326 research outputs found
Superthermal electron processes in the upper atmosphere of Uranus: Aurora and electroglow
Strong ultraviolet emissions from the upper atmosphere of Uranus suggest that both auroral and electroglow phenomena are of significant aeronomical consequences in the structure of the upper atmosphere. Combined modeling and data analysis were performed to determine the effect of electroglow and auroral phenomena on the global heat and atomic hydrogen budgets in the Uranus upper atmosphere. The results indicate that the auroral and electroglow heat sources are not adequate to explain the high exospheric temperature observed at Uranus, but that the atomic hydrogen supplied by these processes is more than sufficient to explain the observations. The various superthermal electron distributions modeled have significantly different efficiencies for the various processes such as UV emission, heating, ionization, and atomic hydrogen production, and produce quite different H2 band spectra. However, additional information on the UV spectra and global parameters is needed before modeling can be used to distinguish between the possible mechanisms for electroglow
NG7538 IRS1 N: modeling a circumstellar maser disk
We present an edge-on Keplerian disk model to explain the main component of
the 12.2 and 6.7 GHz methanol maser emission detected toward NGC7538-IRS1 N.
The brightness distribution and spectrum of the line of bright masers are
successfully modeled with high amplification of background radio continuum
emission along velocity coherent paths through a maser disk. The bend seen in
the position-velocity diagram is a characteristic signature of differentially
rotating disks. For a central mass of 30 solar masses, suggested by other
observations, our model fixes the masing disk to have inner and outer radii of
about 270 AU and 750 AU.Comment: To appear in The Proceedings of the 2004 European Workshop: "Dense
Molecular Gas around Protostars and in Galatic Nuclei", Eds. Y. Hagiwara,
W.A. Baan, H.J. van Langevelde, 2004, a special issue of ApSS, Kluwe
The moral economy of security
In this article we draw upon our recent research into security consumption to answer two questions: first, under what conditions do people experience the buying and selling of security goods and services as morally troubling? Second, what are the theoretical implications of understanding private security as, in certain respects, tainted trade? We begin by drawing on two bodies of work on morality and markets (one found in political theory, the other in cultural sociology) in order to develop what we call a moral economy of security. We then use this theoretical resource to conduct an anatomy of the modes of ambivalence and unease that the trade in security generates. Three categories organize the analysis: blocked exchange; corrosive exchange; and intangible exchange. In conclusion, we briefly spell out the wider significance of our claim that the buying and selling of security is a morally charged and contested practice of governance
The geo-constitution: Understanding the intersection of geography and political institutions
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.This paper draws on existing work in the discipline of human geography and cognate fields in order
to develop the concept of the ‘geo-constitution’. This concept aims to: (1) highlight the importance
of intersections between geography and political institutions in the constitution of government; (2)
consider the path-dependent development of political institutions and their impact on statecraft and
citizenship; (3) explore the implications of this for political reform. The paper provides an overview
of current thinking in political geography and applies the concept of the geo-constitution to the
example of devolution and localism in the United Kingdom
Ordering theories: typologies and conceptual frameworks for sociotechnical change
What theories or concepts are most useful at explaining socio technical change? How can – or cannot – these be integrated? To provide an answer, this study presents the results from 35 semi-structured research interviews with social science experts who also shared more than two hundred articles, reports and books on the topic of the acceptance, adoption, use, or diffusion of technology. This material led to the identification of 96 theories and conceptual approaches spanning 22 identified disciplines. The article begins by explaining its research terms and methods before honing in on a combination of fourteen theories deemed most relevant and useful by the material. These are: Sociotechnical Transitions, Social Practice Theory, Discourse Theory, Domestication Theory, Large Technical Systems, Social Construction of Technology, Sociotechnical Imaginaries, Actor-Network Theory, Social Justice Theory, Sociology of Expectations, Sustainable Development, Values Beliefs Norms Theory, Lifestyle Theory, and the Unified Theory of Acceptance and Use of Technology. It then positions these theories in terms of two distinct typologies. Theories can be placed into five general categories of being centered on agency, structure, meaning, relations or norms. They can also be classified based on their assumptions and goals rooted in functionalism, interpretivism, humanism or conflict. The article lays out tips for research methodology before concluding with insights about technology itself, analytical processes associated with technology, and the framing and communication of results. An interdisciplinary theoretical and conceptual inventory has much to offer students, analysts and scholars wanting to study technological change and society
Managing the climate commons at the nexus of ecology, behaviour and economics
Sustainably managing coupled ecological–economic systems requires not only an understanding of the environmental factors that affect them, but also knowledge of the interactions and feedback cycles that operate between resource dynamics and activities attributable to human intervention. The socioeconomic dynamics, in turn, call for an investigation of the behavioural drivers behind human action. We argue that a multidisciplinary approach is needed in order to tackle the increasingly pressing and intertwined environmental challenges faced by modern societies. Academic contributions to climate change policy have been constrained by methodological and terminological differences, so we discuss how programmes aimed at cross-disciplinary education and involvement in governance may help to unlock scholars' potential to propose new solutions
IPCC reasons for concern regarding climate change risks
The reasons for concern framework communicates scientific understanding about risks in relation to varying levels of climate change. The framework, now a cornerstone of the IPCC assessments, aggregates global risks into five categories as a function of global mean temperature change. We review the framework's conceptual basis and the risk judgments made in the most recent IPCC report, confirming those judgments in most cases in the light of more recent literature and identifying their limitations. We point to extensions of the framework that offer complementary climate change metrics to global mean temperature change and better account for possible changes in social and ecological system vulnerability. Further research should systematically evaluate risks under alternative scenarios of future climatic and societal conditions
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