pinecone/core-2020-05-10-deduplication huggingface dataset:
Linear Sparse Differential Resultant Formulas

Let P be a system of n linear nonhomogeneous ordinary differential polynomials in a set U of n-1 differential indeterminates.\ud
Differential resultant formulas are presented to eliminate the differential indeterminates in U from P. These formulas are determinants of coefficient matrices of appropriate sets of derivatives of the differential polynomials in P, or in a linear perturbation Pe of P.\ud
In particular, the formula dfres(P) is the determinant of a matrix M(P) having no zero columns if the system P is ``super essential".\ud
As an application, if the system PP is sparse generic, such formulas can be used to compute the differential resultant dres(PP) introduced by Li, Gao and Yuan
The extended Betz–Lanchester limit

A proposal for an extended formulation of the power coefficient of a wind turbine is presented. This new formulation is a generalization of the Betz–Lanchester expression for the power coefficient as function of the axial deceleration of the wind speed provoked by the wind turbine in operation. The extended power coefficient takes into account the benefits of the power produced and the cost associated to the production of this energy. By the simple model proposed is evidenced that the purely energetic optimum operation condition giving rise to the Betz–Lanchester limit (maximum energy produced) does not coincide with the global optimum operational condition (maximum benefit generated) if cost of energy and degradation of the wind turbine during operation is considered. The new extended power coefficient is a general parameter useful to define global optimum operation conditions for wind turbines, considering not only the energy production but also the maintenance cost and the economic cost associated to the life reduction of the machine
Higgs and Z boson associated production via gluon fusion in the SM and the 2HDM

We analyse the associated production of Higgs and Z boson via heavy-quark loops at the LHC in the Standard Model and beyond. We first review the main features of the Born 2 → 2 production, and in particular discuss the high-energy behaviour, angular distributions and Z boson polarisation. We then consider the effects of extra QCD radiation as described by the 2 → 3 loop matrix elements, and find that they dominate at high Higgs transverse momentum. We show how merged samples of 0- and 1-jet multiplicities, matched to a parton shower can provide a reliable description of differential distributions in ZH production. In addition to the Standard Model study, results in a generic two-Higgs-doublet-model are obtained and presented for a set of representative and experimentally viable benchmarks for Zh0, ZH0 and ZA0 production. We observe that various interesting features appear either due to the resonant enhancement of the cross-section or to interference patterns between resonant and non-resonant contribution
Thermoelectric conductivities at finite magnetic field and the Nernst effect

We study the thermoelectric conductivities of a strongly correlated system in the presence of a magnetic field by the gauge/gravity duality. We consider a class of Einstein-Maxwell-Dilaton theories with axion fields imposing momentum relaxation. General analytic formulas for the direct current (DC) conductivities and the Nernst signal are derived in terms of the black hole horizon data. For an explicit model study, we analyse in detail the dyonic black hole modified by momentum relaxation. In this model, for small momentum relaxation, the Nernst signal shows a bell-shaped dependence on the magnetic field, which is a feature of the normal phase of cuprates. We compute all alternating current (AC) electric, thermoelectric, and thermal conductivities by numerical analysis and confirm that their zero frequency limits precisely reproduce our analytic DC formulas, which is a non-trivial consistency check of our methods. We discuss the momentum relaxation effects on the conductivities including cyclotron resonance poles
QED trace anomaly, non-local Lagrangians and quantum equivalence principle violations

We discuss the derivation of the trace anomaly using a non-local effective action at one loop. This provides a simple and instructive form and emphasizes infrared physics. We then use this example to explore several of the properties of non-local actions, including displaying the action for the full non-local energy-momentum tensor. As an application, we show that the long-distance corrections at one loop lead to quantum violations of some classical consequences of the equivalence principle, for example producing a frequency dependence of the gravitational bending of light
Natural inflation and moduli stabilization in heterotic orbifolds

We study moduli stabilization in combination with inflation in heterotic orbifold compactifications in the light of a large Hubble scale and the favored tensor-to-scalar ratio r ≈ 0 . 05. To account for a trans-Planckian field range we implement aligned natural inflation. Although there is only one universal axion in heterotic constructions, further axions from the geometric moduli can be used for alignment and inflation. We argue that such an alignment is rather generic on orbifolds, since all non-perturbative terms are determined by modular weights of the involved fields and the Dedekind η function. We present two setups inspired by the mini-landscape models of the ℤ 6 − II orbifold which realize aligned inflation and stabilization of the relevant moduli. One has a supersymmetric vacuum after inflation, while the other includes a gaugino condensate which breaks supersymmetry at a high scale
Inflation and dark energy with a single superfield

We discuss the possibility to construct supergravity models with a single superfield describing inflation as well as the tiny cosmological constant V ∼ 10−120. One could expect that the simplest way to do it is to study models with a supersymmetric Minkowski vacuum and then slightly uplift them. However, due to the recently proven no-go theorem, such a tiny uplifting cannot be achieved by a small modification of the parameters of the theory. We illustrate this general result by investigation of models with a single chiral superfield recently proposed by Ketov and Terada. We show that the addition of a small constant or a linear term to the superpotential of a model with a stable supersymmetric Minkowski vacuum converts it to an AdS vacuum, which results in a rapid cosmological collapse. One can avoid this problem and uplift a supersymmetric Minkowski vacuum to a dS vacuum with V0∼ 10−120 without violating the no-go theorem by making these extra terms large enough. However, we show that this leads to a strong supersymmetry breaking in the uplifted vacua
SU(5) orbifold GUT in noncommutative geometry

In this paper, we apply the orbifold GUT mechanism to the SU(5) model in noncommutative geometry, including the fermionic sector. Imposing proper parity assignments for “constituent fields” of bosons and fermions, the couplings between fermions and the heavy bosons , , and are prohibited by the parity symmetry. As a result, the derived fermionic Lagrangian is just that of the standard model, and proton decay is forbidden at tree level. If quantum fluctuation respects the parity symmetry, the process will be naturally suppressed or even forbidden completely
The eejj excess signal at the LHC and constraints on leptogenesis

We review the  non-supersymmetric (Extended) Left-Right Symmetric Models (LRSM) and low energy E6-based models to investigate if they can explain both the recently detected excess eejj signal at CMS and leptogenesis. The eejj excess can be explained from the decay of the right-handed gauge bosons (WR) with mass ∼ TeV in certain variants of the LRSM (with gL≠ gR). However such scenarios can not accommodate high-scale leptogenesis. Other attempts have been made to explain leptogenesis while  keeping the WR mass almost within the reach of the LHC by considering the resonant leptogenesis scenario in the context of the LRSM for relatively large Yukawa couplings. However, certain lepton number violating scattering processes involving the right-handed Higgs triplet and the right-handed neutrinos can stay in equilibrium till the electroweak phase transition and can washout the lepton asymmetry generated in the resonant leptogenesis scenario for mass range of WR as indicated by the CMS excess signal. Thus in such a scenario one needs to invoke post-sphaleron baryogenesis to explain the observed baryon asymmetry of the universe. Next, we consider three effective low energy subgroups of the superstring inspired E6 model having a number of additional exotic fermions which provides a rich phenomenology to be explored. We however find that these three effective low energy subgroups of E6 too cannot explain both the eejj excess signal and leptogenesis simultaneously
An exploratory study of Higgs-boson pair production

Higgs-boson pair production is well known being capable to probe the trilinear self-coupling of the Higgs boson, which is one of the important ingredients of the Higgs sector itself. Pair production then depends on the top-quark Yukawa coupling g t S , P , Higgs trilinear coupling λ 3 H , and a possible dim-5 contact-type ttHH coupling g tt S , P , which may appear in some higher representations of the Higgs sector. We take into account the possibility that the top-Yukawa and the ttHH couplings involved can be CP violating. We calculate the cross sections and the interference terms as coefficients of the square or the 4th power of each coupling ( g t S , P , λ 3 H , g tt S , P ) at various stages of cuts, such that the desired cross section under various cuts can be obtained by simply inputing the couplings. We employ the H H → γ γ b b ¯ $$ HH\to \gamma \gamma b\overline{b} $$ decay mode of the Higgs-boson pair to investigate the possibility of disentangle the triangle diagram from the box digram so as to have a clean probe of the trilinear coupling at the LHC. We found that the angular separation between the b and b ¯ $$ \overline{b} $$ and that between the two photons is useful. We obtain the sensitivity reach of each pair of couplings at the 14 TeV LHC and the future 100 TeV pp machine. Finally, we also comment on using the b b ¯ τ + τ − $$ b\overline{b}{\tau}^{+}{\tau}^{-} $$ decay mode in appendix
Convergent Surface Water Distributions in U.S. Cities

Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However, the scope and consequences of surface water redistribution at broad spatial scales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US cities with their surrounding undeveloped land. We evaluated differences in areal (A WB) and numeric densities (N WB) of water bodies (lakes, wetlands, and so on), the morphological characteristics of water bodies (size), and the density (D C) of surface flow channels (that is, streams and rivers). The variance of urban A WB, N WB, and D C across the 100 MSAs decreased, by 89, 25, and 71%, respectively, compared to undeveloped land. These data show that many cities are surface water poor relative to undeveloped land; however, in drier landscapes urbanization increases the occurrence of surface water. This convergence pattern strengthened with development intensity, such that high intensity urban development had an areal water body density 98% less than undeveloped lands. Urbanization appears to drive the convergence of hydrological features across the US, such that surface water distributions of cities are more similar to each other than to their surrounding landscapes. © 2014 The Author(s)
Effective theory approach to new physics in b→u and b→c leptonic and semileptonic decays

Recent measurements of exclusive B-→τ-ν and B0→π+l-ν̄l decays via the b→ulν transition process differ from the standard model expectation and, if they persist in future B experiments, will be a definite hint of the physics beyond the standard model. Similar hints of new physics have been observed in b→c semileptonic transition processes as well. BABAR measures the ratio of branching fractions of B→(D,D*)τν to the corresponding B→(D,D*)lν, where l represents either an electron or a muon, and finds 3.4σ discrepancy with the standard model expectation. In this context, we consider a most general effective Lagrangian for the b→ulν and b→clν transition processes in the presence of new physics and perform a combined analysis of all the b→u and b→c semi-(leptonic) data to explore various new physics operators and their couplings. We consider various new physics scenarios and give predictions for the Bc→τν and B→πτν decay branching fractions. We also study the effect of these new physics parameters on the ratio of the branching ratios of B→πτν to the corresponding B→πlν decays
Speciation Analysis of Mercury in Seawater from the Lagoon of Venice by on-line Pre-concentration HPLC-ICP-MS

A method based on the coupling of HPLC with ICP-MS with an on-line pre-concentration
micro-column has been developed for the analysis of inorganic and methyl mercury in
the dissolved phase of natural waters. This method allows the rapid pre-concentration
and matrix removal of interferences in complex matrices such as seawater with minimal
sampling handling. Detection limits of 0.07 ng L−1 for inorganic mercury and 0.02 ng L−1 for
methyl mercury have been achieved allowing the determination of inorganic mercury and
methyl mercury in filtered seawater fromtheVenice lagoon. Good accuracy and reproducibility
was demonstrated by the repeat analysis of the certified reference material BCR-579
coastal seawater. The developed HPLC separation was shown to be also suitable for the
determination of methyl mercury in extracts of the particulate phase
Study of the chemical composition and the mechanical behaviour of 20th century commercial artists' oil paints containing manganese-based pigments

The present study deals with 20th century manufactured artists' oil paints containing raw \ud
and burnt umber pigments, this is, natural earth pigments resulting from the combination of iron and \ud
manganese oxides. Manganese, in particular, is known to be a primary drier and to have a siccative \ud
effect on oil paint films.\ud
This research aims to show the diversity of formulations behind apparently same commercial names as \ud
well as to understand how the content of manganese, the presence of modern lipidic media and the \ud
hydrolysis mechanisms can promote significant differences in the expected mechanical properties of \ud
oil paint films, thus conditioning their long-term performance. \ud
Several manufactured artists' oil paint films containing manganese were selected. Dried films from \ud
raw and burnt umber oil paints by Winsor&Newton® (UK), Grumbacher® (USA), Gamblin® (USA) and \ud
Speedball® (USA) were studied and information about their chemical composition and mechanical \ud
behaviour is here presented. In addition to the identification and the study of the inorganic and organic \ud
components present in each formulation through LM, SEM-EDX, FTIR-ATR, XRD, GC-MS analysis, \ud
tensile tests were run and stress-strain curves were obtained. Together with evident hue differences, \ud
the obtained results showed significant differences in the chemical composition and the mechanical \ud
behaviour of the oil paint films
Assessing the suitability of student interactions from Moodle data logs as predictors of cross-curricular competencies

In the past decades, online learning has transformed the educational landscape with the emergence of new ways to learn. This fact, together with recent changes in educational policy in Europe aiming to facilitate the incorporation of graduate students to the labor market, has provoked a shift on the delivery of instruction and on the role played by teachers and students, stressing the need for development of both basic and cross-curricular competencies. In parallel, the last years have witnessed the emergence of new educational disciplines that can take advantage of the information retrieved by technology-based online education in order to improve instruction, such as learning analytics.\ud
\ud
This study explores the applicability of learning analytics for prediction of development of two cross-curricular competencies – teamwork and commitment – based on the analysis of Moodle interaction data logs in a Master’s Degree program at Universidad a Distancia de Madrid (UDIMA) where the students were education professionals. The results from the study question the suitability of a general interaction-based approach and show no relation between online activity indicators and teamwork and commitment acquisition. The discussion of results includes multiple recommendations for further research on this topic
Polyoxymethylene additives

This chapter presents a review of the role of several additives on POM processing (lubricating agents, processing aids, nucleating agents), performances (fillers, impact modifiers) and lifetime increase (antioxidants, compounds reacting with secondary reaction products such as acids scavengers, UV stabilizers and flame retardants) and aspect properties (pigments). It is tried to review existing models permitting to describe the efficiency of these additives in POM and predict the effect of other comparable additives that are not included in this review. Last, since POM compounding can be relatively complex and additives are scarcely used alone, it was also tried to report some side effects of these additives and the possible synergistic or antagonistic effects in the case of combinations of additives
Europium retention onto clay minerals from 25 to 150 °C: Experimental measurements, spectroscopic features and sorption modelling

The sorption of Eu(III) onto kaolinite and montmorillonite was investigated up to 150 °C. The clays were purified samples, saturated with Na in the case of montmorillonite. Batch experiments were conducted at 25, 40, 80 and 150 °C in 0.5 M NaClO4 solutions to measure the distribution coefficients (Kd) of Eu as a trace element (<10−6 mol/L) between the solution and kaolinite. For the Na-montmorillonite, we used Kd results from a previous study [Tertre, E., Berger, G., Castet, S., Loubet, M., Giffaut, E., 2005. Experimental study of adsorption of Ni2+, Cs+ and Ln3+ onto Na-montmorillonite up to 150 °C. Geochim. Cosmochim. Acta 69, 4937–4948] obtained under exactly the same conditions. The number and nature of the Eu species sorbed onto both clay minerals were investigated by time resolved laser fluorescence spectroscopy (TRLFS) in specific experiments in the same temperature range. We identified a unique inner-sphere complex linked to the aluminol sites in both clays, assumed to be double bond; length as m-dashAlOEu2+ at the edge of the particles, and a second exchangeable outer-sphere complex for montmorillonite, probably in an interlayer position. The Kd values were used to adjust the parameters of a surface complexation model (DLM: diffuse layer model) from 25 to 150 °C. The number of Eu complexes and the stoichiometry of reactions were constrained by TRLFS. The acidity constants of the amphoteric aluminol sites were taken from another study [Tertre, E., Castet, S., Berger, G., Loubet, M., Giffaut, E. Acid/base surface chemistry of kaolinite and Na-montmorillonite at 25 and 60 °C: experimental study and modelling. Geochim. Cosmochim. Acta, in press], which integrates the influence of the negative structural charge of clays on the acid/base properties of edge sites as a function of temperature and ionic strength. The results of the modelling show that the observed shift of the sorption edge towards low pH with increasing temperature results solely from the contribution of the double bond; length as m-dashAlOEu2+ edge complexes. Finally, we successfully tested the performance of our model by confronting the predictions with experimental Kd data. We used our own data obtained at lower ionic strength (previous study) or higher suspension density and higher starting concentration (TRLFS runs, this study), as well as published data from other experimental studies [Bradbury, M.H., Baeyens, B., 2002. Sorption of Eu on Na and Ca-montmorillonite: experimental investigations and modeling with cation exchange and surface complexation. Geochim. Cosmochim. Acta 66, 2325–2334; Kowal-Fouchard, A., 2002. Etude des mécanismes de rétention des ions U(IV) et Eu(III) sur les argiles: influence des silicates. Ph.D. Thesis, Université Paris Sud, France, 330p]
First determination of the (re)crystallization activation energy of an irradiated olivine-type silicate

To study the evolution of silicate dust in different astrophysical environments we simulate, in the laboratory, interstellar and circumstellar ion irradiation and thermal annealing processes. An experimental protocol that follows different steps in the dust life-cycle was developed. Using the silicate 10 $\mu$m band as an indicator, the evolution of the structural properties of an ion-irradiated olivine-type silicate sample, as a function of temperature, is investigated and an activation energy for crystallization is determined. The obtained value of ${E_{\rm a}}/k$ = 41 700 $\pm$ 2400 K is in good agreement with previous determinations of the activation energies of crystallization reported for non-ion-irradiated, amorphous silicates. This implies that the crystallization process is independent of the history of the dust. In particular, the defect concentration due to irradiation appears not to play a major role in stimulating, or hindering, crystallization at a given temperature. This activation energy is an important thermodynamical parameter that must be used in theoretical models which aim to explain the dust evolution from its place of birth in late type stars to its incorporation into young stellar environments, proto-stellar discs and proto-planetary systems after long passage through the interstellar medium
The Semantics of dialogue

International audienceThe semantics of dialogue is a fundamental topic for a number of reasons. First, dialogue is the primary medium of language use, phylogenetically and ontogenetically. Second, studying dialogue forces one to a particularly careful study of the nature of context. The context has a role to play in determining what one can or should say at a given point and also how to say it. Conversely, it affords the interlocutors a very impressive economy of expression – there is much subtlety that can be achieved with relatively little effort drawing simply on material that is in the context. Consequently, two themes will drive this article, relating to two fundamental problems a semantic analysis in dialogue has to tackle: (1) Conversational relevance: given that a conversation is in a certain state, what utterances can be produced coherently by each conversational participant in that state? Conversational meaning: what conversational states are appropriate for a given word/construction and what import will that word have in such a state