14,923 research outputs found
Dissipation in Mesoscopic Superconductors with Ac Magnetic Fields
The response of mesoscopic superconductors to an ac magnetic field is
investigated both experimentally and with numerical simulations. We study small
square samples with dimensions of the order of the penetration depth. We obtain
the ac susceptibitity at microwave frequencies as a
function of the dc magnetic field . We find that the dissipation, given
by , has a non monotonous behavior in mesoscopic samples. In the
numerical simulations we obtain that the dissipation increases before the
penetration of vortices and then it decreases abruptly after vortices have
entered the sample. This is verified experimentally, where we find that
has strong oscillations as a function of in small squares of
Pb.Comment: 4 pages, 2 figure
Transportation noise pollution - Control and abatement
Control and abatement of transportation noise pollutio
Industrial noise control: Some case histories, volume 1
A collection of solutions to industrial noise problems is presented. Each problem is described in simple terms, with noise measurements where available, and the solution is given, often with explanatory figures. Where the solution rationale is not obvious, an explanatory paragraph is usually appended. As a preface to these solutions, a short exposition is provided of some of the guiding concepts used by noise control engineers in devising their solutions
Power in the Multinational Corporation in Industry Equilibrium
Recent theories of the multinational corporation introduce the property rights model of the firm and examine whether to integrate our outsource firm activities locally or to a foreign country. This paper focus instead on the internal organization of the multinational corporation by examining the power allocation between headquarters and subsidiaries. We provide a framework to analyse the interaction between the decision to serve the local market by exporting or FDI, market acces and the optimal mode of organization of the multinational corporation. We find that subsidiary managers are given most autonomy in their decision how to run the firm at intermediate levels of local competition. We then provide comparative statics for changes in fixed FDI entry costs and trade costs, information technology, the number of local competitors, and in the size of the local market
Threshold and non-linear behavior of lasers of and V - configurations
Dynamic properties of closed three level laser systems are investigated. Two
schemes of pumping - and V - are considered. It is shown that the
non-linear behavior of the photon number as a function of pump both near and
far above threshold is crucially different for these two configurations. In
particular, it is found that in the high pump regime laser can turn off in a
phase-transition-like manner in both and V schemes.Comment: 9 pages, 5 figure
Two-point functions for SU(3) Polyakov Loops near T_c
We discuss the behavior of two point functions for Polyakov loops in a SU(3)
gauge theory about the critical temperature, T_c. From a Z(3) model, in mean
field theory we obtain a prediction for the ratio of masses at T_c, extracted
from correlation functions for the imaginary and real parts of the Polyakov
loop. This ratio is m_i/m_r = 3 if the potential only includes terms up to
quartic order in the Polyakov loop; its value changes as pentic and hexatic
interactions become important. The Polyakov Loop Model then predicts how
m_i/m_r changes above T_c.Comment: 5 pages, no figures; reference adde
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