792 research outputs found
Choosing the Best Direction of Printing for Additive Manufacturing Process in Medical Applications Using a New Geometric Complexity Model Based on Part CAD Data
Additive manufacturing processes is now experiencing significant growth and is at the origin of intense research activity (optimization of topology, biomedical applications, etc.). One of the characteristics of this method is that the geometric complexity is free. The complexity of a CAD model is also a field of research. The basic idea is that the complexity of a component has implications in design and especially in manufacturing. Indeed, industrial competitiveness in the mechanical field generated the need to produce increasingly complex systems and parts (in terms of geometry, topology ...). Part deposition orientation is also very important factor of additive manufacturing as it effects build time, support structure, dimensional accuracy, surface finish and cost of the part. A number of layered manufacturing process specific parameters and constraints have to be considered while deciding the part deposition orientation. Determination of an optimal part deposition orientation is a difficult and time consuming task as one has to trade-off among various contradicting objectives like part surface finish and build time. This paper describes and compares various attempts made to determine part deposition orientation of orthoses using geometric complexity model and part CAD information. (c) Springer Nature Switzerland AG 2019
QGP flow fluctuations and the characteristics of higher moments
The dynamical development of expanding Quark-gluon Plasma (QGP) flow is
studied in a 3+1D fluid dynamical model with a globally symmetric, initial
condition. We minimize fluctuations arising from complex dynamical processes at
finite impact parameters and from fluctuating random initial conditions to have
a conservative fluid dynamical background estimate for the statistical
distributions of the thermodynamical parameters. We also avoid a phase
transition in the equation of state, and we let the matter supercool during the
expansion.
Then central Pb+Pb collisions at TeV are studied in an
almost perfect fluid dynamical model, with azimuthally symmetric initial state
generated in a dynamical flux-tube model. The general development of
thermodynamical extensives are also shown for lower energies.
We observe considerable deviations from a thermal equilibrium source as a
consequence of the fluid dynamical expansion arising from a least fluctuating
initial state
Extending the Real-Time Maude Semantics of Ptolemy to Hierarchical DE Models
This paper extends our Real-Time Maude formalization of the semantics of flat
Ptolemy II discrete-event (DE) models to hierarchical models, including modal
models. This is a challenging task that requires combining synchronous
fixed-point computations with hierarchical structure. The synthesis of a
Real-Time Maude verification model from a Ptolemy II DE model, and the formal
verification of the synthesized model in Real-Time Maude, have been integrated
into Ptolemy II, enabling a model-engineering process that combines the
convenience of Ptolemy II DE modeling and simulation with formal verification
in Real-Time Maude.Comment: In Proceedings RTRTS 2010, arXiv:1009.398
Flux dependent MeV self-ion- induced effects on Au nanostructures: Dramatic mass transport and nano-silicide formation
We report a direct observation of dramatic mass transport due to 1.5 MeV Au2+
ion impact on isolated Au nanostructures of an average size 7.6 nm and a height
6.9 nm that are deposited on Si (111) substrate under high flux (3.2x10^10 to
6.3x10^12 ions cm-2 s-1) conditions. The mass transport from nanostructures
found to extend up to a distance of about 60 nm into the substrate, much beyond
their size. This forward mass transport is compared with the recoil
implantation profiles using SRIM simulation. The observed anomalies with theory
and simulations are discussed. At a given energy, the incident flux plays a
major role in mass transport and its re-distribution. The mass transport is
explained on the basis of thermal effects and creation of rapid diffusion paths
at nano-scale regime during the course of ion irradiation. The unusual mass
transport is found to be associated with the formation of gold silicide
nanoalloys at sub-surfaces. The complexity of the ion-nanostructure interaction
process has been discussed with a direct observation of melting (in the form of
spherical fragments on the surface) phenomena. The transmission electron
microscopy, scanning transmission electron microscopy and Rutherford
backscattering spectroscopy methods have been used.Comment: 16 pages, 6 Figure
Encephalitis temporally associated with live attenuated Japanese encephalitis vaccine: four case reports
QCD equation of state at nonzero chemical potential: continuum results with physical quark masses at order mu^2
We determine the equation of state of QCD for nonzero chemical potentials via
a Taylor expansion of the pressure. The results are obtained for N_f=2+1
flavors of quarks with physical masses, on various lattice spacings. We present
results for the pressure, interaction measure, energy density, entropy density,
and the speed of sound for small chemical potentials. At low temperatures we
compare our results with the Hadron Resonance Gas model. We also express our
observables along trajectories of constant entropy over particle number. A
simple parameterization is given (the Matlab/Octave script parameterization.m,
submitted to the arXiv along with the paper), which can be used to reconstruct
the observables as functions of T and mu, or as functions of T and S/N.Comment: 14 pages, 15 figures, version accepted for publication in JHE
Observation of CR Anisotropy with ARGO-YBJ
The measurement of the anisotropies of cosmic ray arrival direction provides
important informations on the propagation mechanisms and on the identification
of their sources. In this paper we report the observation of anisotropy regions
at different angular scales. In particular, the observation of a possible
anisotropy on scales between 10 and 30
suggests the presence of unknown features of the magnetic fields the charged
cosmic rays propagate through, as well as potential contributions of nearby
sources to the total flux of cosmic rays. Evidence of new weaker few-degree
excesses throughout the sky region R.A. is
reported for the first time.Comment: Talk given at 12th TAUP Conference 2011, 5-9 September 2011, Munich,
German
Ordered Mesostructured CdS Nanowire Arrays with Rectifying Properties
Highly ordered mesoporous CdS nanowire arrays were synthesized by using mesoporous silica as hard template and cadmium xanthate (CdR2) as a single precursor. Upon etching silica, mesoporous CdS nanowire arrays were produced with a yield as high as 93 wt%. The nanowire arrays were characterized by XRD, N2adsorption, TEM, and SEM. The results show that the CdS products replicated from the mesoporous silica SBA-15 hard template possess highly ordered hexagonal mesostructure and fiber-like morphology, analogous to the mother template. The current–voltage characteristics of CdS nanoarrays are strongly nonlinear and asymmetrical, showing rectifying diode-like behavior
Study of Exclusive Radiative B Meson Decays
We have investigated exclusive, radiative B meson decays to charmless mesons
(\rho, \omega, \phi, K^*(892), K^*_2(1430)) in 9.7\times 10^6 BBbar decays
accumulated with the CLEO detector. The B -> K^*(892)\gamma branching fractions
are determined to be Br(B^0 -> K^{*0}(892)\gamma) = (4.55 +0.72-0.68
+-0.34)\times 10^-5 and Br(B^+ -> K^{*+}(892)\gamma) = (3.76 +0.89-0.83
+-0.28)\times 10^-5. We have searched for CP asymmetry in B -> K^*(892)\gamma
decays and measure Acp = +0.08 +-0.13 +-0.03. We also report the first
observation of the decay B -> K^*_2(1430)\gamma with a branching fraction of
(1.66 +0.59-0.53 +-0.13)\times 10^-5 and determine $Br(B ->
K^*_2(1430)\gamma)/Br(B -> K^*(892)\gamma) = 0.39 +0.15-0.13 consistent with
only one of two available theoretical models. No significant evidence for the
decays B -> \rho\gamma and B^0 -> \omega\gamma is found and we limit Br(B ->
(\rho/\omega)\gamma)/Br(B -> K^{*}(892)\gamma) < 0.32 at 90% CL. We also find
no evidence for the exotic decay B^0 -> \phi\gamma.Comment: 12 pages, 3 figures, submitted to Phys. Rev. Letter
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