18,051 research outputs found
The use of tethers for payload orbital transfer. Continuation of investigation of electrodynamic stabilization and control of long orbiting tethers, volume 2
The SKYHOOK program was used to do simulations of two cases of the use of the tether for payload orbital transfer. The transport of a payload along the tether from a heavy lower platform to an upper launching platform is considered. A numerical example of the Shuttle launching a payload using an orbital tether facility is described
Renormalization Group and Grand Unification with 331 Models
By making a renormalization group analysis we explore the possibility of
having a 331 model as the only intermediate gauge group between the standard
model and the scale of unification of the three coupling constants. We shall
assume that there is no necessarily a group of grand unification at the scale
of convergence of the couplings. With this scenario, different 331 models and
their corresponding supersymmetric versions are considered, and we find the
versions that allow the symmetry breaking described above. Besides, the allowed
interval for the 331 symmetry breaking scale, and the behavior of the running
coupling constants are obtained. It worths saying that some of the
supersymmetric scenarios could be natural frameworks for split supersymmetry.
Finally, we look for possible 331 models with a simple group at the grand
unification scale, that could fit the symmetry breaking scheme described above.Comment: 18 pages. 3 figures. Some results reinterpreted, a new section and
references added. Version to appear in International Journal of Modern
Physics
Coulomb displacement energies, energy differenced and neutron skins
A Fock space representation of the monopole part of the Coulomb potential is
presented. Quantum effects show through a small orbital term in . Once
it is averaged out, the classical electrostatic energy emerges as an
essentially exact expression, which makes it possible to eliminate the
Nolen-Schiffer anomaly, and to estimate neutron skins and the evolution of
radii along yrast states of mirror nuclei. The energy differences of the latter
are quantitatively reproduced by the monopole term and a schematic multipole
one.Comment: 4 pages, 3 figures, Revte
Bank lending to small businesses in Latin America : does Bank origin matter?
In recent years foreign bank participation has increased tremendously in Latin America. Some observers argue that foreign bank entry will benefit Latin American banking systems by reducing the volatility of loans and deposits and increasing efficiency. Others are concerned that foreign banks might choose to extend credit only to certain customers, leaving some sectors-such as small businesses-unserved. The authors examine this issue. Using bank-level data for Argentina, Chile, Colombia, and Peru during the mid-1990s, they empirically investigate whether bank origin affects the share and growth rate of bank lending to small businesses. They find that although foreign banks generally lent less to small businesses (as share of total lending) than private domestic banks, the difference is due primarily to the behavior of small foreign banks. The difference was considerably smaller for large and medium-sized banks. And in Chile and Colombia, large foreign banks might actually lend slightly more (as share of total lending) than large domestic banks.Financial Intermediation,Banks&Banking Reform,Financial Crisis Management&Restructuring,Payment Systems&Infrastructure,Economic Theory&Research,Banks&Banking Reform,Financial Intermediation,Financial Crisis Management&Restructuring,Economic Theory&Research,Banking Law
Muyurina y el presente profundo: poéticas andino-amazónicas
Este libro es una trenza entre investigación, creación y oralidad. Su
origen se remonta a la canción “Memorias muertas” del álbum “Remembranza
Huamanguina” que el Trío Ayacucho diera a conocer en 1974, y que fuera hallada
hace poco en una calle de Lima. La primera estrofa de la canción se convirtió
en motivo poético o sonido subyacente que prestó el nombre al performance
MUYUNA (A place to move), hecho por jóvenes estudiantes y artistas de Cornell
University en 1986. Este mismo motivo dio origen al poema “Muyurina” de Fredy
A. Roncalla, palabra que en este libro/kipu funciona como lugar de encuentro de
varias voces y direcciones
Uranio / Uranium
Difícil es imaginar un elemento que la gran mayoría
nunca ha visto o tocado. Sin embargo, dicho elemento
mineral de la Madre Naturaleza se encuentra conectado
a la energía que consume nuestra civilización, a sus
comodidades y a algunas de las historias más terribles y
dolorosas del siglo XX y XXI.
La poesía de Juan Sánchez hace el Uranio visible no
como un objeto de estudio científico, sino mostrándonos
cómo es su relación con el ser humano. El poema “Uranio”
de este libro es un entretejido de historias, sentires
y hechos sobre la minería extractiva en los sagrados
territorios de las comunidades nativo americanas del
suroeste de los Estados Unidos. En este libro también hemos querido hacer visible una
conexión transpacífica, pues la industria extractiva del
uranio está ligada al desarrollo de la energía nuclear y las
armas nucleares (que utilizan el uranio como una de sus
materias primas). [...
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