentos. Os resultados são cálculos para o fator de modificação nuclear (RpA) para rapidezes negativas como função de rapidez e momentum transversal. A aplicação para rapidezes negativas do formalismo de dipolos é uma contribuição original, bem como a comparação deste formalismo com o modelo de pártons com momentum transversal intrínseco. Efeitos de grande (efeito EMC e anti-sombreamento) e de pequeno x (sombreamento) são observados. Mostra-se que o momentum transversal intrínseco é particularmente importante, alterando o fator de modificação nuclear em torno de 10%. Quando as diferentes parametrizações da seção de choque de dipolos são comparadas, a produção de diléptons não apresenta variações significativas, indicando que ela não é sensível aos detalhes das parametrizações, como a possível violação de escalamento geométrico presente na parametrização DHJ. Adicionalmente, os resultados do modelo de pártons são estendidos para rapidezes positivas e comparados com resultados do condensado de vidros de cor. Para energias de RHIC, os formalismos concordam, enquanto que para LHC, a menos que a parametrização nuclear tenha um sombreamento muito forte (caso da EPS08), os formalismos discordam, devido aos comportamentos distintos do sombreamento de glúons e do sombreamento de quarks. Como perspectiva, é discutido o modelo unidimensional, que é uma simplificação drástica da evolução de dipolos sem deixar de incluir os efeitos de flutuações. Em particular, as possibilidades de escalamento geométrico e escalamento difusivo nas seções de choque são discutidas. / The main topic of this thesis is the study of nuclear effects in Drell–Yan dilepton production at RHIC and LHC energies. Two approaches are employed: the color dipole approach and the parton model with intrinsic transverse momentum. In the first chapter, a brief introduction and the motivation to the study are presented. Chapt. 2 reviews the deep inelastic scattering (DIS) in the parton model and the parton distribution functions of protons (CTEQ) and of nucleons (EKS, EPS08 e EPS09) are examinated. The DIS in the dipole frame is also discussed. Chapt. 3 reviews the theoretical foundations of the color dipole approach and the dipole cross section. The main equations that drive the dipole evolution are shown, followed by the phenomenological parameterizations GBW, DHJ, BUW, and ABGS. A new model is proposed: the AGBS parameterization with fluctuations. When fitted to HERA data, the new parameterization does not differ from the old AGBS, indicating that fluctuations are not needed to reproduce DIS data at current energies. Chapt. 4 discusses the parton model in the Drell–Yan process. This approach is considered at leading order, at next-to-leading order (NLO), and at NLO with intrinsic transverse momentum, as only in the last case the dilepton transverse momentum distribution can be obtained in agreement with experiments. Afterwards, the color dipole approach applied to the process is examined, giving at leading order a transverse momentum distribution compatible with experiments. The results are calculations to the nuclear modification factor (RpA) at backward rapidities as function of rapidity and transverse momentum. The use of backward rapidities of the color dipole approach is an original contribution, as well as the comparison of this approach with the parton model with intrinsic transverse momentum. Effects of large (EMC effect and antishadowing) and of small x (shadowing) are seen. It is shown that the intrinsic transverse momentum is particularly important, changing the nuclear modification factor of about 10%. When different parameterizations of the dipole cross section are compared, the dilepton production does not show significant discrepancies, suggesting the it is not sensitive to the parametrization details, such as the possibility of geometric scaling breaking present in DHJ parameterization. Furthermore, the parton model results are extended to forward rapidities and compared with results of the color glass condensate. At RHIC energies, the approaches agree, while at LHC energies, unless the nuclear parameterization shows a very strong nuclear shadowing (EPS08 case), the approaches disagree, due to the different behaviors of gluon shadowing and quark shadowing. The unidimensional model, a toy model of the dipole evolution that includes the fluctuation effects is also investigated. Specificaly, the possibilities of geometric scaling and difusive scaling in cross sections are discussed.

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2008年釋字第647號公布，針對稅法上未賦予「事實上夫妻」法律上配偶相同待遇，是否牴觸憲法做出解釋。其理由書謂無配偶之人相互間主觀上具有如婚姻之共同生活意思，客觀上亦有共同生活事實之異性伴侶，雖不具法律上婚姻關係，但既與法律上婚姻關係之配偶極為相似，如亦有長期共同家計之事實者，因具婚姻關係配偶之相似性，立法機關得在無損於婚姻制度或其他相關公益之前提下，給予適度之法律保障。之前於2007年通過民法修正，將婚姻制度由過去「儀式婚」改為「登記婚」，不過社會上迎娶的習俗並未改變，男女只踐行婚禮而未為結婚登記者，其法律地位如何。而各國同居人口不斷增加，各國法制莫不積極因應，據調查國內目前同居人口亦高達44萬人以上，因此外國法制確有參考的實益。礙於篇幅及文獻限制，僅就人民往來頻仍之美國、率先以民法典規範之法國、以裁判先例處理之日本、文化背景近似之中國大陸等地介紹之。 　　本論文分六章，第一章介紹研究動機及研究方法，研究之動機主要是大法官釋字第647號解釋之立法指示、2008年結婚方式修正後預立補強之道。其研究方法係以法解釋學為基礎，透過文義、體系、立法、目的及合憲解釋等方法認識各國法制，再進行法制間的比較、歸納、演繹等分析，期能借鑑最適我國情之法制。第二章為各國事實婚之用語、規範類型與發展介紹。以較宏觀的角度檢視各國事實婚法制，包括其用語、規範的方式及發展背景，各國對於事實婚的表達未必一致，如何擷取具有參考價值的法制，成為研究事實婚的第一個課題。其次規範的方式各國間亦不相同，有以成文法規範之，亦有以裁判先例處理之，甚至解決的重心亦不相同；而各國事實婚形成的背景，更是研究外國法制所不可或缺者。第三章討論事實婚保護之法理，一般認為事實婚的保護，將有害婚姻憲法權威地位，承認事實婚之地位必須具有強而有力的理由。目前雖然沒有事實婚的國際條約，不過婚姻自由、家庭保護、平等不歧視、兒童保護等國際法上普世原則的尊重，亦間接保護事實婚。而已進行事實婚保障之國家，其調整憲法上婚姻地位獨尊的論述，亦值得參考。第四章、第五章則具體分析美、法、日、中國大陸等地關於事實婚之規定，包括美國法律協會的家庭解消建議、法國民法Pacs制度、日本內緣關係、中國大陸之（非法）同居關係等，同時分析我國司法實務的判決。 　　第六章為結論，本論文肯定事實婚保護之必要性，強調共同生活事項類推婚姻法效果的合理性，並根據此結論提出建議，包括援引外國立法例的調整、國內實務解釋的改進、立法雛議與男女共同生活契約範本的提出，期能增進男女地位的公平與弱勢伴侶之保護。 / The reasoning of J. Y. Interpretation no.647 has pointed out ”Those unmarried companions of opposite sex with a subjective intent to live together like a married couple and the objective fact of cohabitation do not have a matrimonial relation in law, the relationship between them is very much similar to the relationship of legally married husband and wife, and the provision at issue, which does not provide for gift tax exemption for mutual gifts between such companions, would seem susceptible to a doubt of violating the principle of equality provided that there is in addition a fact of longtime sharing of the livelihood between such couples. As for those cohabited companions with similarity to a legal marriage, the Legislature may, taking into considerations the constitutional protection of fundamental rights of the people as well as changes in the social condition and cultural development, give them adequate legal protection to the extent not disparaging marriage institution and other public interests.” Though the formal requirement of validity of marriage in Civil Law in Taiwan has changed from ceremony to registration since 2007, it is generally recognized that a valid marriage should be done on the basis of a marriage ceremony, by which a gap between citizen’s perception and legal norms has come out and the commence of de facto marriage becomes inevitable. Furthermore, the amounts of cohabitation in Europe and the United States have increased constantly so that the legislation of long-term de facto marriage has more or less been made in these countries. In contrast, though the amounts of cohabitation in Taiwan is estimated to exceed 0.4 million, the judicial practices for the legal issue of cohabitation are not coherent among cases in courts. Accordingly, this thesis focuses on the comparison of legislation for de facto marriage among several countries with a view to providing some suggestions to the law making and judicial practice in Taiwan. Firstly, the motivation and methodologies are introduced in chapter one. As to methodologies, this thesis starts from the interpretation of law; and comparative, inductive and deductive approaches are used for the research of legal systems in some countries. Secondly, this thesis analyses the terminology, types of legislation and development of de facto marriage in chapter two. Inter alia, it includes the definition of de facto marriage made by Chinese, Japanese and English-speaking scholars and the models of legislation for the protection of de facto marriage in some countries. In addition, it elaborates the background of de facto marriage and its evolution of legal regime in the United States, France, Japan and China. In chapter three, it deliberates the legal basis of de facto marriage. It commences from the stipulation of international treaties, in particular the European Convention on Human Rights, and the judicial practices of the European Court of Human Rights on the issues of freedom of marriage, protection of family rights, non-discrimination and the best benefits for children. It then compares the pros and cons for the protection of de facto marriage so that its necessity and possibility could be established at the constitutional level. In chapter four, this thesis elaborates the requirements of de facto marriage in United States, France, Japan and China, for instance, the Recommendations of Family Dissolution made by the American Law Institute (ALI), the Pacs in France, “Nai En” system in Japan and the (illegal) cohabitation in China. Furthermore, it also analyses Taiwan’s legal system of de facto marriage. This thesis then discusses in chapter five the legal effects of de facto marriage in the United States, France, Japan and China, and their impact on Taiwan’s related legislation. Finally, it concludes in chapter six by recognizing the necessity to protect de facto marriage and the legitimacy to analogize the legal effect of marriage law to common life matters. Accordingly, this thesis suggests that foreign legislations be ushered in for the amendment of domestic laws; the improvement of the interpretation of domestic judicial practices be made, and model contract for cohabitation be proposed in order to improve the fair status between male and female and the protection for the weaker one of the couple.

Les activités du Laboratoire de recherche en Électronique, Électrotechnique et Systèmes (L2ES) sont dans le champ des transports que ce soit pour la génération d'énergie au moyen de PACs ou pour la chaîne de traction. Les travaux de recherche, dans ce dernier domaine, portent essentiellement sur les MSAPs à entraînement direct lent du type synchrone avec balais ou autopiloté à commande trapézoïdale ou sinusoïdale.<br />L'objectif consiste maintenant à orienter les recherches vers les actionneurs à vitesse élevée. Une application importante concerne l'entraînement de compresseurs pour le système PAC. Des études menées au L2ES ont montré que les turbocompresseurs constituaient une solution intéressante pour limiter la taille et la puissance absorbée.<br />Nous proposons dans cette thèse de mettre au point une méthodologie de conception de MSAPs montés en surface à vitesse élevée en vue de leur optimisation en prenant en considération les contraintes magnétiques, électriques et thermiques. Cette méthodologie prend en compte des contraintes spécifiques de la grande vitesse, et notamment les pertes électromagnétiques dans la partie tournante induites par la fréquence élevée d'alimentation. Les pertes magnétiques dans l'induit denté créées par une aimantation radiale ou parallèle des aimants permanents sont également modélisées. En effet, deux modèles analytiques complexes (magnétostatique et magnétodynamique) ont été développés pour prédire ces pertes fer significatives dans les MSAPs sans pièces polaires à inducteur intérieur ou extérieur. La méthode est générale, parce qu'elle est basée sur le calcul de champ électromagnétique bidimensionnel (2D) en coordonnées polaires (résolution des équations de Laplace/Poisson/Diffusion). L'analyse prend en compte les notions de courbures, les harmoniques de temps et d'espace de la répartition des courants de l'induit produite par un bobinage quelconque, l'effet du champ de réaction d'induit par courant de Foucault, et enfin différentes configurations de bobinages statoriques ("généralisation" des bobinages) ainsi que deux types d'aimantation (radiale et parallèle). L'hypothèse principale consiste dans le fait que l'on néglige la variation de perméance due au stator denté. Les contraintes mécaniques ont été traitées en liaison avec le mécanicien de la société NOVELTE Système de Belfort (90).<br />La MSAP réalisée tourne à 10 000 tr/min avec un résolveur analogique "sin-cos" à aimants permanents constitué de capteurs à effet Hall. Le moteur construit servira de base de validation dans la zone de vitesse concernée (i.e., de 0 à 10 000 tr/min).

Nous proposons dans cette recherche une solution nouvelle quant à l'existence et à la nature de la singularité initiale d'espace-temps. Dans le contexte de la supergravité N=2 et de la théorie topologique des champs, nous considérons que la singularité initiale d'espace-temps correspond à un instanton gravitationnel singulier de taille zéro caractérisé par une configuration Riemanienne de la métrique (++++) en dimension D = 4. Associée à un état topologique correspondant à l'échelle zéro de l'espace-temps, la singularité initiale n'est pas ici considérée en termes de divergences des champs physiques, mais peut être résolue dans la cadre de la théorie topologique des champs. Nous obtenons ce résultat à partir de l'observation physique selon laquelle le pré espace-temps doit être considéré en équilibre thermique à l'échelle de Planck. En conséquences, nous suggérons de manière naturelle qu'à l'échelle de Planck l'espace-temps à l'équilibre doit être soumis à la condition KMS. Dans ce contexte, l'état KMS dans lequel se trouve le pré espace-temps à l'échelle de Planck pourrait être interprété comme le résultat d'une unification entre " état physique" (métrique lorentzienne +++-) et "état topologique" (métrique riemanienne ++++). Ceci correspond à la phase d'oscillation quantique de la signature de la métrique déjà mise en évidence dans des travaux antérieurs. Nous suggérons alors que "la singularité d'échelle zéro" doit être comprise en termes d'invariants topologiques, en particulier le premier invariant de Donaldson. En conséquences, nous proposons ici un nouvel invariant topologique, asssocié à l'échelle 0 et de la forme Z = TR (-1)s, que nous appelons "invariant de singularité". Enfin, dans ce contexte, nous proposons la conjecture selon laquelle le problème de l'interaction inertielle pourrait être expliqué en termes d'amplitude topologique liée à l'instanton gravitationnel singulier caractérisant, dans notre approche, l'échelle zéro de l'espace-temps.

In a time when record numbers of dollars are being spent on campaigns the unregulated dollars are flowing faster than ever. Hundreds of millions of dollars in independent expenditures are being used for “issue advocacy”, print and broadcast advertising, which does not expressly endorse or oppose a candidate for office. The one-time campaign finance ceiling has become the campaign finance basement. Individuals are able to give unlimited dollars to 527 organizations, which function outside of all campaign finance regulation and provide a new path for the flow of political dollars. Since the passage of the Bipartisan Campaign Reform Act, commonly known as the McCain-Feingold Act, federally regulated lobbyists and PACS are being edged out of the political dollar due to contribution limits. It is in 1996 that we witness the birth of 527 organizations and the flourishing growth of soft money spending in the campaign process.

Contexte : Les premières implantations PACS (Picture Archiving and Communication System) remontent aux années 80. Le rehaussement récent du PACS au sein d’un centre hospitalier universitaire a permis d’étudier l’introduction d’innovations dans une technologie mature. Objectif : Dans un premier temps, effectuer une revue de la littérature sur les études évaluant la perceptions des utilisateurs de l’implantation des PACS. Deuxièmement, évaluer dans une étude de cas si le niveau d’alignement entre les tâches et la technologie prédit l’utilisation et la perception des bénéfices. Méthodes : Il y a eu une revue systématique de la littérature afin d’identifier les études sur la perception des utilisateurs du PACS. Une adaptation du modèle TTF (Task-Technology-Fit) développé par Goodhue (1995) a servi de base théorique pour l’étude de cas effectuée par questionnaire auto-administré. Résultats : Les modèles recensés dans la revue systématique sont mieux adaptés à des nouvelles implantions PACS qu’à des systèmes matures en évolution. Il y a une corrélation significative entre le niveau de l’alignement, tel que perçu par les utilisateurs, et la perception des bénéfices nets, ainsi que l’utilisation de la technologie. L’étude a démontré un écart entre la perception des utilisateurs et celle des développeurs interviewés. Conclusions : Cette étude supporte la validité du concept alignement tâche-technologie dans l’analyse d’un rehaussement PACS. Il est important de maintenir une interaction soutenue entre développeurs et utilisateurs, qui va audelà de la phase initiale de développement. / Context: The first PACS deployments date to the early 1980’s. The recent upgrade of PACS in a university teaching hospital has offered the opportunity to study the introduction of innovations in a mature technology. Objective: First, to conduct a literature review of studies evaluating user perceptions following deployment of PACS. Second, to evaluate in a case study if task-technology fit predicts utilisation and perceived benefits. Methods: A systematic review of the literature was conducted to identify studies evaluating user perceptions. An adaptation of the Task-Technology-Fit model developed by Goodhue (1995) served as a theoretical basis for the case study conducted with an auto-administered survey. Results: The models used in the studies identified in the review are more suited for initial deployments of PACS, rather than mature systems in a state of continuous evolution. There is a significant correlation between the level of task-technology fit and the users’ perception of net benefits, as well as use. The study also revealed a divide between the perception of users and that of developers involved in product evolution. Conclusion: The findings validate the use of task-technology fit to study a PACS upgrade. It is important to maintain a continuous interaction between users and developers beyond the early phases of product development.

Floodplain lakes are strongly regulated by river connectivity because floodwaters exert strong influence on the water balance, the physical, chemical and biological limnological conditions, and the influx of contaminants. The Peace-Athabasca Delta (PAD) in northern Alberta (Canada) is a hydrologically complex landscape and is an important node in the upper Mackenzie River Drainage Basin. The ecological integrity of the PAD is potentially threatened by multiple environmental stressors, yet our understanding of the hydroecology of this large floodplain remains underdeveloped. Indeed, ever since the planning and construction of the WAC Bennett Dam (1960s), concerns have grown over the effects of upstream human activities on the lakes of the PAD. More recently, concerns over the health of the PAD have intensified and come to the fore of national and international dialogue due to water abstraction and mining and processing activities by the rapidly expanding oil sands industry centred in Fort McMurray Alberta. Currently, widespread perception is that upstream human activities have reduced water levels and frequency of flooding at the PAD, which have lowered nutrient availability and productivity of perched basin lakes, and have increased supply of pollutants from oil sands. However, these perceptions remain based on insufficient knowledge of pre-impact conditions and natural variability. Current and past relations between hydrology and limnology of PAD lakes are mostly undocumented, particularly during the important spring freshet period when the effects of river flood waters are strongest. Similarly, knowledge of the deposition of oil-sands- related contaminants in the PAD remains insufficient to determine whether anthropogenic activities have increased the deposition of important oil-sands-related contaminants such as polycyclic aromatic compounds (PACs) relative to natural processes. Such knowledge gaps must be filled to achieve effective monitoring, policy and governance concerning impacts of industrial development and the protection of human and environmental health within the PAD and Mackenzie drainage basin. This thesis examines the effects of river flooding (and the lack of) on water clarity, nutrients, chemistry, phytoplankton abundance, epiphyton community composition and the deposition of polycyclic aromatic compounds (PACs) in lakes of the Peace-Athabasca Delta. To determine the role of flooding on contemporary epiphytic diatom communities (an abundant and diverse guild of primary producers in PAD lakes), a field experiment was conducted examining the community composition and abundance of epiphytic diatoms in four PAD lakes. Two of these four lakes had received floodwaters that spring and two had not. Epiphytic diatom communities in each lake were sampled during the peak macrophyte biomass period (summer) from two macrophyte taxa (Potamogeton zosteriformis, P. perfoliatus var. richardsonii) and from polypropylene artificial substrates previously deployed that spring. A two-way analysis of similarity (ANOSIM) test identified that epiphytic diatom community composition differed between lakes that flooded and those that did not flood. From the use of similarity percentage (SIMPER) analysis, diatom taxa were identified that discriminate between flooded and non-flooded lakes. The relative abundance of ‘strong flood indicator taxa’ was used to construct an event-scale flood record spanning the past ~180 years using analyses of sedimentary diatom assemblages from a closed-drainage lake (PAD 5). Results were verified by close agreement with an independent paleo-flood record from a nearby flood-prone oxbow lake (PAD 54) and historical records. Comparison of epiphytic diatoms in flooded and non-flooded lakes in this study provides a promising approach to detect changes in flood frequency, and may have applications for reconstructing other pulse-type disturbances such as hurricanes and pollutant spills. Additionally, this study demonstrates that artificial substrates can provide an effective bio-monitoring tool for lakes of the PAD and elsewhere. To improve our understanding of the hydrolimnological responses of lake in the PAD to flooding, repeated measurements over three years (2003-05) were made on a series of lakes along a hydrological gradient. This allowed the role of river flooding to be characterized on limnological conditions of lakes and to identify the patterns and timescales of limnological change after flooding. River floodwaters elevate lake water concentrations of suspended sediment, total phosphorus (TP), SO4 and dissolved Si (DSi), and reduce concentrations of total Kjeldahl nitrogen (TKN), DOC and most ions. River flooding increases limnological homogeneity among lakes, because post-flood conditions are strongly affected by the river water properties. After floodwaters recede, limnological conditions become more heterogeneous among lakes in response to diversity of local basin influences (geology, slope, vegetation, depth, fetch, and biological communities and processes), and limnological changes occur at two distinct timescales. In the weeks to months after flooding, water clarity increases as suspended sediments and TP settle out of the water column. In the absence of flooding for many years to decades, evaporative concentration leads to an increase in most nutrients (TKN, inorganic N, and dissolved P), DOC and ions. Contrary to a prevailing paradigm, these results suggest that regular flooding is not required to maintain high nutrient concentrations. In light of anticipated declines in river discharge, limnological conditions in the southern Athabasca sector will become increasingly less dominated by the short-term effects of flooding, and resemble nutrient- and solute-rich lakes in the northern Peace sector that are infrequently flooded. To determine the roles of the Athabasca River and atmospheric transport as vectors for the deposition of PACs in the PAD, sediment cores spanning the last ~200 years were collected from three lakes within the delta. A closed-drainage basin elevated well above the floodplain (PAD 18) was selected to determine temporal patterns of change in PAC concentration due to atmospheric deposition and within-basin production of PACs. Known patterns of paleohydrological changes at the other two lakes (PAD 23 and 31) were used to assess the role of the Athabasca River in delivering PACs to the Athabasca Delta during the ~200 year. Well- dated sediment core samples were analysed for 52 alkylated and non-alkylated PACs (method EPA 3540/8270-GC/MS). Sediments deposited in the non-flood prone lake (PAD 18) contained lower concentrations of total PACs compared to sediments deposited during flood-prone periods in the other study lakes, and were dominated by PACs of a pyrogenic rather than bitumen origin. Multivariate analysis of similarity tests identified that the composition of PACs differs between sediments deposited during not flood-prone and flood-prone periods. Subsequent Similarities Percentage (SIMPER) analysis was used and identified seven PACs that are preferentially deposited during flood-prone periods. These seven PACs are bitumen-associated, river-transported and account for 51% of the total PACs found in oil-sands sediment. At PAD 31, which has been flood-prone both before and since onset of Athabasca oil sands development, identified no measureable differences in both the proportion and concentration of the river-transported indicator PACs in sediments deposited pre-1940s versus post-1982. Our findings suggest that natural erosion of exposed bitumen along the banks of the Athabasca River and its tributaries is the main process delivering PACs to the Athabasca Delta, and that the spring freshet is a key period for contaminant mobilization and transport. Such key baseline environmental information is essential for informed management of natural resources and human-health concerns by provincial and federal regulatory agencies and industry, and for designing effective long-term monitoring and surveillance programs for the lower Athabasca River watershed in the face of future oil sands development. Further monitoring activities and additional paleolimnological studies of the depositional history of PACs and other oil-sands- and non-oil-sands-related contaminants is strongly recommended. Overall, results of this research identify that river flooding exerts strong control on physical, chemical and biological conditions of lakes within the PAD. However, contrary to prevailing paradigms, the PAD is not a landscape that has been adversely and permanently affected by regulation of the Peace River and industrial development of the oil sands along the Athabasca River. Instead, data from contemporary and paleolimnological studies identify that natural processes continue to dominate the delivery of water and contaminants to the delta. Regular and frequent flooding is not essential to maintain the supply of nutrients and productivity of delta lakes, which has been a widespread paradigm that developed in the absence of objective scientific data. Instead, nutrient concentrations rise over years to decades after flooding and lake productivity increases. During the thesis research, novel approaches were developed and demonstrated to be effective. Namely, new artificial substrate samplers were designed for aquatic biomonitoring that accrue periphyton and can identify the occurrence of flood events. Also, paleolimnological methods were employed to characterize the composition and concentration of PACs supplied by natural processes prior to oil sands industrial activity, which serves as an important benchmark for assessing industrial impacts. These are effective methods that can be employed to improve monitoring programs and scientific understanding of the factors affecting this world-renowned landscape, as well as floodplains elsewhere.