pinecone/core-2020-05-10-deduplication huggingface dataset:
Anomalous temperature-induced volume contraction in GeTe

The recent surge of interest in phase change materials GeTe,
Ge$_2$Sb$_2$Te$_5$, and related compounds motivated us to revisit the
structural phase transition in GeTe in more details than was done before.
Rhombohedral-to-cubic ferroelectric phase transition in GeTe has been studied
by high resolution neutron powder diffraction on a spallation neutron source.
We determined the temperature dependence of the structural parameters in a wide
temperature range extending from 309 to 973 K. Results of our studies clearly
show an anomalous volume contraction of 0.6\% at the phase transition from the
rhombohedral to cubic phase. In order to better understand the phase transition
and the associated anomalous volume decrease in GeTe we have performed phonon
calculations based on the density functional theory. Results of the present
investigations are also discussed with respect to the experimental data
obtained for single crystals of GeTe
Atomic diffusion in laser surface modified AISI H13 steel

This paper presents a laser surface modification process of AISI H13 steel using 0.09 and 0.4 mm of laser spot sizes with an aim to increase surface hardness and investigate elements diffusion in laser modified surface. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, pulse repetition frequency (PRF), and overlap percentage. The hardness properties were tested at 981 mN force. Metallographic study and energy dispersive X-ray spectroscopy (EDXS) were performed to observe presence of elements and their distribution in the sample surface. Maximum hardness achieved in the modified surface was 1017 HV0.1. Change of elements composition in the modified layer region was detected in the laser modified samples. Diffusion possibly occurred for C, Cr, Cu, Ni, and S elements. The potential found for increase in surface hardness represents an important method to sustain tooling life. The EDXS findings signify understanding of processing parameters effect on the modified surface composition
Local burning velocity in a Bunsen jet flame

A PIV-based system has been set-up for the simultaneous measurement of the local burning velocity of premixed flames and the flame stretch due to the flame front curvature and the incoming flow strain rate. For moderately short jet flames, these measurements allow an indirect determination of the Markstein length, according to Clavin and Joulin (C–J) theory. For tall flames, the flame curvature becomes relatively large in a region around the tip where the C–J theory breaks down. However, our experiments confirm the appearance of a new linear relation between burning velocity and curvature at the flame tip. This relation defines a new proportionality factor which is probably associated to the evolution from rounded tips to slender tips when the jet velocity is increased
Parametric ordering of complex systems

Cellular automata (CA) dynamics are ordered in terms of two global parameters, computable a priori from the description of rules. While one of them (activity) has been used before, the second one is new; it estimates the average sensitivity of rules to small configurational changes. For two-well-known families of rules, the Wolfram complexity classes cluster satisfactorily. The observed simultaneous occurrence of sharp and smooth transitions from ordered to disordered dynamics in CA can be explained with the two-parameter diagram
Hunting composite vector resonances at the LHC: naturalness facing data

We introduce a simplified low-energy effective Lagrangian description of the phenomenology of heavy vector resonances in the minimal composite Higgs model, based on the coset SO(5)/SO(4), analysing in detail their interaction with lighter top partners. Our construction is based on robust assumptions on the symmetry structure of the theory and on plausible natural assumptions on its dynamics. We apply our simplified approach to triplets in the representations ( 3 , 1 ) and ( 1 , 3 ) and to singlets in the representation ( 1 , 1 ) of SO(4). Our model captures the basic features of their phenomenology in terms of a minimal set of free parameters and can be efficiently used as a benchmark in the search for heavy spin-1 states at the LHC and at future colliders. We devise an efficient semi-analytic method to convert experimental limits on σ × BR into bounds on the free parameters of the theory and we recast the presently available 8 TeV LHC data on experimental searches of spin-1 resonances as exclusion regions in the parameter space of the models. These latter are conveniently interpreted as a test of the notion of naturalness
Searching for sterile neutrinos at the ESS ν SB

The ESS ν SB project is a proposed neutrino oscillation experiment based on the European Spallation Source with the search for leptonic CP violation as its main aim. In this letter we show that a near detector at around 1 km distance from the beamline is not only very desirable for keeping the systematic errors affecting the CP search under control, but would also provide a significant sensitivity probe for sterile neutrino oscillations in the region of the parameter space favored by the long-standing LSND anomaly. We find that the effective mixing angle θ μe can be probed down to sin 2 (2 θ μe ) ≃ 2(8) · 10 −3 at 5 σ assuming 15% bin-to-bin (un)correlated systematics
On partially massless theory in 3 dimensions

We analyze the first-order formulation of the ghost-free bigravity model in three-dimensions known as zwei-dreibein gravity. For a special choice of parameters, it was argued to have an additional gauge symmetry and give rise to a partially massless theory. We provide a thorough canonical analysis and identify that whether the theory becomes partially massless depends on the form of the stability condition of the secondary constraint responsible for the absence of the ghost. Generically, it is found to be an equation for a Lagrange multiplier implying that partially massless zwei-dreibein gravity does not exist.  However, for special backgrounds this condition is identically satisfied leading to the presence of additional symmetries, which however disappear at quadratic order in perturbations
The impedance and conductivity studies on BiFeO3 and 0.90BiFeO3-0.10Bi0.5Na0.5TiO3 ceramics

Polycrystalline BiFeO\ud
3\ud
 and 0.90BiFeO\ud
3\ud
-0.10Bi\ud
0.5\ud
Na\ud
0.5\ud
TiO\ud
3\ud
 compounds were synthesized by conventional \ud
solid state route. The compounds were crystallized in rhombohedral structure with \ud
R3c\ud
 space group. Complex \ud
impedance studies revealed that insulating character of both grain and grain boundaries were improved in 0.90BiFeO\ud
3\ud
-\ud
0.10Bi\ud
0.5\ud
Na\ud
0.5\ud
TiO\ud
3\ud
 compound. Both complex and modulus plots confirmed the presence of non- Debye type relaxations \ud
in these compounds. Frequency dependence of AC conductivity at different temperatures suggests that charge carriers \ud
follow correlated barrier hopping (CBH) model. Estimated activation energies indicated that oxygen vacancies \ud
movements are the prime contributors to the conduction in the measured temperature rang
Effects of thermal fluctuations on thermal inflation

The mechanism of thermal inflation, a relatively short period of accelerated expansion after primordial inflation, is a desirable ingredient for a certain class of particle physics models if they are not to be in contention with the cosmology of the early Universe. Though thermal inflation is most simply described in terms of a thermal effective potential, a thermal environment also gives rise to thermal fluctuations that must be taken into account. We numerically study the effects of these thermal fluctuations using lattice simulations. We conclude that though they do not ruin the thermal inflation scenario, the phase transition at the end of thermal inflation proceeds through phase mixing and is therefore not accompanied by the formations of bubbles nor appreciable amplitude of gravitational waves
TCMS inhibits ATP synthesis in mitochondria: a systematic analysis of the inhibitory mechanism

The interactions of the antifouling compound TCMS (2,3,5,6-tetrachloro-4-methylsulphonyl pyridine) with rat liver mitochondria have been investigated. The results indicate that the compound inhibits ATP synthesis. Further investigations regarding the ATP syn- thesis mechanism suggest that TCMS inhibits succinic dehydrogenase of the mitochondrial respiratory chain. As the respiratory chain is similar in all living organisms, it can be concluded that the toxic effect of TCMS most likely depend on the different bioavailability of the compound and on the different importance of mitochondria in the ATP production in the animal species
On the relations between Markov chain lumpability and reversibility

In the literature, the notions of lumpability and time reversibility for large Markov chains have been widely used to efficiently study the functional and non-functional properties of computer systems. In this paper we explore the relations among different definitions of lumpability (strong, exact and strict) and the notion of time-reversed Markov chain. Specifically, we prove that an exact lumping induces a strong lumping on the reversed Markov chain and a strict lumping holds both for the forward and the reversed processes. Based on these results we introduce the class of λρ-reversible Markov chains which combines the notions of lumping and time reversibility modulo state renaming. We show that the class of autoreversible processes, previously introduced in Marin and Rossi (Proceedings of the IEEE 21st international symposium on modeling, analysis and simulation of computer and telecommunication systems MASCOTS, pp. 151–160, 2013), is strictly contained in the class of λρ-reversible chains
Using strategic performance measurement systems for strategy formulation: Does it work in dynamic environments?

This paper examines how strategic performance measurement systems (SPMS) influence organisational performance through the shaping of the strategic agendas and strategic decision arrays that result from the processes of (re)formulation of intended strategies. Using a combination of archival and survey data collected from 267 medium and large Spanish companies, we find evidence supporting a positive association between SPMS and organisational performance which is mediated by the comprehensiveness of the strategic decision arrays. We find this mediation is negatively moderated by the level of environmental dynamism, so that the comprehensiveness of strategic decision arrays that result from strategy (re)formulation processes mediates the association between SPMS and organisational performance when environmental dynamism is low, but not when environmental dynamism is high
A Classical Realizability Model for a Semantical Value Restriction

We present a new type system with support for proofs of programs in a
call-by-value language with control operators. The proof mechanism relies on
observational equivalence of (untyped) programs. It appears in two type
constructors, which are used for specifying program properties and for encoding
dependent products. The main challenge arises from the lack of expressiveness
of dependent products due to the value restriction. To circumvent this
limitation we relax the syntactic restriction and only require equivalence to a
value. The consistency of the system is obtained semantically by constructing a
classical realizability model in three layers (values, stacks and terms)
Relationship between wave reflection and renal damage in hypertensive patients

OBJECTIVE: Arterial stiffening has harmful effects; peripheral pulse wave reflections deleteriously increase central pressure, but on the contrary they could also possibly be protective, as the pulse is transmitted to the microcirculation to a lesser extent. The aim of this study was, therefore, to explore the relationship between wave reflection and small vessel damage in the kidney.\ud
\ud
METHODS: In 216 hypertensive patients, data on renal resistive index, obtained by Doppler ultrasound sampling of the interlobar arteries, as well as augmentation index (AIx) and carotid-to-femoral pulse wave velocity (PWV), were retrospectively analyzed. Reflection magnitude was computed through a triangular flow estimate.\ud
\ud
RESULTS: AIx and reflection magnitude were positively correlated with resistive index; age, BMI, central pulse pressure, and cholesterol, but not AIx or reflection magnitude, were predictors of resistive index in multivariate analyses. Crossing tertiles of PWV and AIx, resistive index did not differ between patients with high AIx and low PWV (n=25; 0.632 (0.064)) and those with low AIx and high PWV (n=17; 0.645 (0.053)), despite a difference in reflection magnitude (74.9 (6.7) vs. 51.2 (7.3)%; P<0.001).\ud
\ud
CONCLUSION: Pressure wave reflection is positively correlated with resistive index in a hypertensive population. No negative relationship was found even adjusting for confounders or when it was examined separately from the influence of arterial stiffness. These findings do not support the hypothesis of peripheral wave reflections having a significant protective role for the microcirculation of a low resistance vascular bed such as the kidney
Comparing the Luttinger–Kohn–Pikus–Bir and the Empiric K·P Hamiltonians in quantum dot intermediate band solar cells manufactured in zincblende semiconductors

The calculation of the energy spectrum and absorption coefficients of quantum dot nanostructured intermediate band solar cells using the Empiric K·P Hamiltonian method and its agreement with experimental data are summarized. The well established Luttinger Kohn Hamiltonian modified by Pikus and Bir for strained material, such as quantum dot arrays, is presented using a simplified strain field that allows for square band offsets. The energy spectrum and absorption coefficients are calculated with this new Hamiltonian. With the approximations made the energy spectrum results to be exactly the same but the absorption coefficient fits experiments less accurately. The computer time using the latter Hamiltonian is much longer than the former one
Efficient Photonic Crystal Cavity-Waveguide Couplers

Coupling of photonic crystal (PC) linear three-hole defect cavities (L3) to PC waveguides is theoretically and experimentally investigated. The systems are designed to increase the overlap between the evanescent cavity field and the waveguide mode, and to operate in the linear dispersion region of the waveguide. Our simulations indicate increased coupling when the cavity is tilted by 60 degrees with respect to the waveguide axis, which we have also confirmed by experiments. We obtained up to 90% coupling efficiency into the waveguide
Spin and Clifford algebras, an introduction

40 pages ; published version with slight modifications for on-line reading (Ed. UNAM-FQ 2002, México)International audienceIn this short pedagogical presentation, we introduce the spin groups and the spinors from the point of view of group theory. We also present, independently, the construction of the low dimensional Clifford algebras. And we establish the link between the two approaches. Finally, we give some notions of the generalisations to arbitrary spacetimes, by the introduction of the spin and spinor bundles
Algebraic Bethe ansatz approach to the asymptotic behavior of correlation functions

78 pagesInternational audienceWe describe a method to derive, from first principles, the long-distance asymptotic behavior of correlation functions of integrable models in the framework of the algebraic Bethe ansatz. We apply this approach to the longitudinal spin- spin correlation function of the XXZ Heisenberg spin-1/2 chain (with magnetic field) in the disordered regime as well as to the density-density correlation func- tion of the interacting one-dimensional Bose gas. At leading order, the results confirm the Luttinger liquid and conformal field theory predictions
Gradient discretization of hybrid dimensional Darcy flows in fractured porous media

International audienceThis article deals with the discretization of hybrid dimensional model of Darcy flow in fractured porous media. These models couple the flow in the fractures represented as the surfaces of codimension one with the flow in the surrounding matrix. The convergence analysis is carried out in the framework of Gradient schemes which accounts for a large family of conforming and nonconforming discretizations. The Vertex Approximate Gradient (VAG) scheme and the Hybrid Finite Volume (HFV) scheme are applied to such models and are shown to verify the Gradient scheme framework. Our theoretical results are confirmed by a few numerical experiments performed both on tetrahedral and hexahedral meshes in heterogeneous isotropic and anisotropic media
The correspondence between Élisée Reclus and Pëtr Kropotkin as a source for the history of geography

International audienceThe State Archive of the Russian Federation (GARF) contains a corpus of around one hundred letters sent by Élisée Reclus to Pëtr Kropotkin between 1882 and 1905. The correspondence is mainly concerned with their geographical works, notably the collaboration of Kropotkin with the Nouvelle Géographie Universelle (1876e1894) and the Brussels edition of Kropotkin's Orographie de la Sibérie (1904), edited by Reclus. In this paper, we deal first with the importance of this source: it is an example of the material work of a network of geographers who were at the same time the founders of the international anarchist movement. We suggest the correspondence falls into two parts: the first period (1882e1886) when Reclus was in exile in Switzerland after the Paris Commune of 1871, and Kropotkin was in prison in France; and the second period (1888e1905) when the two anarchist geographers discuss the role of geographical education, historical geography in Europe and its part in the globalisation of their era. The archive also contains significant evidence of their relationships with British geography: Kropotkin lived in London and joined the Royal Geographical Society and was on familiar terms with leading Fellows, such as John Scott Keltie and Halford Mackinder. The paper addresses the significance of the correspondence for understanding the relationships between geography, politics and public education, and the role of these heterodox geographers in the construction of geographical knowledge. The paper is accompanied by the publication, for the first time, of an edited selection of the letters
Azimuthal Anisotropy at Valhall: the Helmholtz Equation Approach

International audienceWe used 6 hours of continuous vertical records from 2320 sensors of the Valhall Life of Fields Seismic network to compute 2 690 040 cross-correlation functions between the full set of sensor pair combinations. We applied the 'Helmholtz tomography' approach combined with the ambient noise correlation method to track the wave front across the network with every station considered as a virtual source. The gradient of the interpolated phase travel time gives us an estimate of the local phase speed and of the direction of wave propagation. By combining the individual measurements for every station, we estimated the distribution of Scholte's wave phase speeds with respect to azimuth. The observed cosine pattern indicates the presence of azimuthal anisotropy. The elliptic shape of the fast anisotropy direction is consistent with results of previous shear wave splitting studies and reflects the strong seafloor subsidence due to the hydrocarbon reservoir depletion at depth and is in good agreement with geomechanical modeling
Review of Self-potential methods in Hydrogeophysics

International audienceThe self-potential (SP) method is a passive geophysical method based on the natural occurrence of electrical fields on the Earth's surface. Combined with other geophysical methods, SP surveys are especially useful for localizing and quantifying groundwater flows and pollutant plume spreading, and estimating pertinent hydraulic properties of aquifers (water table, hydraulic conductivity). Laboratory experiments have shown that the involved coupling coefficients mainly depend on the fluid chemistry, conductivity and pH, and on the soil or rock properties. The interpretation of SP observations can be done qualitatively, for instance by correlation of SP gradients with water fluxes (through electrokinetics) or salt fluxes (through electro-diffusion). In recent years, the interpretation has been improved with the help of modelling or/and inversion of the Poisson equation and endeavours to estimate hydraulic parameters by means of the intensity of electric current sources caused by underground flows
NOSTOS - Spherical TPCs

XIII International Symposium on Very High Energy Cosmic Ray Interactions at the NESTOR Institute - Pylos, Grece, 6-12 Septembre 2004A new concept, the spherical TPC, presents unique advantages when low energy neutrinos are to be detected. Some of the applications are: a) observation of the e oscillation when emitted by a tritium source ( = 14 keV) in a 10 m radius sphere. This project, baptized NOSTOS, intends to give the mixing angle 13, the Weinberg angle and a much lower limit (< 10-12 ?B ) of the neutrino magnetic moment, b) an array of small (radius 2-4 m), cheap spheres scattered around the world would be perfect to monitor extragalactic supernovae, c) detect the spectrum of low energy (pp - 7Be) solar neutrinos
Adsorption of imidazolium and pyridinium ionic liquids onto montmorillonite: characterization and thermodynamic calculations

International audienceFive first generation ionic liquids (RTILs : BMImCl, OMImCl, AMImCl, BPyBr and OPyBr) were intercalated into the layered structure of a Na-montmorillonite by dispersion in aqueous solutions ([RTIL] ⩽ 20 mmol.L-1). For all ionic liquids, the intercalation expanded the spacing of the silicate layers, as measured by X-ray diffraction. FTIR, thermogravimetric analyses and sodium titrations of the solutions after intercalation proved the adsorption of the RTILs through a cation exchange mechanism. Adsorption isotherms, done at pH = 7 and at 25°C, displayed that the maximum adsorption capacity of the substrates was closely linked to the nature of the organic cation and the length of the alkyl chain (BPyBr > OPyBr ∼ AMImCl ∼ BMImCl > OMImCl). For the five RTILs, calculated parameters obtained from the adsorption isotherms studied at 3 temperatures (25°C, 40°C and 55°C) concluded to an endothermic and spontaneous adsorption reaction
Oil market modelling: A comparative analysis of fundamental and latent factor approaches

International audienceWe formally compare fundamental factor and latent factor approaches to oil price modelling. Fundamental modelling has a long history in seeking to understand oil price movements, while latent factor modelling has a more recent and limited history, but has gained popularity in other financial markets. The two approaches, though competing, have not formally been compared as to effectiveness. For a range of short-medium-and long-dated WTI oil futures we test a recently proposed five-factor fundamental model and a Principal Component Analysis latent factor model. Our findings demonstrate that there is no discernible difference between the two techniques in a dynamic setting. We conclude that this infers some advantages in adopting the latent factor approach due to the difficulty in determining a well specified fundamental model