2,823 research outputs found
Prediction of Smoothed Sunspot Number Using Dynamic Relations Between the Sun and Planets
Dynamic parameters of sun and planet interaction for predicting sunspot
Proximity-Aware Calculation of Cable Series Impedance for Systems of Solid and Hollow Conductors
Wide-band cable models for the prediction of electromagnetic transients in
power systems require the accurate calculation of the cable series impedance as
function of frequency. A surface current approach was recently proposed for
systems of round solid conductors, with inclusion of skin and proximity
effects. In this paper we extend the approach to include tubular conductors,
allowing to model realistic cables with tubular sheaths, armors and pipes. We
also include the effect of a lossy ground. A noteworthy feature of the proposed
technique is the accurate prediction of proximity effects, which can be of
major importance in three-phase, pipe type, and closely-packed single-core
cables. The new approach is highly efficient compared to finite elements. In
the case of a cross-bonded cable system featuring three phase conductors and
three screens, the proposed technique computes the required 120 frequency
samples in only six seconds of CPU time.Comment: Update: This paper has been accepted for publication in the IEEE
Transactions on Power Delivery. DOI: 10.1109/TPWRD.2014.233099
Szego coordinates, quadrature domains, and double quadrature domains
We define Szego coordinates on a finitely connected smoothly bounded planar
domain which effect a holomorphic change of coordinates on the domain that can
be as close to the identity as desired and which convert the domain to a
quadrature domain with respect to boundary arc length. When these Szego
coordinates coincide with Bergman coordinates, the result is a double
quadrature domain with respect to both area and arc length. We enumerate a host
of interesting and useful properties that such double quadrature domains
possess, and we show that such domains are in fact dense in the realm of
bounded finitely connected domains with smooth boundaries.Comment: 19 page
Indo-European loanwords and exchange in Bronze Age Central and East Asia
Loanword analysis is a unique contribution of historical linguistics to our understanding of prehistoric cultural interfaces. As language reflects the lives of its speakers, the substantiation of loanwords draws on the composite evidence from linguistic as well as auxiliary data from archaeology and genetics through triangulation. The Bronze Age of Central Asia is in principle linguistically mute, but a host of recent independent observations that tie languages, cultures, and genetics together in various ways invites a comprehensive reassessment of six highly diagnostic loanwords (âsevenâ, âname/fameâ, âsister-in-lawâ, âhoneyâ, âmetalâ, and âhorseâ), that are associated with the Bronze Age. Moreover, they are shared between Indo-European, Uralic, Turkic, and sometimes Old Chinese. The successful identification of the interfaces for these loanwords can help settle longstanding debates on languages, migrations, and the items themselves. Each item is analyzed using the comparative method with reference to the archaeological record to assess the plausibility of a transfer. I argue that the six items can be dated to have entered Central and East Asian languages from immigrant Indo-European languages spoken in the Afanasievo and Andronovo cultures, including a novel source for the âhorseâ in Old Chinese.Introduction - Uralic - Turkic and wider Transeurasian - Chinese and wider Sino-Tibetan - Indo-European languages in ancient Central Asia - Indirectly documented languages - The early archaeological cultures: Afanasievo and Okunevo - Structure of the argument Method - The comparative method - Loanwords - Data triangulation - Methodological protocol Data and results - Seven - Name and fame - Honey Discussion - Seven - Name-fame - Sister-in-law - Honey - Gold, copper, bronze - Horse (and chariot) - The origin of the Tocharian languages Conclusio
Phase field modelling of surfactants in multi-phase flow
A diffuse interface model for surfactants in multi-phase flow with three or
more fluids is derived. A system of Cahn-Hilliard equations is coupled with a
Navier-Stokes system and an advection-diffusion equation for the surfactant
ensuring thermodynamic consistency. By an asymptotic analysis the model can be
related to a moving boundary problem in the sharp interface limit, which is
derived from first principles. Results from numerical simulations support the
theoretical findings. The main novelties are centred around the conditions in
the triple junctions where three fluids meet. Specifically the case of local
chemical equilibrium with respect to the surfactant is considered, which allows
for interfacial surfactant flow through the triple junctions
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