19,689 research outputs found
Santo Toribio: The Rise of a Saint
Santo Toribio (1900-28) was canonized by the Roman Catholic Church in 2000 as a martyr of Mexico\u27s bloody Cristero Rebellion. He enjoyed a modest local following for decades after the Rebellion as many of the other Cristero martyr-saints did. However, around the time of his canonization, a new identity began to emerge different from that of martyr; he became the patron saint of immigration. For believers, Santo Toribio helps mitigate the criminal nature of this act by showing God\u27s approval and blessing. He places the pain and social distortion of Border crossing in Roman Catholic contexts of holiness and divine intervention. This thesis begins to catalog and analyze the nature of Santo Toribio\u27s unofficial patronage
Steady-state conduction in self-similar billiards
The self-similar Lorentz billiard channel is a spatially extended
deterministic dynamical system which consists of an infinite one-dimensional
sequence of cells whose sizes increase monotonically according to their
indices. This special geometry induces a nonequilibrium stationary state with
particles flowing steadily from the small to the large scales. The
corresponding invariant measure has fractal properties reflected by the
phase-space contraction rate of the dynamics restricted to a single cell with
appropriate boundary conditions. In the near-equilibrium limit, we find
numerical agreement between this quantity and the entropy production rate as
specified by thermodynamics
Non-equilibrium Lorentz gas on a curved space
The periodic Lorentz gas with external field and iso-kinetic thermostat is
equivalent, by conformal transformation, to a billiard with expanding
phase-space and slightly distorted scatterers, for which the trajectories are
straight lines. A further time rescaling allows to keep the speed constant in
that new geometry. In the hyperbolic regime, the stationary state of this
billiard is characterized by a phase-space contraction rate, equal to that of
the iso-kinetic Lorentz gas. In contrast to the iso-kinetic Lorentz gas where
phase-space contraction occurs in the bulk, the phase-space contraction rate
here takes place at the periodic boundaries
Spontaneous Breaking of Translational Invariance in One-Dimensional Stationary States on a Ring
We consider a model in which positive and negative particles diffuse in an
asymmetric, CP-invariant way on a ring. The positive particles hop clockwise,
the negative counterclockwise and oppositely-charged adjacent particles may
swap positions. Monte-Carlo simulations and analytic calculations suggest that
the model has three phases; a "pure" phase in which one has three pinned blocks
of only positive, negative particles and vacancies, and in which translational
invariance is spontaneously broken, a "mixed" phase with a non-vanishing
current in which the three blocks are positive, negative and neutral, and a
disordered phase without blocks.Comment: 7 pages, LaTeX, needs epsf.st
Atomistic study on the pressure dependence of the melting point of NdFe12
We investigated, using molecular dynamics, how pressure affects the melting point of the recently theorised and epitaxially grown structure NdFe12. We modified Morse potentials using experimental constants and a genetic algorithm code, before running two-phase solid-liquid coexistence simulations of NdFe12 at various temperatures and pressures. The refitting of the Morse potentials allowed us to significantly improve the accuracy in predicting the melting temperature of the constituent elements
Analytic structure of solutions to multiconfiguration equations
We study the regularity at the positions of the (fixed) nuclei of solutions
to (non-relativistic) multiconfiguration equations (including Hartree--Fock) of
Coulomb systems. We prove the following: Let {phi_1,...,phi_M} be any solution
to the rank--M multiconfiguration equations for a molecule with L fixed nuclei
at R_1,...,R_L in R^3. Then, for any j in {1,...,M} and k in {1,...,L}, there
exists a neighbourhood U_{j,k} in R^3 of R_k, and functions phi^{(1)}_{j,k},
phi^{(2)}_{j,k}, real analytic in U_{j,k}, such that phi_j(x) =
phi^{(1)}_{j,k}(x) + |x - R_k| phi^{(2)}_{j,k}(x), x in U_{j,k} A similar
result holds for the corresponding electron density. The proof uses the
Kustaanheimo--Stiefel transformation, as applied earlier by the authors to the
study of the eigenfunctions of the Schr"odinger operator of atoms and molecules
near two-particle coalescence points.Comment: 15 page
The Chemical Compositions of the Type II Cepheids -- The BL Her and W Vir Variables
Abundance analyses from high-resolution optical spectra are presented for 19
Type II Cepheids in the Galactic field. The sample includes both short-period
(BL Her) and long-period (W Vir) stars. This is the first extensive abundance
analysis of these variables. The C, N, and O abundances with similar spreads
for the BL Her and W Vir show evidence for an atmosphere contaminated with
-process and CN-cycling products. A notable anomaly of the BL Her
stars is an overabundance of Na by a factor of about five relative to their
presumed initial abundances. This overabundance is not seen in the W Vir stars.
The abundance anomalies running from mild to extreme in W Vir stars but not
seen in the BL Her stars are attributed to dust-gas separation that provides an
atmosphere deficient in elements of high condensation temperature, notably Al,
Ca, Sc, Ti, and -process elements. Such anomalies have previously been seen
among RV Tau stars which represent a long-period extension of the variability
enjoyed by the Type II Cepheids. Comments are offered on how the contrasting
abundance anomalies of BL Her and W Vir stars may be explained in terms of the
stars' evolution from the blue horizontal branch.Comment: 41 pages including 11 figures and 4 tables; Accepted for publication
in Ap
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