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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Spin-selective chemical reactions in radical pair magnetoreception

Lau, Jason C. S. January 2014 (has links)
Many animals on earth need to navigate in their own environments for breeding and foraging. The ability to determine a correct heading and the current location for a migratory bird is critical for its survival. Animals that are sensitive to the Earth’s magnetic field can use it to obtain their direction of travel. In 2000, a paper suggested that radical pair reaction could form the basis for magnetoreception in migratory birds and a flavoprotein, cryptochrome, was proposed as the candidate for the radical pair precursor. Recent in vivo experimental results strongly support the hypothesis that radical pairs formed in the eyes of migratory birds are responsible for their magnetic compass sense. Cryptochrome has also been located in the UV-cones in the retinas of two different species of bird. Radical pairs in living cells are influenced mainly by Zeeman interaction, hyperfine interaction, rotational modulation, etc., and together they influence the recombination reactions of the radical pairs. This thesis considers the possible role of radical pairs in avian magnetoreception, using computer simulations of the quantum mechanical evolution of a radical pair under a variety of conditions. Chapter 1 contains the introductions to spin chemistry, avian magnetoreception, and the mathematical description of the quantum evolution of a radical pair. Chapter 2 describes the four different theoretical models for a general non-diffusion-controlled radical pair reaction and the product yields of a radical pair reaction predicted by these four models are analysed and compared. Chapter 3 introduces a model for avian magnetoreception that integrates photoselection with the radical pair reaction and the model is used to predict the retinal patterns that a bird may be able to use for magnetoreception. The anisotropic singlet product yields of a radical pair comprises the flavin chromophore and the tryptophan of a cryptochrome are also presented in this chapter. A paper based on some parts of this chapter is published [1] in the Journal of The Royal Society Interface. Chapter 4 describes a modified version of an algorithm that is used to calculate the product yields detected in a reaction yield detected magnetic resonance (RYDMR) experiment. The new algorithm is used to analyse the results of two sets of RYDMR experiments in which two radical pair systems, pyrene/1,3-dicyanobenzene and chrysene/1,4-dicyanobenzene, were used. The modulated detection technique used in the RYDMR experiments is also discussed in this chapter.
292

When Resistance is Not Enough: The Role of Ecotage in Radical Environmentalism

Brown, Kris R 01 January 2010 (has links)
As a starting point, I've created a simple, five step argument for my view on humanity's environmental responsibility. The first four steps are premises upon which I will elaborate to some degree over the course of this paper, and the fifth step is a conclusion that should necessarily follow from the premises if they are true. 1) Humans are currently threatening the earth's viability as a habitat for living thing. 2) Humans have a duty not to threaten the earth's viability as a habitat for living things. 3) Our duty not to threaten the viability of the earth as a habitat for living things is stronger than our duty to obey the law. 4) The exclusive use of traditional, legal attempts to change patterns of human behavior to eliminate their threat to the earth's viability as a habitat for living things is and will always be ineffective. 5) Therefore, when our duty not to threaten the earth's viability as a habitat for living things conflicts with our duty to obey the law, we ought first to satisfy the former.
293

The Impact of Radical Innovation on Consumer Behaviour : A case study of iPhone

Ungsusing, Antika, Pinyotrakool, Phromporn January 2009 (has links)
No description available.
294

An Electron Bombardment-Matrix Isolation Study of the Tropospheric Reactions of Toluene

Campbell, Sasha Erin 26 November 2013 (has links)
The tropospheric reactions of toluene, acting as a model VOC, are investigated using an electron bombardment-matrix isolation system coupled with Fourier transform infrared spectroscopy. Initial experiments to produce the hydroxyl radicals used to initiate the toluene reactions via electron bombardment of water-argon mixtures are performed. The effects of electron current, water concentration, and gas flow rate are investigated. A more efficient method of initiating the toluene reactions, by directly creating benzyl radicals through electron bombardment of toluene is then investigated, and the effects of toluene concentration and electron current on the production of the benzyl radicals is quantified. Benzyl radicals are successfully produced, and identified via FT-IR. The next step is the formation of benzylperoxy radicals, via electron bombardment of toluene-oxygen-argon gas mixtures. Experiments are performed using increasing concentrations of toluene and oxygen, in an attempt to observe the benzylperoxy radical. Two new absorptions are observed in the infrared spectra and are tentatively identified as due to the peroxy group on the benzylperoxy radical. Computational work is also performed to confirm that benzylperoxy radicals can in fact be produced from benzyl radicals and oxygen. The vibrational frequencies of the benzylperoxy radical are also calculated, and used to confirm the possibility that the new absorptions seen in the infrared spectra could in fact be due to benzylperoxy radicals. The overall results from this work demonstrate that it is likely to be possible to use electron bombardment-matrix isolation systems to investigate tropospheric reactions of volatile organics, and that further experiments could be enhanced by structural modifications to the system. / Thesis (Master, Chemistry) -- Queen's University, 2013-11-26 15:57:59.4
295

Memory, Modernity, and the City: An Interpretive Analysis of Montreal and Toronto's Respective Moves From Their Historic Professional Hockey Arenas

Gunderson, Lisa January 2004 (has links)
This thesis seeks to understand how and if the popular claims that hockey is an integral part of the culture in Toronto and Montreal are referenced, oriented to, and/or negotiated in everyday life. Taking the cases of the moves of the Toronto Maple Leafs and the Montreal Canadiens from Maple Leaf Gardens and the Montreal Forum, respectively, the thesis asks: What can these similar cases tell us about the culture of the cities in which they occurred and, if it is possible, in what ways can the culture of the cities (as a shaping force) be made recognizable in the discourse generated in, around, and by the moves? The perspective taken is a 'radical interpretive' approach, involving a critical blend of interpretive theories and methodologies - including semiology, phenomenology, hermeneutics, and dialectical analysis - that aim to reflexively question the themes that the cases themselves bring to light. The thesis thus concerns itself with issues of cosmopolitanism, globalization, and modernity as well as the concomitant questions of identify, commitment to place, and practical social action in the modern city.
296

Dioxygen free radical reactions

Barreto, Joao Pedro Cabaco Moniz January 1997 (has links)
No description available.
297

Truth evaluability in radical interpretation theory

Manolakaki, Eleni January 2000 (has links)
The central problem of the dissertation concerns the possibility of a distinction between truth-evaluable and non-truth-evaluable utterances of a natural language. The class of truth-evaluable utterances includes assertions, con. ectures and other kinds of speech act susceptible of truth evaluation. The class of non-truth-evaluable utterances includes commands, exhortations, wishes i.e. utterances not evaluated as being true or false. The problem is placed in the context of radical interpretation theory and it shown that it is a substantial problem of Davidson‘s early theory of radical interpret at ion. I consider the possibility of distinguishing between locutionary and illocutionary act in uttering a sentence and its significance in the present project. I discuss the suggestion that the mood of the verb of the sentence signifies the required distinction between truth-evaluable utterances and non-truth-evaluable ones. I argue that no criterion for the distinction based on the mood of the verb is adequate. The solution that I propose to the problem of classifylng truth-evaluable utterances appeals to mental states. The view that grounds this line of inquiry is that the truth-evaluability of an utterance is a characteristic of it exclusively relevant to the doxastic dimension of the speaker’s mind. I discuss the constraints that the nature of radical interpretation puts upon the way we construe the notion of belief. I propose that a possible classification of mental states into doxastic and non-doxastic that would result in a classification of utterances into truth-evaluable and non-truthevaluable ones can be given by an elaborated version of a decision theoretic scheme. I suggest that a decision theoretic scheme based on a decision theory that, like Savage’s theory, grants independence axioms is a better candidate to offer a solution to the central problem of the dissertation than a scheme based on a non- standard decision theory such as Richard Jeffrey’s. I conclude by showing that the proposal I make satisfies the constraints I have considered and that it can be accommodated by a radical interpretation theory.
298

Structure Properties of Heterophase Hairy-Nanoparticles: Organic vs. Inorganic

Person, Vernecia 28 July 2015 (has links)
Substances that consist of nano-scale fillers dispersed in a polymer matrix are known as polymer-nanocomposites (PNCs). These materials are appealing since they have high potentials for applications, due to their mechanical, electrical, and thermo electrical properties. A common problem associated with PNCs is that the nano-fillers have a tendency to aggregate into clusters and form phase separated domains, which cause the desired properties of the system to either diminish or vanish all together. Hairy nanoparticles (HNPs) can avoid the issue of agglomeration that is commonly encountered by conventional PNCs. When polymer chains are grafted to a nanoparticle, and the coverage is high, the nanoparticles have decreased inter-particle interactions which allows for enhanced dispersion and mixing into a polymer matrix. By tailoring the architecture (functionalization of polymer chains, degree of polymerization, grafting density) of HNPs, it is possible to control the final properties of the system. An in depth study was carried out to investigate the effects of hairy-nanoparticle architecture on the resulting properties of the material itself. Atom transfer radical polymerization and living anionic polymerization were used to synthesize the polymer chains, of the HNP systems, while various instrumental methods including differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were utilized to study the physical ageing affects and self-assembly of these systems. #88ABW-2015-4971
299

Le mal dans les génocides : une banalité ou une radicalité essai de philosophie morale appliquée

Deschênes, Patrick January 2005 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
300

Globaliseringens vinnare och förlorare : En studie av mekanismerna bakom stöd för högerradikala partier i 14 EU-länder

Callermo, Frida January 2017 (has links)
Can individuals support for radical right parties in European countries be explained as a consequence of globalization? This quantitative study proceeds from the cleavage theory and examines the theory of winners and losers of globalization by studying the importance of three mechanisms on a micro level. It compares the importance of the economic, cultural and political mechanisms effect on individual support for radical right parties in countries within the European Union.  The study finds evidence that supports the theory of winners and losers of globalization and evidence that indicates that the cultural mechanism is the most important of the three to explain individual support for radically right parties.

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