711 research outputs found
BIOFUELS, AGRICULTURE AND CLIMATE CHANGE
No full textIn the context of ever-increasing petroleum prices combined with concerns about climate change, timing of adoption and rate of diffusion of land-based fuels and backstop technologies for transportation use are examined in this paper. A global model of land allocation joined with a Hotelling model has been developed. Using this framework, effects of climate and energy policies on world agricultural and energy markets have been explored. Further, their regional impacts are also analyzed. Whereas mandatory blending bio-fuels have substantial effects on world food prices and do not succeed in curbing down carbon emissions fluxes, carbon targets are expected to speed up date of adoption of backstop technologies. Then, sensitivity scenarios with regards to technological parameters reveal that higher is the rate of technological change, earlier backstop technologies are adopted and lower is the stock of carbon accumulated into the atmosphere. Finally, interplay between land-based fuels and deforestation has been studied. Results show that land-based fuels production speeds up world deforestation and causes substantial carbon emissions due to conversion of forests into agricultural lands.Ricardian rents, land use, biofuels, Resource /Energy Economics and Policy,
The brightness of the CO Cameron bands in the martian discrete aurora: A study based on revised cross sections
No full textpeer reviewedWe analyze the consequences of the new laboratory measurements of the emissions cross sections of the Cameron bands excited by electron impact on CO2 and CO in the Mars aurora. We use Monte Carlo simulations to investigate the importance of these changes and their dependence on the initial electron energy. The Mars Climate Database (MCD) is used as an input for the temperature and neutral density profiles. Auroral density profiles of O2+, CO+2 and electrons in the aurora are calculated for a range of precipitating electron energies. The
total nadir brightness of the Cameron bands is reduced by a factor of 4.5 at 150 eV and 5.1 at 700 eV relative to calculations made with the previously recommended cross section. The relative contributions to the production of the Cameron bands by electron collisions with CO2 and CO are examined. It varies with the CO/CO2 density ratio near the emission peak that depends on the neutral model and season. Dissociative recombination of CO+2
ions provides a contribution between 10% and 45% at the altitude of maximum production of the a 3Π state. The efficiency of the nadir brightness of the Cameron bands is 2.5–3.6 kilorayleighs per incident electron energy flux of 1 mW m-2, with a small dependence on the initial electron energy. Model simulations predict that the intensity ratio of the Cameron bands to the CO+2 UV doublet (UVD) depends on the electron initial energy. It varies
from 2.0 at 500 eV to 5.3 at 50 eV, for both Ls = 90° and 225°
Portfolio of recorded performances and exegesis: Messiaen’s musical language for the jazz pianist - an exploration through performance.
No full textMoving beyond Gunther Schuller’s Third Stream amalgamation of classical and jazz, this study explores whether the musical language of Olivier Messiaen can make a valid contribution to jazz piano performance. Initially, my project sought to answer such questions as: What elements of the musical language of Messiaen already exist in the jazz vocabulary? Am I able to extend this further? What are the timbral structures and pianistic effects within Messiaen’s musical language? What will be the most effective application of Messiaen’s musical language to jazz piano performance? Endeavouring to answer the final question led me to consider such aspects as whether the project should be limited to quoting Messiaen motifs, arranging Messiaen melodies, replacing jazz harmonic structures on standards with examples from Messiaen’s musical language or whether it would be better to approach the research conceptually. The work of Hubert Nuss provided encouraging reassurance that this was not an impossible task. In order to articulate this conception, the initial challenge was to decide how the classical and jazz worlds might meet in a ‘Messiaen’ technique. The approach adopted was similar to that used for undergraduate jazz study, namely, immersion in the piano scores and recordings of Messiaen’s music as well as by live performances. This was followed by the development and assessment of a contrived approach when specific techniques, such as tonal colourings or harmonic structures, were developed through prepared exercises and consciously included in my performance. It was then compared with an intuitive approach when no such precise parameters were established. This submission consists of CD recordings of two public recitals and an exegesis. It documents the development of this Messiaen technique and discusses its application in my performances. It also demonstrates the ways that Messiaen’s musical language can be used within jazz piano performance to provide a colour that distinguishes jazz piano performance in a competitive field.Thesis (M.Mus.) -- University of Adelaide, Elder Conservatorium of Music, 201
Fenomenología husserliana e inteligencia artificial en Hubert L. Dreyfus
No full textTrabajo de Fin de Máster en Investigación en Lógica y Filosofía de la Ciencia, curso 2013-2014.[ES]Nuestra hipótesis es que el proyecto tecnológico de la inteligencia artificial y la fenomenología de cariz husserliano son muy próximos en la obra de Dreyfus, dando un mayor espacio a la influencia de Follesdal, filósofo de origen noruego que determinará la imagen, para algunos sesgada, que nuestro autor tiene de Husserl. La segunda hipótesis es que los logros empíricos, descriptivos y técnicos de la inteligencia artificial han ayudado a clarificar cuestiones fenomenológicas. La tercera hipótesis, corporalizada, es que el trabajo de Dreyfus ha podido ser un acicate para que este proyecto tecnológico despejase incógnitas, prejuicios y dogmatismos[EN]Our hypothesis is that the technological project of artificial intelligence and the Husserlian-type phenomenology are very close in the work of Hubert L. Dreyfus, giving more space to the influence of Follesdal, philosopher of Norwegian origin who will determine the image, for some biased, that our author has of Husserl. The second hypothesis is that the empirical, descriptive and technical achievements of artificial intelligence have helped to clarify phenomenological issues. The third hypothesis, under the influence of embodiment, the work of Dreyfuss has been an incentive for the technological project to clear up unknowns, prejudices and dogmatisms
An analysis of the Dennis Hubert and S. S. Mincey cases to illustrate changing trends toward mob violence and the fostering of interracial cooperation in Georgia, 1930, 1988
No full textThe primary purpose of this research is to illustrate changing trends in white Georgians' attitudes toward lynching and mob violence in Georgia during 1930. The Dennis Hubert and S. S. Mincey cases and their results will be used as examples to reflect such trends as well as illustrate interracial cooperation among the races. During 1930, Georgia witnessed at least six terrible acts of mob violence in the form of lynchings and murder. Also this number constituted the highest number in comparison to other states that year. The Dennis Hubert and S. S. Mincey cases were different from any other lynching which occurred in Georgia in that white Georgians denounced these murders and made a considerable attempt to apprehend the guilty parties as well as aid the families of these Negro victims. The primary sources for this research were derived from the Commission on Interracial Cooperation (CIC) collection and the Association of Southern Women for the Prevention of Lynching (ASWPL) papers located at the Atlanta University Center Robert W. Woodruff Library. This collection included the newspaper clippings collected by the CIC, letters, minutes, sermons and unpublished material used in pursuing this research
Ionization-induced star formation - IV. Triggering in bound clusters
No full textWe present a detailed study of star formation occurring in bound star-forming clouds under the influence of internal ionizing feedback from massive stars across a spectrum of cloud properties. We infer which objects are triggered by comparing our feedback simulations with control simulations in which no feedback was present. We find that feedback always results in a lower star formation efficiency and usually but not always results in a larger number of stars or clusters. Cluster mass functions are not strongly affected by feedback, but stellar mass functions are biased towards lower masses. Ionization also affects the geometrical distribution of stars in ways that are robust against projection effects, but may make the stellar associations more or less subclustered depending on the background cloud environment. We observe a prominent pillar in one simulation which is the remains of an accretion flow feeding the central ionizing cluster of its host cloud and suggest that this may be a general formation mechanism for pillars such as those observed in M16. We find that the association of stars with structures in the gas such as shells or pillars is a good but by no means foolproof indication that those stars have been triggered and we conclude overall that it is very difficult to deduce which objects have been induced to form and which formed spontaneously simply from observing the system at a single time.Peer reviewe
Dead reckonings: disease and the study of nature in Portuguese Asia and the Atlantic, 1450-1650
No full textThe following dissertation traces the convergence of science, culture, and politics in Portugal’s most important tropical colonies—Goa, India and Bahia, Brazil. It shows how contradictions between an idealized colonial order and the exigencies of settlement
patterned debates over the practice of medicine and, in the process, redefined scientific authority, credibility, and the study of nature. This story began in the Atlantic, where the unexpected virulence of certain fevers along the West African coast challenged European ideas about the causes of disease. To survive, the Portuguese turned to indigenous medical specialists, often women. With colonization in Asia and the Americas, this practice intensified and grew more controversial. Hindu and Muslim physicians in Goa as
well as Amerindian and, later, African-descended healers in Bahia mediated Portuguese access to local flora and its curative uses. The two zones of colonization differed, however, in fundamental ways. The comparative dimension of this project helps clarify these differences so as to explain the emergence of particular kinds of medical interaction within each colonial setting. At the same, I argue that colonial medicine—as it took shape throughout Portugal’s empire—was always built upon a fundamental opposition that was inherent in the project of colonization itself: Portuguese communities became dependent on forms knowledge-making that they simultaneously sought to displace. At issue was
the authority (and therefore power) that women and non-Christian peoples wielded in the production and verification of truth claims about the natural world. Hence in the colonies, the intertwined disciplines of medicine and natural history confronted tensions and
ambiguities that distinguished them from their metropolitan counterparts. And this in turn fostered distinct ways of assembling intellectual communities, asserting claims to truth, representing both in print, and defending that work in the face of suspicion and
accusation from colonial governors and Inquisition officials alike.Ph. D.Includes bibliographical referencesby Hubert Glenn Cagle II
MAVEN‐IUVS observations of the CO2+ UV doublet and CO Cameron bands in the Martian thermosphere: Aeronomy, seasonal and latitudinal distribution.
No full textpeer reviewedWe analyze two Martian years of dayglow measurements of the CO Cameron bands and the CO2+ ultraviolet doublet (UVD) at 298-299 nm with the Imaging UltraViolet Spectrograph on board the Maven orbiter. We show that the altitude and the brightness of the two emissions peaks are strongly correlated, although data were collected over a wide range of latitudes and seasons. veraged limb profiles are presented and compared with numerical simulations based on updated calculations of the production of the CO (a3Π) and the CO2+ (B 2Σ) states. The model simulations use the solar flux directly measured on board MAVEN with the Extreme Ultraviolet Monitor (EUVM) and the neutral densities provided by the Mars Climate Database (MCD) version 5.3, adapted to
the conditions of the observations. We show that the altitude and the shape of the sample limb profiles are well reproduced using the MCD neutral atmosphere. The simulated peak intensities of the CO2+ UVD and Cameron bands are in good agreement considering the uncertainties on the excitation cross sections and the calibration of the IUVS and EUVM instruments. No significant adjustment of the electron impact cross section on CO2 to produce the a3Π state is needed. Seasonal-latitudinal maps of the Cameron and UVD peak altitude observed during two Martian years show variations as large as 23 km. Model simulations of the amplitude of these changes are in fair agreement with the observations except during the southern summer dust period (Ls =
270°-320°) when the calculated rise of the dayglow layer is underestimated
A survey of the attitudes of Atlanta University graduate students toward the costs and operations of revolving credit, 1968
No full textSouvenirs de l' Aide-Major Lamare-Picquot (1807-1814) publiés et annotés par Hubert Pernot avec un appendice sur l' Académie fondée par les Français à Corfou.
No full textPreface: editor]Appendix: 4Introduction: author]Dedication:Content description: Detailed contentsPagination: PP9+256PVolumes: 1Text Genre:Pros
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