5,287 research outputs found
Extending Continuum Models for Atom Probe Simulation
This work describes extensions to existing level-set algorithms developed for
application within the field of Atom Probe Tomography (APT). We present a new
simulation tool for the simulation of 3D tomographic volumes, using advanced
level set methods. By combining narrow-band, B-Tree and particle-tracing
approaches from level-set methods, we demonstrate a practical tool for
simulating shape changes to APT samples under applied electrostatic fields, in
three dimensions. This work builds upon our previous studies by allowing for
non-axially symmetric solutions, with minimal loss in computational speed,
whilst retaining numerical accuracy
An Introduction to Community Detection in Multi-layered Social Network
Social communities extraction and their dynamics are one of the most
important problems in today's social network analysis. During last few years,
many researchers have proposed their own methods for group discovery in social
networks. However, almost none of them have noticed that modern social networks
are much more complex than few years ago. Due to vast amount of different data
about various user activities available in IT systems, it is possible to
distinguish the new class of social networks called multi-layered social
network. For that reason, the new approach to community detection in the
multi-layered social network, which utilizes multi-layered edge clustering
coefficient is proposed in the paper.Comment: M.D. Lytras et al. (Eds.): WSKS 2011, CCIS 278, pp. 185-190, 201
Neuroendocrinology and resistance training in adult males
An understanding of the neuroendocrine system will assist the Strength and Conditioning coach in the design of progressive strength training programmes by allowing them to manipulate acute training variables according to hormone release profiles. For muscle hypertrophy, training programmes should utilise 3 sets of 10 repetitions at 10RM loads, with short rest periods of no longer than 1 minute. This will ensure the accumulation and maintenance of lactate and hydrogen ions, to which anabolic hormone release is correlated. For strength adaptations without
concomitant muscle hypertrophy, the training load and the length of rest periods should be increased, (>85% 1RM and >2mins respectively), and body parts should be rotated (e.g. upper body to lower body or agonist to antagonist). Finally, catabolic hormones and neurohormones significantly affect training adaptations. Therefore the strength and conditioning coach should be cognisant of the specific exercise programming and psychological interventions that manipulate their release
How model sets can be determined by their two-point and three-point correlations
We show that real model sets with real internal spaces are determined, up to
translation and changes of density zero by their two- and three-point
correlations. We also show that there exist pairs of real (even one
dimensional) aperiodic model sets with internal spaces that are products of
real spaces and finite cyclic groups whose two- and three-point correlations
are identical but which are not related by either translation or inversion of
their windows. All these examples are pure point diffractive.
Placed in the context of ergodic uniformly discrete point processes, the
result is that real point processes of model sets based on real internal
windows are determined by their second and third moments.Comment: 19 page
Impaired Glucose Metabolism among Those with and without Diagnosed Diabetes and Mortality: A Cohort Study Using Health Survey for England Data.
The extent that controlled diabetes impacts upon mortality, compared with uncontrolled diabetes, and how pre-diabetes alters mortality risk remain issues requiring clarification
Six types of functions of the Lie groups O(5) and G(2)
New families of -functions are described in the context of the compact
simple Lie groups O(5) and G(2). These functions of two real variables
generalize the common exponential functions and for each group, only one family
is currently found in the literature. All the families are fully characterized,
their most important properties are described, namely their continuous and
discrete orthogonalities and decompositions of their products.Comment: 25 pages, 13 figure
Displacement Detection with a Vibrating RF SQUID: Beating the Standard Linear Limit
We study a novel configuration for displacement detection consisting of a
nanomechanical resonator coupled to both, a radio frequency superconducting
interference device (RF SQUID) and to a superconducting stripline resonator. We
employ an adiabatic approximation and rotating wave approximation and calculate
the displacement sensitivity. We study the performance of such a displacement
detector when the stripline resonator is driven into a region of nonlinear
oscillations. In this region the system exhibits noise squeezing in the output
signal when homodyne detection is employed for readout. We show that
displacement sensitivity of the device in this region may exceed the upper
bound imposed upon the sensitivity when operating in the linear region. On the
other hand, we find that the high displacement sensitivity is accompanied by a
slowing down of the response of the system, resulting in a limited bandwidth
From solid solution to cluster formation of Fe and Cr in -Zr
To understand the mechanisms by which Fe and Cr additions increase the
corrosion rate of irradiated Zr alloys, a combination of experimental (atom
probe tomography, x-ray diffraction and thermoelectric power measurements) and
modelling (density functional theory) techniques are employed to investigate
the non-equilibrium solubility and clustering of Fe and Cr in binary Zr alloys.
Cr occupies both interstitial and substitutional sites in the {\alpha}-Zr
lattice, Fe favours interstitial sites, and a low-symmetry site that was not
previously modelled is found to be the most favourable for Fe. Lattice
expansion as a function of alloying concentration (in the dilute regime) is
strongly anisotropic for Fe additions, expanding the -axis while contracting
the -axis. Defect clusters are observed at higher solution concentrations,
which induce a smaller amount of lattice strain compared to the dilute defects.
In the presence of a Zr vacancy, all two-atom clusters are more soluble than
individual point defects and as many as four Fe or three Cr atoms could be
accommodated in a single Zr vacancy. The Zr vacancy is critical for the
increased solubility of defect clusters, the implications for irradiation
induced microstructure changes in Zr alloys are discussed.Comment: 15 pages including figure, 9 figures, 2 tables. Submitted for
publication in Acta Mater, Journal of Nuclear Materials (2015
On the effect of Ti on Oxidation Behaviour of a Polycrystalline Nickel-based Superalloy
Titanium is commonly added to nickel superalloys but has a well-documented
detrimental effect on oxidation resistance. The present work constitutes the
first atomistic-scale quantitative measurements of grain boundary and bulk
compositions in the oxide scale of a current generation polycrystalline nickel
superalloy performed through atom probe tomography. Titanium was found to be
particularly detrimental to oxide scale growth through grain boundary
diffusion
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