pinecone/core-2020-05-10-deduplication huggingface dataset:
PMMA-sepiolite nanocomposites as new promising materials for the production of nanocellular polymers

In this work, a new system based on poly(methyl methacrylate) (PMMA) sepiolite nanocomposites
that allow producing nanocellular polymers by using the gas dissolution foaming technique
is described. Nanocomposites with different nanoparticle types and contents have been produced
by extrusion. From these blends, cellular materials have been fabricated using the so-called gas
dissolution foaming method. An extensive study of the effect of the processing parameters (saturation
pressure and foaming temperature) on the cellular materials produced has been performed.
Results showed that among the three sepiolites used, only those modified with a quaternary
ammonium salt are suitable for being used as nucleating agents in PMMA. With these
nanoparticles bimodal cellular polymers, with micro and nanometric cells, have been produced.
Cell sizes in the range of 300–500 nm and cell densities of the order of 1013–1014 nuclei/cm3
have been obtained in the nanocellular region. A foaming temperature of 80 °C and a wide range
of saturation pressures (between 10 and 30 MPa) and low particle contents (between 0.5 and
1.5 wt%) allow obtaining these materials. Furthermore, it has been found that cell size in the
nanometric population can be controlled by means of the particles content; a reduction in the cell size is obtained when the particles content increases. Finally, results indicate that an increase in the foaming temperature leads to cellular nanocomposites with lower relative densities (below 0.21) and larger cell sizes (above 450 nm).Financial support from FPU grant FPU14/02050 (V. Bernardo) from the Spanish Ministry of Education and Junta of Castile and Leon grant Q4718001C (J. Martín-de León) is gratefully acknowledged. Financial assistance from MINECO, FEDER, UE (MAT2015- 69234-R) and the Junta de Castile and Leon (VA011U16) are gratefully acknowledged. We would also like to thank the company Tolsa (Madrid, Spain) for supplying the sepiolites of this stud
Mixing effect on volume growth of Fagus sylvatica and Pinus sylvestris is modulated by stand density

Despite the increasing relevance of mixed stands due to their potential benefits; little information is available with regard to the effect of mixtures on yield in forest systems. Hence, it is necessary to study inter-specific relationships, and the resulting yield in mixed stands, which may vary with stand development, site or stand density, etc. In Spain, the province of Navarra is considered one of the biodiversity reservoirs; however, mixed forests occupy only a small area, probably as a consequence of management plans, in which there is an excessive focus on the productivity aspect, favoring the presence of pure stands of the most marketable species. The aim of this paper is to study how growth efficiencies of beech (Fagus sylvatica) and pine (Pinus sylvestris) are modified by the admixture of the other species and to determine whether stand density modifies interspecific relationships and to what extent.  Two models were fitted from Spanish National Forest Inventory data, for P. sylvestris and F. sylvatica respectively, which relate the growth efficiency of the species, i.e. the volume increment of the species divided by the species proportion by area, with dominant height, quadratic mean diameter, stocking degree, and the species proportions by area of each species. Growth efficiency of pine increased with the admixture of beech, decreasing this positive effect when stocking degree increased. However, the positive effect of pine admixture on beech growth was greater at higher stocking degrees. Growth efficiency of beech was also dependent on stand dominant height, resulting in a net negative mixing effect when stand dominant heights and stocking degrees were simultaneously low. There is a relatively large range of species proportions and stocking degrees which results in transgressive overyielding: higher volume increments in mixed stands than that of the most productive pure pine stands. We concluded that stocking degree is a key factor in between-species interactions, being the effects of mixing not always greater at higher stand densities, but it depends on species composition
Well-posed forms of the 3+1 conformally-decomposed Einstein equations

We show that well-posed, conformally-decomposed formulations of the 3+1
Einstein equations can be obtained by densitizing the lapse and by combining
the constraints with the evolution equations. We compute the characteristics
structure and verify the constraint propagation of these new well-posed
formulations. In these formulations, the trace of the extrinsic curvature and
the determinant of the 3-metric are singled out from the rest of the dynamical
variables, but are evolved as part of the well-posed evolution system. The only
free functions are the lapse density and the shift vector. We find that there
is a 3-parameter freedom in formulating these equations in a well-posed manner,
and that part of the parameter space found consists of formulations with causal
characteristics, namely, characteristics that lie only within the lightcone. In
particular there is a 1-parameter family of systems whose characteristics are
either normal to the slicing or lie along the lightcone of the evolving metric.Comment: 22 page
Gauge-boson propagator in out of equilibrium quantum-field system and
  the Boltzmann equation

We construct from first principles a perturbative framework for studying
nonequilibrium quantum-field systems that include gauge bosons. The system of
our concern is quasiuniform system near equilibrium or nonequilibrium
quasistationary system. We employ the closed-time-path formalism and use the
so-called gradient approximation. No further approximation is introduced. We
construct a gauge-boson propagator, with which a well-defined perturbative
framework is formulated. In the course of construction of the framework, we
obtain the generalized Boltzmann equation (GBE) that describes the evolution of
the number-density functions of gauge-bosonic quasiparticles. The framework
allows us to compute the reaction rate for any process taking place in the
system. Various processes, in turn, cause an evolution of the systems, which is
described by the GBE.Comment: 28 page
Massive Spin-2 Field in De Sitter Space

In this paper we present a covariant quantization of the ``massive'' spin-2
field on de Sitter (dS) space. By ``massive'' we mean a field which carries a
specific principal series representation of the dS group. The work is in the
direct continuation of previous ones concerning the scalar, the spinor and the
vector cases. The quantization procedure, independent of the choice of the
coordinate system, is based on the Wightman-Garding axiomatic and on
analyticity requirements for the two-point function in the complexified
pseudo-Riemanian manifold. Such a construction is necessary in view of
preparing and comparing with the dS conformal spin-2 massless case (dS linear
quantum gravity) which will be considered in a forthcoming paper and for which
specific quantization methods are needed
Simulation of the deformation of polycrystalline nanostructured Ti by computational homogenization

Computational homogenization by means of the finite element analysis of a representative volume element of the microstructure is used to simulate the deformation of nanostructured Ti. The behavior of each grain is taken into account using a single crystal elasto-viscoplastic model which includes the microscopic mechanisms of plastic deformation by slip along basal, prismatic and pyramidal systems. Two different representations of the polycrystal were used. Each grain was modeled with one cubic finite element in the first one while many cubic elements were used to represent each grain in the second one, leading to a model which includes the effect of grain shape and size in a limited number of grains due to the computational cost. Both representations were used to simulate the tensile deformation of nanostructured Ti processed by ECAP-C as well as the drawing process of nanostructured Ti billets. It was found that the first representation based in one finite element per grain led to a stiffer response in tension and was not able to predict the texture evolution during drawing because the strain gradient within each grain could not be captured. On the contrary, the second representation of the polycrystal microstructure with many finite elements per grain was able to predict accurately the deformation of nanostructured Ti
Interval-based ranking in noisy evolutionary multiobjective optimization

As one of the most competitive approaches to multi-objective optimization, evolutionary algorithms have been shown to obtain very good results for many realworld multi-objective problems. One of the issues that can affect the performance of these algorithms is the uncertainty in the quality of the solutions which is usually represented with the noise in the objective values. Therefore, handling noisy objectives in evolutionary multi-objective optimization algorithms becomes very important and is gaining more attention in recent years. In this paper we present ?-degree Pareto dominance relation for ordering the solutions in multi-objective optimization when the values of the objective functions are given as intervals. Based on this dominance relation, we propose an adaptation of the non-dominated sorting algorithm for ranking the solutions. This ranking method is then used in a standardmulti-objective evolutionary algorithm and a recently proposed novel multi-objective estimation of distribution algorithm based on joint variable-objective probabilistic modeling, and applied to a set of multi-objective problems with different levels of independent noise. The experimental results show that the use of the proposed method for solution ranking allows to approximate Pareto sets which are considerably better than those obtained when using the dominance probability-based ranking method, which is one of the main methods for noise handling in multi-objective optimization
Lepton-specific two Higgs doublet model as a solution of muon g − 2 anomaly

We discuss the Type-X (lepton-specific) two Higgs doublet model as a solution of the anomaly of the muon g − 2. We consider various experimental constraints on the parameter space such as direct searches for extra Higgs bosons at the LEP II and the LHC Run-I, electroweak precision observables, the decay of B s → μ + μ − , and the leptonic decay of the tau lepton. We find that the measurement of the tau decay provides the most important constraint, which excludes the parameter region that can explain the muon g − 2 anomaly at the 1σ level. We then discuss the phenomenology of extra Higgs bosons and the standard model-like Higgs boson ( h ) to probe the scenario favored by the g − 2 data at the collider experiments. We find that the 4 τ , 3 τ and 4 τ + W/Z signatures are expected as the main signal of the extra Higgs bosons at the LHC. In addition, we clarify that the value of the hττ coupling is predicted to be the standard model value times about −1 . 6 to −1 . 0, and the branching fraction of the h → γγ mode deviates from the standard model prediction by −30% to −15%. Furthermore, we find that the exotic decay mode, h decaying into the Z boson and a light CP-odd scalar boson, is allowed, and its branching fraction can be a few percent. These deviations in the property of h will be tested by the precision measurements at future collider experiments
Three-point correlators from string amplitudes: mixing and Regge spins

This paper has two parts. We first compute the leading contribution to the strong-coupling mixing between the Konishi operator and a double-trace operator composed of chiral primaries by using flat-space vertex operators for the string-duals of the operators. We then compute the three-point functions for protected or unprotected scalar operators with higher spin operators on the leading Regge trajectory. Here we see that the nontrivial spatial structures required by conformal invariance arise naturally from the form of the polarization tensors in the vertex operators. We find agreement with recent results extracted from Mellin amplitudes for four-point functions, as well as with earlier super-gravity calculations. We also obtain some new results for other combinations of operators
Testing solar neutrino MSW oscillations at low delta m^2 through time
  variations of event rates in GNO and BOREXINO

The Mikheyev-Smirnov-Wolfenstein (MSW) explanation of the solar neutrino
problem is currently compatible with three distinct regions of the two-neutrino
oscillation parameter space (delta m^2,sin^2 2theta). We focus on the region
with the lowest value of delta m^2 (~10^{-7} eV^2), which implies significant
Earth regeneration effects for low-energy solar neutrinos. We point out that
such effects are not only observable as day-night variations of neutrino event
rates in the real-time BOREXINO experiment, but also as seasonal variations in
the radiochemical Gallium Neutrino Observatory (GNO) at Gran Sasso. We present
detailed calculations of the difference between winter and summer rates in GNO
(six months averages) in excess of the trivial seasonal variation due to the
Earth orbital eccentricity. We show that, within the low-delta m^2 MSW
solution, the net winter-summer GNO rate difference amounts to 4-6 SNU, with a
dominant contribution from pp neutrinos. We also give analytical expressions
for the winter and summer solar exposure functions at the Gran Sasso site
Transmission properties of double-gap asymmetric split ring resonators in terahertz region

We investigated the electromagnetic properties of the metamaterials that consist of double-gap split ring resonators (SRRs) in the terahertz region. We found that varying the position of one gap with respect to the other causes the resonant frequency of the SRRs to shift over a broad range. This frequency shift is attributed to the change in the combined capacitance that consists of two capacitances of gaps connected in series and an additional capacitance connected in parallel to the others. Our findings are also verified by obtaining good agreement between experiments and simulations
Petri nets for modelling metabolic pathways: a survey

In the last 15 years, several research efforts have been directed towards the representation and the analysis of metabolic pathways by using Petri nets. The goal of this paper is twofold. First, we discuss how the knowledge about metabolic pathways can be represented with Petri nets. We point out the main problems that arise in the construction of a Petri net model of a metabolic pathway and we outline some solutions proposed in the literature. Second, we present a comprehensive review of recent research on this topic, in order to assess the maturity of the field and the availability of a methodology for modelling a metabolic pathway by a corresponding Petri net
A simple digital-optical system to improve accuracy of hot-wire measurements

A high precision traverse mechanism with micro-resolution was designed to capture accurately the velocity profile of the very thin turbulent attachment line on a swept body. To ensure that the traverse mechanism could position the hot wire reliably, a simple digital optical system was designed to check the performance of the traverse by measuring the displacement of the hot wire: a vertical displacement of 2.4µm was achievable and this could be further reduced to 0.6µm using micro-stepping. Due to the simplicity of the set-up it was equally useful for probe wall positioning and the velocity profiles captured clearly demonstrated that the optical set-up helped in resolving the near wall flow more accurately, regardless of the thinness of the boundary layer. The captured data compare well with the results from similar investigations, with arguably higher precision achieved
Factors associated with poor outcomes among adults hospitalised for influenza in France: A three-year prospective multicenter study

International audienceBackground: Influenza is an important cause of serious illness and death, particularly in elderly and high-risk groups. Objectives Aim of this study was to identify factors associated with poor outcomes among adults hospitalized in France for laboratory-confirmed seasonal influenza. Study design Patients hospitalized for influenza were identified in a prospective, multicenter study carried out in French hospitals during three consecutive influenza seasons (2012–2015). Influenza virus infection was confirmed by reverse transcription polymerase chain reaction. Sociodemographic and clinical variables were compared according to the virus type and subtype. Risk factors for complications, intensive care unit (ICU) admission and death were analyzed by backward stepwise logistic regression. Results The study population consisted of 566 patients, of whom 56% were older than 65 years and 82% had underlying chronic illnesses. Type A influenza viruses infected 422 patients (75%), including subtype H3N2 in 239 patients (57%). The prior vaccine coverage rate was 38%. Complications occurred in 255 patients (45%), consisting mainly of pneumonia (n = 143, 30%) and respiratory failure (n = 116, 20%). Eighty-three patients (15%) were admitted to an ICU, and the in-hospital mortality rate was 4% (n = 21). Sixty-six patients (12%) received oseltamivir. Age over 65 years was the only identified risk factor for complications. Risk factors for ICU admission were an absence of vaccination, no oseltamivir administration before admission, pre-existing chronic respiratory disease, and current smoking. Age over 65 years and ICU admission were risk factors for death. Conclusions Older individuals and patients with underlying conditions are most at risk of influenza complications. Vaccination and early oseltamivir administration, both of which are recommended for these patients, appear to reduce ICU admission
Tree Pattern Rewriting Systems

International audienceClassical verification often uses abstraction when dealing with data. On the other hand, dynamic XML-based applications have become pervasive, for instance with the ever growing importance of web services. We define here Tree Pattern Rewriting Systems (TPRS) as an abstract model of dynamic XML-based documents. TPRS systems generate infinite transition systems, where states are unranked and unordered trees (hence possibly modeling XML documents). The guarded transition rules are described by means of tree patterns. Our main result is that given a TPRS system (T, R), a tree pattern P and some integer k such that any reachable document from T has depth at most k, it is decidable (albeit of non elementary complexity) whether some tree satisfying P is reachable from T
Fluid circulation in the depths of accretionary prisms: an example of the Shimanto Belt, Kyushu, Japan

International audienceAccretionary prisms constitute ideal targets to study fluid circulation and fluid-rock interactions at depths beyond the reach of active margin deep drilling. The highest-grade rocks from the Shimanto Belt on Kyushu were buried under 3-5 kbars at ~ 300°C (Toriumi and Teruya, 1988). They contain abundant quartz veins, formed throughout burial and exhumation and variably affected by brittle and ductile deformation.Cathodoluminescence (CL) reveals the existence of two distinct types of quartz, characterized by a blue and brown color, respectively. CL-blue quartz fills macro-veins (width ≥ 10μm), while CL-brown quartz is present in micro-veins (width ~ 1 − 10μm) and ductilely recrystallized domains. On the basis of microstructures, the fluids associated with the CL-blue and CL-brown quartz are interpreted as “external” and “local”, respectively. Quartz growth rims of alternating CL colors as well as mutually cross-cutting veins show that the two fluids cyclically wetted the host rock.From fluid inclusions analysis, the fluid associated with CL-blue quartz has a salinity similar to seawater, while the fluid associated with CL-brown quartz is less saline. In addition, CL-blue quartz is richer in aluminum than the CL-brown one. In contrast to the salinity/aluminum signature, the δ18O isotopic signature of both quartz types is similar and buffered by host rock. The difference between the preservation of the salinity signature of the fluid and the loss of its δ18O signature is explained by quicker exchange kinetics and larger host rock buffering capacity for isotopic reequilibration.The “local” fluid, associated with CL-brown quartz, reflects the dilution of pore water by the pure water produced by prograde dehydration reactions of clay minerals. The “external” fluid associated with CL-blue quartz is interpreted as seawater or pore water from shallow (depth<1-2 km below seafloor) sediments. We propose that downward percolation of shallow water to depths ~ 10km is a transient process associated with mega-earthquakes
Influence of the regional topography on the remote emplacement of hydrothermal systems with examples of Ticsani and Ubinas volcanoes, Southern Peru.

International audiencePresent work studies the influence of the regional topography on the hydrothermal fluid flow pattern in the subsurface of a volcanic complex. We discuss how the advective transfer of heat from a magmatic source is controlled by the regional topography for different values of the averaged permeability. For this purpose, we use a 2-D numerical model of coupled mass and heat transport and new data sets acquired at Ticsani and Ubinas, two andesitic volcanoes in Southern Peru which have typical topography, justifying this approach. A remarkable feature of these hydrothermal systems is their remote position not centered on the top of the edifice. It is evidenced by numerous hot springs located in more than 10 km distance from the top of each edifice. Upwelling of thermal water is also inferred from a positive self-potential anomaly at the summit of the both volcanoes, and by ground temperatures up to 37°C observed at Ticsani. Our model results suggest that the regional topographic gradient is able to significantly divert the thermal water flow and can lead to an asymmetric emplacement of the hydrothermal system even considering a homogeneous permeability of the edifice. Inside the thermal flow, the hydraulic conductivity increases with the decrease of temperature-related viscosity, focusing the flow towards the surface and creating a hydrothermal zone at a large lateral distance from the heat source. The location and temperature of the hot springs together with the water table position given by self-potential data can be used to constrain the average permeability of the edifice, a key parameter influencing fluid flow and associated advective heat transfer in the direction opposite to the regional topographic gradient. Our study allows to explain the emplacement of the hydrothermal systems at volcanoes with asymmetric edifices or even the absence of a shallow hydrothermal system. These results can be generalized to the study of non-volcanic hydrothermal systems