The rate at which stars have formed throughout the history of theuniverse is not constant, it started out slow, increased until around redshift ∼ 2 when it reversed and became slower again. The reason for this behaviour is still being investigated with various models and simulations usually based upon dark matter halos. The aim of this study is to instead investigate whether there is a correlation between the cosmic star formation rate and the evolution of cosmic voids. This is achieved by comparing the total mass flow from voids with the amount of matter forming stars. A simple model of void mass flow is created and compared with observational data of star formation. The model is shown to exhibit the same behaviour as the star formation rate indicating that there is indeed a correlation between void evolution and star formation. This suggests it to be fruitful to create a more involved, alternative model of star formation based upon void evolution as opposed to the common halo evolution / Hur snabbt stjärnor bildas har genom universums historia förändrats över tid, det började långsamt och ökade sedan fram till rödförskutning ∼ 2 då trenden vände och saktade ner igen. Förklaringen till detta beteende utforskas fortfarande genom diverse modeller och simularingar som vanligtvis bygger på mörk materia halos. Syftet med detta arbete är att istället undersöka ifall det finns en korrelation mellan tomrumsutveckling och den kosmiska stjärnbildningen. Detta åstadkoms genom att jämföra det totala massflödet från tomrum med den massa som bildar stjärnorna. En simpel model för tomrumsutveckling skapas och jämförs med observationell data för stjärnbildningshastighet. Denna modell visar samma beteende som stjärnbildningen och tyder på att det finns en korrelation mellan denna och tommrumsutveckling. Som slutsats pekar denna studie på att det kan vara fruktbart att utveckla en mer anancerad modell för den kosmiska stjärnbildningen som bygger på tomrumsutveckling istället för mörk materia halos.

Until recently, numerical modulation models for the solar modulation of cosmic rays have been based primarily on finite difference approaches; however, models based on the solution of an appropriate set of stochastic differential equations have become increasingly popular. This study utilises such a spatially three-dimensional and time-stationary model, based on that of Strauss et al. (2011b). The remarkable numerical stability and powerful illustrative capabilities of this model are utilised extensively and in a distinctly comparative fashion to enable new insights into the processes of modulation. The model is refined to provide for both the Smith-Bieber (Smith and Bieber, 1991) and Jokipii-Kota (Jokipii and Kota, 1989) modifcations to the Parker heliospheric magnetic field (Parker, 1958) and the implications for modulation are investigated. During this investigation it is conclusively illustrated that the Parker field is most conducive to drift dominated modulation, while the Jokipii-Kota and Smith-Bieber modifcations are seen to induce successively larger contributions from diffusive processes. A further refinement to the model is the incorporation of a different profile for the heliospheric current sheet. This profile is defined by its latitudinal extent given by Kota and Jokipii (1983), as opposed to the profile given by Jokipii and Thomas (1981). An extensive investigation into current sheet related matters is launched, illustrating the difference between these current sheet geometries, the associated drift velocity fields and the effect on modulation. At high levels of solar activity, such that the current sheet enters deep enough into the polar regions, the profile of Kota and Jokipii (1983) is found to significantly reduce the effective inward (outward) drifts of positively (negatively) charged particles during A > 0 polarity cycles. The analogous effect is true for A < 0 polarity cycles and the overall effect is of such an extent that the A > 0 and A < 0 solutions are found to coincide at the highest levels of solar activity to form a closed loop. This is a result that has never before been achieved without having to scale down the drift coefficient to zero at solar maximum, as was done by e.g. Ndiitwani et al. (2005). Furthermore, it is found that the drift velocity fields associated with these two current sheet profiles lead to significant differences in modulation even at such low levels of solar activity where no difference in the geometries of these profiles are yet in evidence. The model is finally applied to reproduce four observed galactic proton spectra, selected from PAMELA measurements (Adriani et al., 2013) during the atypical solar minimum of 2006 to 2009; a new proton local interstellar spectrum was employed. The results are found to be in accordance with that found by other authors and in particular Vos (2011), i.e. the diffusion was required to consistently increase from 2006 to 2009 and, in addition, the rigidity dependence below ~ 3 GV was required to change over this time so that the spectra became increasingly softer. / MSc (Space Physics), North-West University, Potchefstroom Campus, 2015

Until recently, numerical modulation models for the solar modulation of cosmic rays have been based primarily on finite difference approaches; however, models based on the solution of an appropriate set of stochastic differential equations have become increasingly popular. This study utilises such a spatially three-dimensional and time-stationary model, based on that of Strauss et al. (2011b). The remarkable numerical stability and powerful illustrative capabilities of this model are utilised extensively and in a distinctly comparative fashion to enable new insights into the processes of modulation. The model is refined to provide for both the Smith-Bieber (Smith and Bieber, 1991) and Jokipii-Kota (Jokipii and Kota, 1989) modifcations to the Parker heliospheric magnetic field (Parker, 1958) and the implications for modulation are investigated. During this investigation it is conclusively illustrated that the Parker field is most conducive to drift dominated modulation, while the Jokipii-Kota and Smith-Bieber modifcations are seen to induce successively larger contributions from diffusive processes. A further refinement to the model is the incorporation of a different profile for the heliospheric current sheet. This profile is defined by its latitudinal extent given by Kota and Jokipii (1983), as opposed to the profile given by Jokipii and Thomas (1981). An extensive investigation into current sheet related matters is launched, illustrating the difference between these current sheet geometries, the associated drift velocity fields and the effect on modulation. At high levels of solar activity, such that the current sheet enters deep enough into the polar regions, the profile of Kota and Jokipii (1983) is found to significantly reduce the effective inward (outward) drifts of positively (negatively) charged particles during A > 0 polarity cycles. The analogous effect is true for A < 0 polarity cycles and the overall effect is of such an extent that the A > 0 and A < 0 solutions are found to coincide at the highest levels of solar activity to form a closed loop. This is a result that has never before been achieved without having to scale down the drift coefficient to zero at solar maximum, as was done by e.g. Ndiitwani et al. (2005). Furthermore, it is found that the drift velocity fields associated with these two current sheet profiles lead to significant differences in modulation even at such low levels of solar activity where no difference in the geometries of these profiles are yet in evidence. The model is finally applied to reproduce four observed galactic proton spectra, selected from PAMELA measurements (Adriani et al., 2013) during the atypical solar minimum of 2006 to 2009; a new proton local interstellar spectrum was employed. The results are found to be in accordance with that found by other authors and in particular Vos (2011), i.e. the diffusion was required to consistently increase from 2006 to 2009 and, in addition, the rigidity dependence below ~ 3 GV was required to change over this time so that the spectra became increasingly softer. / MSc (Space Physics), North-West University, Potchefstroom Campus, 2015

In this doctoral thesis, The Spirituality and Mysticism of Nature in the Early Franciscan Tradition, I have begun with an attempt to clarify the notions of spirituality and mysticism. The former, was seen as an approach to God embodied in outlook, practice and lifestyle, and the latter, mysticism, was defined as a felt awareness and knowledge of the presence of God. My hypothesis is that nature played a very important part in both the spirituality and mysticism of Saint Francis of Assisi, and in the spirituality of the movement he founded. In a systematic attempt to investigate my theme, I began with a study of the chief places associated with Francis. They present a kind of mirror of his soul and reveal, I believe, a good deal about his outlook and way of living. They tend to be remote and solitary places, often high in the mountains or near water, often desolate and harsh and usually beautiful, and what was later to become known as `romantic'. I turned then to the world of nature, beginning with the celestial bodies, sun, moon and the stars, and the elements of the sub-lunar world. The world of living things, fruits and flowers, animals, wild beasts and tame, fish and birds was examined. Nearly all the evidence here came from that collection of Franciscan stories and anecdotes which forms one of the great treasuries of stories in world literature. The fourth chapter was devoted to the poetry of Francis, above all to the Praises of God and The Canticle of the Creatures. After examining the circumstances of its composition, I took the stanzas one by one and examined them in the light of what they reveal of Francis spirituality and mysticism. The purpose of chapter five was to gather the fruits of my research and evaluate the hypothesis I proposed. I concluded that Francis, incorporated nature into his spirituality and mysticism in a very original way. I hold that Francis was a great nature mystic, and that his nature spirituality is still full of vigor and potential for the future. / Christian Spirituality, Church History and Missiology / (D.Th. (Christian Spirituality))

Topic This study examines the hymnic pericopes found at Revelation 4.8-11; 5.9-14; 7.10- 12; 11.15-18; 12.10-12; 15.3,4 and 19.1-8 in light of the cosmic conflict theme. It considers that this theme is a major contributor to the development of Revelation’s plot, and thus the hymnic sections are informed by, and inform the understanding of the controversy. Purpose Recognizing that the majority of critical studies give interpretative primacy to the social and political realities that existed in the Roman Empire at the time of Revelation’s composition, there is need for an examination of the storyline from the perspective of issues that are clearly of narratival importance. This study argues that the cosmic conflict is at the center of the book’s concerns, and attempts to determine the function of the hymns in relation to the ongoing controversy. Previous examinations of the hymnic sections have either considered them to be a response and/or parody to Roman liturgy, examples of God’s unquestioned sovereignty, or expressions of thematic overtones found throughout the book. While all these approaches make a contribution to a greater understanding of the hymns, the relation of the hymns to the ever-present conflict theme has not been explored. This study allows the hymnic sections to engage with the larger narrative issue as to who is truly the rightful sovereign of the universe. Conclusion This study found that a close examination of the text confirms that the cosmic conflict is the major motif in the narrative, and that it does not simply serve as a metaphor for political realities. It also concluded that the temple/throne room imagery found throughout the storyline, should have a controlling influence upon interpretation. This setting provides the backdrop for understanding the origins and issues of the controversy. Another conclusion of the study is that the only way for the controversy to be resolved is for God to reveal Himself in such a manner that the truth about Him is manifest. Finally, it was seen that the hymns do provide commentary on the conflict, by acclaiming God’s goodness and right to rule, despite the undertones of Satan’s accusations. / New Testament / D. Th. (New Testament)

<p>A search for a diffuse flux of cosmic neutrinos with energies in excess of 10¹⁴ eV was performed using two years of AMANDA-II data, collected in 2003 and 2004. A 20% evenly distributed sub-sample of experimental data was used to verify the detector description and the analysis cuts. A very good agreement between this 20% sample and the background simulations was observed. The analysis was optimised for discovery, to a relatively low price in limit setting power. The background estimate for the livetime of the examined 80% sample is 0.035 ± 68% events with an additional 41% systematical uncertainty.</p><p>The total neutrino flux needed for a 5σ discovery to be made with 50% probability was estimated to 3.4 ∙ 10^-7 <i>E</i>^-2 GeV s^-1 sr^-1 cm^-2 equally distributed over the three flavours, taking statistical and systematic uncertainties in the background expectation and the signal efficiency into account. No experimental events survived the final discriminator cut. Hence, no ultra-high energy neutrino candidates were found in the examined sample. A 90% upper limit is placed on the total ultra-high energy neutrino flux at 2.8 ∙ 10^-7 <i>E</i>^-2 GeV s^-1 sr^-1cm^-2, taking both systematical and statistical uncertainties into account. The energy range in which 90% of the simulated <i>E</i>^-2signal is contained is 2.94 ∙ 10¹⁴ eV to 1.54 ∙ 10¹⁸eV (central interval), assuming an equal distribution over the neutrino flavours at the Earth. The final acceptance is distributed as 48% electron neutrinos, 27% muon neutrinos, and 25% tau neutrinos.</p><p>A set of models for the production of neutrinos in active galactic nuclei that predict spectra deviating from <i>E</i>^-2 was excluded.</p>

While today, archival theory is permeated with postmodern ideas and philosophies, borrowing from fields as diverse as anthropology and computer science, even just a few decades ago, this was far from the case. This transition was pioneered and strongly influenced by the imaginative and thought-provoking essays of Hugh Taylor, a Canadian archivist who developed a worldview that positioned archives and archivists at centre stage. Taylor was able to do so as a result of his fascination with the works of the media theorist, Marshall McLuhan, whose ideas Taylor found directly applicable to archives and archival theory. This thesis examines the mental state of Hugh Taylor throughout his life and how this mental state shaped his revolutionary concepts, which delved into epistemology and metaphysics, placing archives at the centre of a universal network of connections. These concepts would go on to drastically change archival theory to what it is today. / October 2016

The core aim of this interdisciplinary research is to provide a critical analysis of the influence of Darwinism and Social Darwinism on a sample of modern Chinese writings. To achieve these aims, the researcher uses a range of both Chinese and English sources to explore their close affinities with Darwinism and Social Darwinism. Following this course, the research examines how Darwinian thought was introduced to the Chinese reading public in the late nineteenth century through a translation of Thomas Henry Huxley’s Evolution and Ethics by Yen Fu, and the subsequent impact of this work and Darwinian thought in general on seven literary and political figures: K'ang Yu-wei, Liang Qichao, Lu Xun, Hu Shih, Chen Duxiu, Sun Yat-sen and Mao Zedong. From an historical perspective, the Opium Wars and imperial invasions of China in the nineteenth century severely weakened the country’s political, economic, diplomatic, military, educational and cultural power. For these reasons and others, from 1840 to 1949, China experienced a tumultuous period of social and political transformation, which has eventually led to her revival in the twenty-first century. It will be seen that each of the literary figures examined here used evolutionary thought to justify revolution at various points on China’s long march to modernity. Progressive Darwinian ideas sharply contrasted with the old Confucian values upheld within Chinese communities. Nevertheless, the faults and weaknesses of Qing China awakened many pioneering revolutionaries who sought to reverse the status quo by initiating a series of radical reforms and revolutionary movements. Many within the Chinese intellectual elite looked to the tide of change and progress coming from the West, which they hoped might replace the recent historical stagnation and Confucian dogma embedded in Chinese culture and society. In this vein, many of these pioneering revolutionaries set about driving the historical transformation of China by selecting, translating and interpreting Darwinian ideas in their own writings. From Yen Fu in the nineteenth century to Mao Zedong in the twentieth century, evolutionary thought went hand in hand with China’s modernization.

Nous avons développé une méthode pour analyse isotopique de Yb et Er, deux terres rares aux propriétés chimiques identiques et aux températures de condensation différentes, avec comme objectifs (1) de déterminer la variabilité isotopique de ces éléments dans les processus pétrologiques terrestres, et (2) de comparer leurs compositions isotopiques dans les chondrites, la Terre et la Lune afin de déterminer le rôle potentiel de la condensation à haute température à partir de vapeurs qui a suivi l’impact géant à l’origine de la formation de la Lune. Les résultats obtenus montrent une plus grande variabilité des fractionnements isotopiques de Yb par rapport à ceux d’Er. Deux effets contribuent à cette différence : un effet oxydo-réducteur et un effet de température. La corrélation positive obtenue entre la composition isotopique en Yb, et le rapport La/Yb dans les échantillons terrestres, peut être interprétée par la présence d’une faible fraction d’ Yb(2+), Yb étant majoritairement présent sous la forme Yb(3+). La kimberlite (liquide magmatique formé par un faible taux de fusion partielle) est enrichie en isotopes lourds et les grenats, résidus de fusion partielle, sont isotopiquement légers, tandis que les basaltes de ride ou d’îles ont des compositions isotopiques intermédiaires.La composition isotopique en Yb de la Lune est enrichie en isotopes légers par rapport à celle de la Terre et des chondrites. Dans le disque proto-lunaire, les frictions entre les phases fondues et gazeuses favorisent la migration des premiers condensats très réfractaires et enrichis en isotopes lourds vers la Terre, et celle de la vapeur enrichie en isotopes légers, vers l’extérieur, au-delà de la limite de Roche à partir de laquelle la Lune s’accrète. Ceci est un nouvel argument en faveur de la condensation de la Lune à partir de vapeur générée par un impact géant. La mesure de la composition isotopique d’Er dans les échantillons lunaires reflète pour la première fois la capture par 167Er des neutrons produits par interaction du rayonnement cosmique galactique avec la surface lunaire. L’apport de Er aux systèmes communément utilisés pour déterminer le spectre d’énergie des neutrons d’un matériau peut permettre de couvrir une gamme énergétique plus large et de disposer ainsi d’un proxy plus complet pour l’étude des histoires des irradiations des matériaux planétaires. / Er and Yb are two refractory rare-earth elements that have overall similar crystallochemical properties but differ in their temperatures of condensation from the nebular gas. We developed an analytical protocol for the measurement of Er and Yb isotope compositions 1) to establish their isotopic variability in terrestrial magmatic processes 2) to compare their isotopic composition in chondrites, Earth and Moon in order to study fractionation during the high temperature condensation of vapor formed by the giant impact that generated the Moon. The range of mass-dependent isotope fractionation obtained is larger for Yb than Er isotopes. Two effects contribute to the difference between Er and Yb : a redox effect and a temperature effect.First, for terrestrial rocks, the presence of a small fraction of Yb(2+) together with the most common Yb(3+) is inferred from the positive corre- lation between δYb and the La/Yb ratio. Yb(3+) fractionates favorably into tighter bonds and, at the same time, is much more compatible than Yb(2+). Small-degree melts (kimberlite) tend to be enriched in the heavy Yb isotopes, whereas the opposite is true for residual garnets. Second, the stronger volatility of Yb with respect to Er is demonstrated by the apparent deficit of heavy Yb isotopes in the Moon with respect to the Earth, chondrites, and eucrites. Separation of vapor from melt and of heavy from light isotopes is first expected during the adiabatic expansion of the initial vapor plume. Subsequently, friction between melt and gas tends to further enrich the Moon feeding zone in silicate vapor to compensate the inward migration of melt out of the pre-lunar disk. The lighter isotope composition of Yb in lunar samples provides new evidence that the Moon formed by condensation of silicate vapor in the aftermath of the giant lunar impact.Erbium isotope ratios in lunar samples reflect for the first time the capture by 167Er of secondary neutrons produced by interactions of galactic cosmic rays with the lunar surface. The cross section of 167Er for neutron capture being particularly strong and its first resonance standing out at energies poorly covered by other nuclides, 167Er anomalies may help refine the knowledge of the neutron energy spectrum on the Moon and other planetary bodies.

The aim of this thesis is to compare similar cosmogonic narratives in Indian and Chinese culture. The most important elements are the motives of the egg and the giant/god who is formed from it. Comparative method consist of the comparison of the meanings and interpretations of the motives of these two elements, depending on the expectations and character of the source of this mythological narrative. Final findings are, that the importance of both motives in the texts and their participation in the process of creation of the world change chronologically, due to changes in religious, philosophical and social preferences. In Indian cultural environment in the begining, the vague motive of the egg slowly emerges and becomes a single creative element, gaining importance and continues to the stage where it reaches the same level of importance as the cosmic being. The primordial being on the other hand, loses its function of cosmic matter and passes it to the egg. The being itself then plays an active role rather than an object. China, for its religious scepticism suppressed motive of the egg until it was completely removed from texts. The primary role is played by the cosmic giant whose role is not focused on the creation of the world itself but the desintegration of the giants body, representing fission...