9,208,683 research outputs found

    Partially-erupting prominences: a comparison between observations and model-predicted observables

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    <p><b>Aims:</b> We investigate several partially-erupting prominences to study their relationship with other CME-associated phenomena and compare these observations with observables predicted by a model of partially-expelled-flux-ropes (Gibson & Fan 2006a, ApJ, 637, L65; 2006b, J. Geophys. Res., 111, 12103).</p> <p><b>Methods:</b> We studied 6 selected events with partially-erupting prominences using multi-wavelength observations recorded by the Extreme-ultraviolet Imaging Telescope (EIT), Transition Region and Coronal Explorer (TRACE), Mauna Loa Solar Observatory (MLSO), Big Bear Solar Observatory (BBSO), and Soft X-ray Telescope (SXT). The observational features associated with partially-erupting prominences were then compared with the predicted observables from the model.</p> <p><b>Results:</b> The partially-expelled-flux-rope (PEFR) model can explain the partial eruption of these prominences, and in addition predicts a variety of other CME-related observables that provide evidence of internal reconnection during eruption. We find that all of the partially-erupting prominences studied in this paper exhibit indirect evidence of internal reconnection. Moreover, all cases showed evidence of at least one observable unique to the PEFR model, e.g., dimmings external to the source region and/or a soft X-ray cusp overlying a reformed sigmoid.</p> <p><b>Conclusions:</b> The PEFR model provides a plausible mechanism to explain the observed evolution of partially-erupting-prominence-associated CMEs in our study.</p&gt

    Eruption of magnetic flux ropes during flux emergence

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    Aims: We investigate the formation of flux ropes in a flux emergence region and their rise into the outer atmosphere of the Sun. Methods: We perform 3D numerical experiments solving the time-dependent and resistive MHD equations. Results: A sub-photospheric twisted flux tube rises from the solar interior and expands into the corona. A flux rope is formed within the expanding field, due to shearing and reconnection of field lines at low atmospheric heights. If the tube emerges into a non-magnetized atmosphere, the flux rope rises, but remains confined inside the expanding magnetized volume. On the contrary, if the expanding tube is allowed to reconnect with a preexisting coronal field, the flux rope experiences a full eruption with a rise profile which is in qualitative agreement with erupting filaments and Coronal Mass Ejections

    Application of Market Models to Network Equilibrium Problems

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    We present a general two-side market model with divisible commodities and price functions of participants. A general existence result on unbounded sets is obtained from its variational inequality re-formulation. We describe an extension of the network flow equilibrium problem with elastic demands and a new equilibrium type model for resource allocation problems in wireless communication networks, which appear to be particular cases of the general market model. This enables us to obtain new existence results for these models as some adjustments of that for the market model. Under certain additional conditions the general market model can be reduced to a decomposable optimization problem where the goal function is the sum of two functions and one of them is convex separable, whereas the feasible set is the corresponding Cartesian product. We discuss some versions of the partial linearization method, which can be applied to these network equilibrium problems.Comment: 18 pages, 3 table

    Auctor in Fabula: Umberto Eco and the Intentio of Foucault\u27s Pendulum

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    Umberto Eco’s 1988 novel Foucault’s Pendulum weaves together a wide range of philosophical and literary threads. Many of these threads find their other ends in Eco’s nonfiction works, which focus primarily on the question of interpretation and the source of meaning. The novel, which follows three distinctly overinterpretive characters as they descend into ruin, has been read by some as a retraction or parody of Eco’s own position. However, if Foucault’s Pendulum is indeed polemical, it must be taken as an argument against the mindset which Eco has termed the “hermetic”. Through an examination of his larger theoretical body, including its themes and intellectual heritage, it will be seen that Eco preserves his philosophical consistency across his fictive and non-fictive work

    Between Physicality and Symbolism: Kyiv as a Contested Territory in Russian and Ukrainian Émigré Letters, 1920–1939

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    The paper deals with visions of Kyiv in the writings of Russian and Ukrainian émigré writers during the interwar period. The city became a focal point of intensive intellectual debate whose participants regarded Kyiv not only as a place of a recent battleground but also as a sacral place and a highly symbolic image. Within the methodological framework of ethnic symbolism, this study attempts to explain how this physical/symbolic dichotomy was used to reinforce continuing claims for historical origin and cultural heritage, thus serving the contemporary purpose of national identity and political legitimacy. It also deploys the concept of displacement as a complex process of negotiation between homeland and hostland within an émigré community — whose sense of loss and identity crisis creates additional impetus, though in different forms, for exploiting historical narratives

    Transit-Oriented Brownfield Redevelopment

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    Best Poster Award, Department of Economics, Fall 2019Brownfield properties are properties wherein future use is inhibited either by the presence or perceived presence of harmful pollutants. As a consequence, these properties are difficult to develop and prospective developers require sufficient positive incentives in order to be attracted to these projects. To investigate the extent to which public transit can act as an amenity for these properties, this study examines the relationship between commuter rail transit stations and brownfield property redevelopment rates in Mecklenburg County, NC using both a linear probability model and a propensity score matching approach. The analysis results indicate that there is indeed a relationship between light rail and brownfield redevelopment, but the direction of the relationship depends on the analysis technique used.No embargoAcademic Major: Economic
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