5,197 research outputs found
There are simple and robust refinements (almost) as good as Delaunay
A new edge-based partition for triangle meshes is presented, the Seven Triangle Quasi-Delaunay partition (7T-QD). The proposed partition joins together ideas of the Seven Triangle Longest-Edge partition (7T-LE), and the classical criteria for constructing Delaunay meshes. The new partition performs similarly compared to the Delaunay triangulation (7T-D) with the benefit of being more robust and with a cheaper cost in computation. It will be proved that in most of the cases the 7T-QD is equal to the 7T-D. In addition, numerical tests will show that the difference on the minimum angle obtained by the 7T-QD and by the 7T-D is negligible
Local refinement based on the 7-triangle longest-edge partition
The triangle longest-edge bisection constitutes an efficient scheme for refining a mesh by reducing the obtuse triangles, since the largest interior angles are subdivided. In this paper we specifically introduce a new local refinement for triangulations based on the longest-edge trisection, the 7-triangle longest-edge (7T-LE) local refinement algorithm. Each triangle to be refined is subdivided in seven sub-triangles by determining its longest edge. The conformity of the new mesh is assured by an automatic point insertion criterion using the oriented 1-skeleton graph of the triangulation and three partial division patterns
Diffusion dynamics on multiplex networks
We study the time scales associated to diffusion processes that take place on
multiplex networks, i.e. on a set of networks linked through interconnected
layers. To this end, we propose the construction of a supra-Laplacian matrix,
which consists of a dimensional lifting of the Laplacian matrix of each layer
of the multiplex network. We use perturbative analysis to reveal analytically
the structure of eigenvectors and eigenvalues of the complete network in terms
of the spectral properties of the individual layers. The spectrum of the
supra-Laplacian allows us to understand the physics of diffusion-like processes
on top of multiplex networks.Comment: 6 Pages including supplemental material. To appear in Physical Review
Letter
Use of a new ocular insert versus conventional mydriasis in cataract surgery
Background. To compare the efficacy and safety of a new ocular insert versus conventional mydriasis in cataract surgery. Methods. We selected 70 patients undergoing cataract surgery. Thirty five patients (Group 1) received instillation of mydriatic drops (tropicamide 1%, phenylephrine 10%, and cyclopentolate 1%) prior to surgery, and 35 patients (Group 2) had a Mydriasert insert (Théa Pharma) (0.28¿mg of tropicamide and 5.4¿mg of phenylephrine hydrochloride) placed in the inferior fornix. Pupil size before and after surgery, blood pressure, and heart rate were measured. Results. Before surgery, pupil diameter was ¿mm in Group 1 and in Group 2 ( ). Twenty four hours after surgery, pupil diameter was ¿mm in Group 1 and in Group 2 ( ). There were no statistically significant differences in blood pressure or heart rate between groups. Conclusions. The effect of the Mydriasert insert was similar to conventional mydriatic agents. Pupil size was restored to normal faster when using the Mydriasert insert compared with conventional mydriatic agents for pupil dilation
Model-based passive and active diagnostics strategies for diesel oxidation catalyst
[EN] This article proposes a diesel oxidation catalyst diagnostics strategy based on the exothermic process generated by exhaust gas species oxidation in the catalyst. The diagnostics strategy is designed to be applied on-board and respecting real-time electronic control unit computational limitations. Diagnostics purposes are fulfilled by means of the comparison of the passive model temperature, which represents the outlet temperature of a non-impregnated diesel oxidation catalyst, and the measurement provided by the on-board catalyst-out temperature sensor. Thus, the presented diagnostics strategy uses only two production grade temperature sensors and the measurements of air and fuel mass flows from the electronic control unit. Passive diagnostics is based on the oxidation of engine-raw emissions, whilst active diagnostics is based on the oxidation of requested post injected fuel. Post-injection strategy is also discussed for active diagnosis. Then, the diagnostics strategy is able to discern whether the diesel oxidation catalyst is able to oxidise or not. (C) 2016 Elsevier Ltd. All rights reserved.This research has been partially financed by the Spanish Ministerio de Economia y Competitividad, through project TRA2013-40853-R 'Desarrollo de nuevas tecnicas de limitacion de la perdida de presion en DPFs para reducir las emisiones y el consumo de los motores diesel (PRELIMIT)'.Guardiola, C.; Plá Moreno, B.; Piqueras, P.; Mora-Pérez, J.; Lefebvre, D. (2017). Model-based passive and active diagnostics strategies for diesel oxidation catalyst. Applied Thermal Engineering. 110:962-971. https://doi.org/10.1016/j.applthermaleng.2016.08.207S96297111
Threading Through Macrocycles Enhances the Performance of Carbon Nanotubes as Polymer Fillers
In this work we study the reinforcement of polymers by mechanically
interlocked derivatives of single-walled carbon nanotubes (SWNTs). We compare
the mechanical properties of fibers made of polymers and of composites with
pristine single-walled carbon nanotubes (SWNTs), mechanically interlocked
derivatives of SWNTs (MINTs) and the corresponding supramolecular models.
Improvements of both Young's modulus and tensile strength of up to 200 % were
observed for the polystyrene-MINTs samples with an optimized loading of just
0.01 wt.%, while the supramolecular models with identical chemical composition
and loading showed negligible or even detrimental influence. This behavior is
found for three different types of SWNTs and two types of macrocycles.
Molecular dynamics simulations show that the polymer adopts an elongated
conformation parallel to the SWNT when interacting with MINT fillers,
irrespective of the macrocycle chemical nature, whereas a more globular
structure is taken upon facing with either pristine SWNTs or supramolecular
models. The MINT composite architecture thus leads to a more efficient
exploitation of the axial properties of the SWNTs and of the polymer chain at
the interface, in agreement with experimental results. Our findings demonstrate
that the mechanical bond imparts distinctive advantageous properties to SWNT
derivatives as polymer fillers.Comment: 39 pages, 19 figure
Cardiometabolic and Cardiovascular Complications of Obesity in Children
The rise in obesity in both children and adults has made obesity one of the biggest public health problems of this century. Obesity along with other factors such as hypertension, insulin resistance, dyslipidemia and diabetes mellitus
are risk factors for the development of cardiovascular diseases. Overweight and/or obesity during childhood and its maintenance until adult life has been associated with early stages of cardiovascular disease. For this reason, the aim of
this study is to revise the state of the art of cardiometabolic and cardiovascular complications related with overweight and/or obesity in children and adolescents. The first consequence of weight gain is an increase in adipose tissue, with
different distribution depending on the sex. The excess of fat mass entails dysfunction of adipose tissue with an altered secretion of adipokines and instauration of a proinflammatory environment, which may derive in metabolic syndrome condition. The increase of adipose tissue along with an increase in sympathetic nervous system, triggers an increased left ventricular mass and with a reduced diastolic function.
Therefore, obesity should be prevented from the early stages of life, in order to avoid obesity itself and the metabolic disturbances that could undermine quality of life further on
Espondilitis tuberculosa no es una metástasis vertebral: diagnóstico diferencial y tratamiento quirúrgico. A propósito de un caso
Presentamos el caso de una paciente con dorsalgia y clínica neurológica de varios meses de evolución
que ante las pruebas de imagen fue erróneamente diagnosticada de metástasis vertebral sin confirmación previa
con biopsia. El deterioro progresivo neurológico y las nuevas pruebas de imagen confirmaron el diagnóstico de tuberculosis
vertebral. La paciente fue tratada mediante curetaje, desbridamiento, fusión intersomática y osteosíntesis anterior
además del tratamiento médico. Hubo una recuperación neurológica de la función sensitiva, motora y esfinteriana
prácticamente completa al mes de la intervención. Tras 20 meses de evolución la paciente está asintomática sin
evidencia de progresión de la enfermedadWe report a patient with back pain and neurological symptoms several months of evolution to the test
image was wrongly diagnosed with spinal metastases without prior confirmation with biopsy. The progressive deterioration
of neurological and new imaging confirmed the diagnosis of spinal tuberculosis. The patient was treated by
curettage, debridement, anterior interbody fusion and internal fixation in addition to medical treatment. There neurological
recovery of sensory function, motor and sphincter almost complete month after the intervention. After 20
months of evolution, the patient is asymptomatic without evidence of disease progressio
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