Photoinitiated oxidative addition of CF3I to gold(I) and facile aryl-CF3 reductive elimination.

Herein we report the mechanism of oxidative addition of CF3I to Au(I), and remarkably fast Caryl-CF3 bond reductive elimination from Au(III) cations. CF3I undergoes a fast, formal oxidative addition to R3PAuR (R = Cy, R = 3,5-F2-C6H4, 4-F-C6H4, C6H5, 4-Me-C6H4, 4-MeO-C6H4, Me; R = Ph, R = 4-F-C6H4, 4-Me-C6H4). When R = aryl, complexes of the type R3PAu(aryl)(CF3)I can be isolated and characterized. Mechanistic studies suggest that near-ultraviolet light (λmax = 313 nm) photoinitiates a radical chain reaction by exciting CF3I. Complexes supported by PPh3 undergo reversible phosphine dissociation at 110 °C to generate a three-coordinate intermediate that undergoes slow reductive elimination. These processes are quantitative and heavily favor Caryl-I reductive elimination over Caryl-CF3 reductive elimination. Silver-mediated halide abstraction from all complexes of the type R3PAu(aryl)(CF3)I results in quantitative formation of Ar-CF3 in less than 1 min at temperatures as low as -10 °C

Survey of Ophthalmologists-in-Training in Eastern, Central and Southern Africa - Survey data and questionnaire

Survey questionnaire and data produced as part of a study to analyse current surgical training practice and experience of ophthalmologists in Eastern, Central and Southern Africa for the purpose of informing future planning of training. It is associated with a research paper titled "Survey of ophthalmologists-in-training in Eastern, Central and Southern Africa

The Intellectual Fallout from World War I

Many books link World War II to postmodernism, but few link World War I in the same way. The author here explores the intellectual fallout from World War I as the context of the roots of post-modernism. His limited purpose in this paper is to explore one of many possible links between the unanticipated carnage of World War I, through existentialism, to the attack on meaning in history posed by postmodernism. The postmodern drive towards individual isolation and autonomy has a corrosive political impact on our world, as it does on individual well being. One of the internal inconsistencies that appeared as the Modernist paradigm matured was the political idea of the ultimate value of the nation-state. That idea challenged the fabric of political and economic life on which the modern world was built. World War I was a series of confrontations among five empires: the British Empire, which survived the war, but only for a generation, and the German, Austro-Hungarian, Russian, and Ottoman Empires, which did not survive it. They all collapsed by the end of the war. The nation-state idea revealed its dark side: each and every nationality, no matter how small, deserved to be an independent state with its own story, identity, and right of self-determination. Today we are watching this process of disintegration continue: Spain, Italy, Great Britain, Yugoslavia, Czechoslovakia, Syria, Iraq, Libya, Nigeria, China, Russia, and others reveal either effect or possibility of fracture. World War I provided the stage on which the inner tensions inherent in modernism were released. The splintering continues, and the paradigm will collapse completely. Someday, postmodernism will also shatter, undermined by inherent contradictions within and the radical emphasis on individual autonomy. In the meantime, people of faith have a grand opportunity to provide an alternative to the meaninglessness that our age has accepted in place of the false certainties of modernism. If anything, postmodernism is more susceptible to authentic Christian witness and solidarity that Modernism was. The future is brighter than we sometimes think

Evaluation of Football Helmet Impact Performance from 1880s to 2020s

Undergraduate Applie

The influence of the hydrologic cycle on the extent of sea ice with climatic implications

Multi-temporal satellite images, field observations, and field measurements were used to investigate the mechanisms by which sea ice melts offshore from the Mackenzie River delta. Advanced Very High Resolution Radiometer (AVHRR) satellite data recorded in 1986 were analyzed. The satellite data were geometrically corrected and radiometrically calibrated so that albedo and temperature values could be extracted. The investigation revealed that sea ice melted approximately 2 weeks earlier offshore from the Mackenzie River delta than along coasts where river discharge is minimal or non-existent. There is significant intra-delta variability in the timing and patterns of ice melt. An estimation of energy flux indicates that 30 percent more of the visible wavelength energy and 25 percent more of the near-infrared wavelength energy is absorbed by water offshore of the delta compared to coastal areas with minimal river discharge. The analysis also revealed that the removal of sea ice involves the following: over-ice-flooding along the coast offshore from river delta channels; under-ice flow of 'warm' river water; melting and calving of the fast ice; and, the formation of a bight in the pack ice edge. Two stages in the melting of sea ice were identified: (1) an early stage where heat is supplied to overflows largely by solar radiation, and (2) a later stage where heat is supplied by river discharge in addition to solar radiation. A simple thermodynamic model of the thaw process in the fast ice zone was developed and parameterized based on events recorded by the satellite images. The model treats river discharge as the source of sensible heat at the base of the ice cover. The results of a series of sensitivity tests to assess the influence of river discharge on the near shore ice are presented

The Last of the True: The Kid\u27s Place In Cormac McCarthy\u27s Blood Meridian

In this study I examine the relationship of “the kid” and “the judge” in Cormac McCarthy’s Blood Meridian Or The Evening Redness in the West (1985), specifically, how and why the kid resists Judge Holden’s overbearing existential philosophy. In my introduction I set the stage for Judge Holden’s imperial philosophy and practice through a brief explanation of his character, both historical and fictional, and the novel’s success because of his tyrannical grandeur. I then juxtapose the recalcitrant character of the kid against this megalomaniac to set up the rest of the examination of their relationship. In my chapter on Judge Holden’s universe, I outline his worldview through close readings of his endless lectures and soliloquies, and argue that his ultimate concern is for control. Chapter Two lays out the particulars of how the kid resists this control through various strategies that directly oppose the judge’s controlling mechanisms. Finally, my third chapter examines the implications of the kid’s resistance and how it affects the judge on the narrative level, and how it affects readers’ ability to approach this juggernaut anew. Maintaining a focus on the kid, as the judge does throughout the novel, despite both the novel’s noticeable focal shift off of him, and his reluctance to engage on a dialogic level, argues for a new reading of the kid. Though he kills and raids with the rest of them, the judge’s inability to extend his usual control signals something morally unique in the kid. Not enough to save his life, but enough to lend some heroic credence to the mysterious figure of the novel’s epilogue