3,512 research outputs found
The NIST compilation of ionization potentials revisited (I): From He-like to Xe-like ions
The National Institute of Standards and Technology (NIST) database on
ionization potentials for neutral atoms and ions is examined. For each
isoelectronic sequence, we construct a regularized perturbative series that
exactly matches the large- and regions. Comparison of the
NIST data with this series allows the identification of problematic values in
the reported data.Comment: 19 pages, 43 figure
Predicting signatures of anisotropic resonance energy transfer in dye-functionalized nanoparticles
Resonance energy transfer (RET) is an inherently anisotropic process. Even
the simplest, well-known F\"orster theory, based on the transition
dipole-dipole coupling, implicitly incorporates the anisotropic character of
RET. In this theoretical work, we study possible signatures of the fundamental
anisotropic character of RET in hybrid nanomaterials composed of a
semiconductor nanoparticle (NP) decorated with molecular dyes. In particular,
by means of a realistic kinetic model, we show that the analysis of the dye
photoluminescence difference for orthogonal input polarizations reveals the
anisotropic character of the dye-NP RET which arises from the intrinsic
anisotropy of the NP lattice. In a prototypical core/shell wurtzite CdSe/ZnS NP
functionalized with cyanine dyes (Cy3B), this difference is predicted to be as
large as 75\% and it is strongly dependent in amplitude and sign on the dye-NP
distance. We account for all the possible RET processes within the system,
together with competing decay pathways in the separate segments. In addition,
we show that the anisotropic signature of RET is persistent up to a large
number of dyes per NP.Comment: 9 pages, 5 figures. Supplementary information available at
http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra22433d/unauth#!divAbstrac
Shape sensitivity analysis for structural problems with non‐linear material behaviour
This paper describes some considerations around the analytical structural shape sensitivity analysis when the structural behaviour is computed using the finite element method with a non‐linear constitutive material model. Depending on the type of non‐linear behaviour two different approaches are proposed. First, a new direct (non‐incremental) formulation is proposed for material models characterized by the fact that the stresses at any time t can be expressed in terms of the strains at the same time t and, in some cases, the strains at a specific past time tu (tu<t). This is the case of elasticity (linear as well as non‐linear), perfect plasticity and damage models. Second, a more classical incremental approach is proposed for general plasticity cases. A special strategy is also proposed for material models with strain softening. The quality and reliability of the proposed approaches are assessed through their application in different examples
Activation of effector immune cells promotes tumor stochastic extinction: A homotopy analysis approach
In this article we provide homotopy solutions of a cancer nonlinear model
describing the dynamics of tumor cells in interaction with healthy and effector
immune cells. We apply a semi-analytic technique for solving strongly nonlinear
systems - the Step Homotopy Analysis Method (SHAM). This algorithm, based on a
modification of the standard homotopy analysis method (HAM), allows to obtain a
one-parameter family of explicit series solutions. By using the homotopy
solutions, we first investigate the dynamical effect of the activation of the
effector immune cells in the deterministic dynamics, showing that an increased
activation makes the system to enter into chaotic dynamics via a
period-doubling bifurcation scenario. Then, by adding demographic stochasticity
into the homotopy solutions, we show, as a difference from the deterministic
dynamics, that an increased activation of the immune cells facilitates cancer
clearance involving tumor cells extinction and healthy cells persistence. Our
results highlight the importance of therapies activating the effector immune
cells at early stages of cancer progression
The railway heritage in Mexico and its role in the configuration of industrial and cultural landscapes
The construction of the railways in Mexico was an event of national importance, not only for its role in the economic history, but for their contribution in shaping cultural landscapes of industrial character. The railway system made many cultural exchanges possible in various regions, setting an important natural, social and cultural environment. In recent years most of the vast industrial railway heritage has become obsolete and unused, and has suffered rapid and alarming deterioration. Jalisco is located in the west of the country and has the largest lake in Mexico. Two trunk railway lines and many branches communicating the haciendas and towns passed through the region. Some of these routes have been abandoned. The projects, “Vía verde del Mariachi” and “Vía verde de Chapala” seek to recognize the importance of the cultural industrial landscapes created by the railroad in this part of México. Aims to recover the memory of the railway routes and the design of a network of more than 200 kilometers of non motorized routes along 11 municipalities have included projects to rescue and conserve the tangible and intangible heritage of these regions. These constitute integral conservation projects focused on recognizing the value of the natural, cultural and industrial landscapes linked to the railway history in Mexico.ITESO, A.C
Editorial: In Memoriam Julio Hurtado Llopis (1960-2014)
Editorial: In Memoriam Julio Hurtado Llopis (1960-2014
Enhanced light-harvesting of protein-pigment complexes assisted by a quantum dot antenna
We predict the enhanced light harvesting of a protein-pigment complex when
assembled to a quantum dot (QD) antenna. Our prototypical nanoassembly setup is
composed of a Fenna-Mattews-Olson system hosting 8 Bacteriochlorophyll (BChl) a
dyes, and a near-infrared emitting CdSeTe/ZnS alloy-core/shell
nanocrystal. BChl a has two wide windows of poor absorption in the green and
orange-red bands, precisely where most of the sunlight energy lies. The
selected QD is able to collect sunlight efficiently in a broader band and
funnel its energy by a (non-radiative) F\"orster resonance energy transfer
mechanism to the dyes embedded in the protein. By virtue of the coupling
between the QD and the dyes, the nanoassembly absorption is dramatically
improved in the poor absorption window of the BChl a.Comment: 5 pages, 3 figures, presented in the NANOFIM 2018 conference in
Mexico Cit
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