3,960,455 research outputs found
Process for applying a protective coating for salt bath brazing Patent
Application techniques for protecting materials during salt bath brazin
Pauli blocking and medium effects in nucleon knockout reactions
We study medium modifications of the nucleon-nucleon (NN) cross sections and
their influence on the nucleon knockout reactions. Using the eikonal
approximation, we compare the results obtained with free NN cross sections with
those obtained with a purely geometrical treatment of Pauli-blocking and with
NN obtained with more elaborated Dirac-Bruecker methods. The medium effects are
parametrized in terms of the baryon density. We focus on symmetric nuclear
matter, although the geometrical Pauli-blocking allows for the treatment of
asymmetric nuclear matter. It is shown that medium effects can change the
nucleon knockout cross sections and momentum distributions up to 10% in the
energy range E=50-300 MeV/nucleon. The effect is more evident in reactions
involving halo nuclei.Comment: 10 pages, 9 figures, accepted for publication in Physics Review
Protective coating for salt-bath brazing
Ceramic coating, consisting of graphite, enameler's clay, and algin binder, applied to materials prior to salt bath brazing facilitates brazing process and results in superior joints. Alternate coating materials and their various proportions are given
Weak values and the quantum phase space
We address the issue of how to properly treat, and in a more general setting,
the concept of a weak value of a weak measurement in quantum mechanics. We show
that for this purpose, one must take in account the effects of the measuring
process on the entire phase space of the measuring system. By using coherent
states, we go a step further than Jozsa in a recent paper, and we present an
example where the result of the measurement is symmetrical in the position and
momentum observables and seems to be much better suited for quantum optical
implementation.Comment: 07 pages, accepted for PR
Quark masses in QCD: a progress report
Recent progress on QCD sum rule determinations of the light and heavy quark
masses is reported. In the light quark sector a major breakthrough has been
made recently in connection with the historical systematic uncertainties due to
a lack of experimental information on the pseudoscalar resonance spectral
functions. It is now possible to suppress this contribution to the 1% level by
using suitable integration kernels in Finite Energy QCD sum rules. This allows
to determine the up-, down-, and strange-quark masses with an unprecedented
precision of some 8-10%. Further reduction of this uncertainty will be possible
with improved accuracy in the strong coupling, now the main source of error. In
the heavy quark sector, the availability of experimental data in the vector
channel, and the use of suitable multipurpose integration kernels allows to
increase the accuracy of the charm- and bottom-quarks masses to the 1% level.Comment: Invited review paper to be published in Modern Physics Letters
Market response to external events and interventions in spherical minority games
We solve the dynamics of large spherical Minority Games (MG) in the presence
of non-negligible time dependent external contributions to the overall market
bid. The latter represent the actions of market regulators, or other major
natural or political events that impact on the market. In contrast to
non-spherical MGs, the spherical formulation allows one to derive closed
dynamical order parameter equations in explicit form and work out the market's
response to such events fully analytically. We focus on a comparison between
the response to stationary versus oscillating market interventions, and reveal
profound and partially unexpected differences in terms of transition lines and
the volatility.Comment: 14 pages LaTeX, 5 (composite) postscript figures, submitted to
Journal of Physics
Meadow enriched ACP process algebras
We introduce the notion of an ACP process algebra. The models of the axiom
system ACP are the origin of this notion. ACP process algebras have to do with
processes in which no data are involved. We also introduce the notion of a
meadow enriched ACP process algebra, which is a simple generalization of the
notion of an ACP process algebra to processes in which data are involved. In
meadow enriched ACP process algebras, the mathematical structure for data is a
meadow.Comment: 8 pages; correction in Table
An interface group for process components
We take a process component as a pair of an interface and a behaviour. We
study the composition of interacting process components in the setting of
process algebra. We formalize the interfaces of interacting process components
by means of an interface group. An interesting feature of the interface group
is that it allows for distinguishing between expectations and promises in
interfaces of process components. This distinction comes into play in case
components with both client and server behaviour are involved.Comment: 26 pages; section on non-associativity of component composition
added, examples adde
- …