4,882 research outputs found
ECONOMIC EFFECTS OF MINNESOTA PEATLAND DEVELOPMENT
Existing peatland development and future uses for peat are described and evaluated in this report. Scenarios for future development of the study area peat industry are described in terms of employment, earnings, capital investment, and value of production. Forecasts of the potential impacts of peatland development on regional industry production, employment, earnings, and population are presented. These impacts are determined by using SIMLAB, an acronym for a regional socio-economic computer model developed at the University of Minnesota for quantitative analysis of the direct, indirect and induced socio-economic effects of events like peatland development.Land Economics/Use,
ECONOMIC EFFECTS OF COPPER-NICKEL DEVELOPMENT IN NORTHEAST MINNESOTA
Computer simulations of industry gross output, employment and earnings changes associated with alternative copper-nickel development scenarios are presented in this report. The direct and indirect economic effects of seven development scenarios are projected for a mining impact Study Area in St. Louis County, Minnesota.Community/Rural/Urban Development, Resource /Energy Economics and Policy,
Bridging k- and q- Space in the Cuprates: Comparing ARPES and STM Results
A critical comparison is made between the ARPES-derived spectral function and
STM studies of Friedel-like oscillations in Bi_2Sr_2CaCu_2O_{8+delta} (Bi2212).
The data can be made approximately consistent, provided that (a) the elastic
scattering seen in ARPES is predominantly small-angle scattering and (b) the
`peak' feature seen in ARPES is really a dispersive `bright spot', smeared into
a line by limited energy resolution; these are the `bright spots' which control
the quasiparticle interferences. However, there is no indication of bilayer
splitting in the STM data.Comment: 6 eps figures, revte
USERS' GUIDE TO THE MINNESOTA REGIONAL DEVELOPMENT SIMULATION LABORATORY
This manual is a users' guide to the Minnesota Regional Development Simulation Laboratory, called SIMLAB.Community/Rural/Urban Development,
Sound propagation in density wave conductors and the effect of long-range Coulomb interaction
We study theoretically the sound propagation in charge- and spin-density
waves in the hydrodynamic regime. First, making use of the method of comoving
frame, we construct the stress tensor appropriate for quasi-one dimensional
systems within tight-binding approximation. Taking into account the screening
effect of the long-range Coulomb interaction, we find that the increase of the
sound velocity below the critical temperature is about two orders of magnitude
less for longitudinal sound than for transverse one. It is shown that only the
transverse sound wave with displacement vector parallel to the chain direction
couples to the phason of the density wave, therefore we expect significant
electromechanical effect only in this case.Comment: revtex, 14 pages (in preprint form), submitted to PR
Nonlinear current response of one- and two-band superconductors
We have calculated the nonlinear current of a number of single band s-wave
electron-phonon superconductors. Among issues considered were those of
dimensionality, strong electron-phonon coupling, impurities, and comparison
with BCS. For the case of two bands, particular attention is paid to the role
of anisotropy, the integration effects of the off-diagonal electron-phonon
interaction, as well as inter- and intraband impurities. For the specific case
of MgB2, we present results based on the known microscopic parameters of band
theory.Comment: 10 pages, 6 figure
The upper critical field of filamentary Nb3Sn conductors
We have examined the upper critical field of a large and representative set
of present multi-filamentary Nb3Sn wires and one bulk sample over a temperature
range from 1.4 K up to the zero field critical temperature. Since all present
wires use a solid-state diffusion reaction to form the A15 layers,
inhomogeneities with respect to Sn content are inevitable, in contrast to some
previously studied homogeneous samples. Our study emphasizes the effects that
these inevitable inhomogeneities have on the field-temperature phase boundary.
The property inhomogeneities are extracted from field-dependent resistive
transitions which we find broaden with increasing inhomogeneity. The upper
90-99 % of the transitions clearly separates alloyed and binary wires but a
pure, Cu-free binary bulk sample also exhibits a zero temperature critical
field that is comparable to the ternary wires. The highest mu0Hc2 detected in
the ternary wires are remarkably constant: The highest zero temperature upper
critical fields and zero field critical temperatures fall within 29.5 +/- 0.3 T
and 17.8 +/- 0.3 K respectively, independent of the wire layout. The complete
field-temperature phase boundary can be described very well with the relatively
simple Maki-DeGennes model using a two parameter fit, independent of
composition, strain state, sample layout or applied critical state criterion.Comment: Accepted Journal of Applied Physics Few changes to shorten document,
replaced eq. 7-
Magneto-Hydrodynamics of Population III Star Formation
Jet driving and fragmentation process in collapsing primordial cloud are
studied using three-dimensional MHD nested grid simulations. Starting from a
rotating magnetized spherical cloud with the number density of n=10^3 cm^-3, we
follow the evolution of the cloud up to the stellar density n=10^22 cm^-3. We
calculate 36 models parameterizing the initial magnetic and rotational energies
(\gamma_0, \beta_0). In the collapsing primordial clouds, the cloud evolutions
are characterized by the ratio of the initial rotational to magnetic energy,
\gamma_0/\beta_0. The Lorentz force significantly affects the cloud evolution
when \gamma_0 > \beta_0, while the centrifugal force is more dominant than the
Lorentz force when \beta_0 > \gamma_0. When the cloud rotates rapidly with
angular velocity of \Omega_0 > 10^-17 (n/10^3 cm^-3)^2/3 s^-1 and \beta_0 >
\gamma_0, fragmentation occurs before the protostar is formed, but no jet
appears after the protostar formation. On the other hand, a strong jet appears
after the protostar formation without fragmentation when the initial cloud has
the magnetic field of B_0 > 10^-9 (n/10^3 cm^-3)^2/3 G and \gamma_0 > \beta_0.
Our results indicate that proto-Population III stars frequently show
fragmentation and protostellar jet. Population III stars are therefore born as
binary or multiple stellar systems, and they can drive strong jets, which
disturb the interstellar medium significantly, as well as in the present-day
star formation, and thus they may induce the formation of next generation
stars.Comment: 37 pages, 10 figures, Submitted to ApJ, For high resolution figures,
see http://astro3.sci.hokudai.ac.jp/~machida/astro-ph.pd
- …