pinecone/core-2020-05-10-deduplication huggingface dataset:
Semiconductor optical ampliﬁer-based heterodyning detection for resolving optical terahertz beat-tone signals from passively mode-locked semiconductor lasers

An all-optical heterodyne approach based on a room-temperature controlled semiconductor optical amplifier (SOA) for measuring the frequency and linewidth of the terahertz beat-tone signal from a passively mode-locked laser is proposed. Under the injection of two external cavity lasers, the SOA acts as a local oscillator at their detuning frequency and also as an optical frequency mixer whose inputs are the self-modulated spectrum of the device under test and the two laser beams. Frequency and linewidth of the intermediate frequency signal and therefore, the beat-tone signal are resolved by using a photodiode and an electrical spectrum analyze
Building Integration of Aerogel Glazings

The recent building practices have shown that aerogel glazings can be used as a multifunctional building envelope component for different purposes. Nevertheless, the distinctive physical properties and energy performance of aerogel glazings suggest that building integration of aerogel glazings may create architectural challenges, aesthetic problems, as well as concerns on their durability and environmental impact, thus highlighting the importance of developing guidelines to regulate the use of aerogel glazings in the building sector. This study discusses various approaches for the building integration of aerogel glazings by presenting a number of successful examples; the advantages of integration are quantified and suggestions are given to address the possible challenges.© 2016  The Authors. Published  by Elsevier Ltd. This is an open access article under the CC BY-NC-N
Magnetic microstructure and magnetotransport in Co2FeAl Heusler compound
  thin films

We correlate simultaneously recorded magnetotransport and spatially resolved
magneto optical Kerr effect (MOKE) data in Co2FeAl Heusler compound thin films
micropatterned into Hall bars. Room temperature MOKE images reveal the
nucleation and propagation of domains in an externally applied magnetic field
and are used to extract a macrospin corresponding to the mean magnetization
direction in the Hall bar. The anisotropic magnetoresistance calculated using
this macrospin is in excellent agreement with magnetoresistance measurements.
This suggests that the magnetotransport in Heusler compounds can be adequately
simulated using simple macrospin models, while the magnetoresistance
contribution due to domain walls is of negligible importance
Condensation of helium in nanoscopic alkali wedges at zero temperature

We present a complete calculation of the structure of liquid $^4$He confined
to a concave nanoscopic wedge, as a function of the opening angle of the walls.
This is achieved within a finite-range density functional formalism. The
results here presented, restricted to alkali metal substrates, illustrate the
change in meniscus shape from rather broad to narrow wedges on weak and strong
alkali adsorbers, and relate this change to the wetting behavior of helium on
the corresponding planar substrate. As the wedge angle is varied, we find a
sequence of stable states that, in the case of cesium, undergo one filling and
one emptying transition at large and small openings, respectively. A
computationally unambiguous criterion to determine the contact angle of $^4$He
on cesium is also proposed
Linearized Einstein theory via null surfaces

Recently there has been developed a reformulation of General Relativity -
referred to as {\it the null surface version of GR} - where instead of the
metric field as the basic variable of the theory, families of three-surfaces in
a four-manifold become basic. From these surfaces themselves, a conformal
metric, conformal to an Einstein metric, can be constructed. A choice of
conformal factor turns them into Einstein metrics. The surfaces are then
automatically characteristic surfaces of this metric. In the present paper we
explore the linearization of this {\it null surface theory} and compare it with
the standard linear GR. This allows a better understanding of many of the
subtle mathematical issues and sheds light on some of the obscure points of the
null surface theory. It furthermore permits a very simple solution generating
scheme for the linear theory and the beginning of a perturbation scheme for the
full theory.Comment: 22 page
Hamilton formalism in non-commutative geometry

We study the Hamilton formalism for Connes-Lott models, i.e., for Yang-Mills theory in non-commutative geometry. The starting point is an associative *-algebra \cA which is of the form \cA=C(I,\cAs) where \cAs is itself a associative *-algebra. With an appropriate choice of a k-cycle over \cA it is possible to identify the time-like part of the generalized differential algebra constructed out of \cA. We define the non-commutative analogue of integration on space-like surfaces via the Dixmier trace restricted to the representation of the space-like part \cAs of the algebra. Due to this restriction it possible to define the Lagrange function resp.~Hamilton function also for Minkowskian space-time. We identify the phase-space and give a definition of the Poisson bracket for Yang-Mills theory in non-commutative geometry. This general formalism is applied to a model on a two-point space and to a model on Minkowski space-time \times two-point space
On Semi-implicit Splitting Schemes for the Beltrami Color Image Filtering

The Beltrami flow is an efficient nonlinear filter,
that was shown to be effective for color image processing.
The corresponding anisotropic diffusion operator strongly
couples the spectral components. Usually, this flow is implemented
by explicit schemes, that are stable only for
very small time steps and therefore require many iterations.
In this paper we introduce a semi-implicit Crank-Nicolson
scheme based on locally one-dimensional (LOD)/additive
operator splitting (AOS) for implementing the anisotropic
Beltrami operator. The mixed spatial derivatives are treated
explicitly, while the non-mixed derivatives are approximated in an implicit manner. In case of constant coefficients, the
LOD splitting scheme is proven to be unconditionally stable.
Numerical experiments indicate that the proposed scheme
is also stable in more general settings. Stability, accuracy,
and efficiency of the splitting schemes are tested in applications
such as the Beltrami-based scale-space, Beltrami denoising
and Beltrami deblurring. In order to further accelerate
the convergence of the numerical scheme, the reduced
rank extrapolation (RRE) vector extrapolation technique is
employed
Determination of S-curves with applications to the theory of nonhermitian orthogonal polynomials

This paper deals with the determination of the S-curves in the theory of non-hermitian orthogonal polynomials with respect to exponential weights along suitable paths in the complex plane. It is known that the corresponding complex equilibrium potential can be written as a combination of Abelian integrals on a suitable Riemann surface whose branch points can be taken as the main parameters of the problem. Equations for these branch points can be written in terms of periods of Abelian differentials and are known in several equivalent forms. We select one of these forms and use a combination of analytic an numerical methods to investigate the phase structure of asymptotic zero densities of orthogonal polynomials and of asymptotic eigenvalue densities of random matrix models. As an application we give a complete description of the phases and critical processes of the standard cubic model
Observed degradation in photovoltaic plants affected by hot-spots

A number of findings have shown that the test procedures currently available to determine the reliability and durability of photovoltaic (PV) modules are insufficient to detect certain problems. To improve these procedures, ongoing research into the actual performance of the modules in the field is required. However, scientific literature contains but few references to field studies of defective modules. This article studies two different localized heating phenomena affecting the PV modules of two large-scale PV plants in Spain. The first problem relates to weak solder joints whilst the second is due to microcracks on the module cells. For both cases, the cause is identified, and consideration is given with regard to the effect on performance, the potential deterioration over time, and a way to detect the problems identified. The findings contained in this paper will prove to be of considerable interest to maintenance personnel at large-scale PV plants and also to those responsible for setting module quality standards and specifications, and even the PV module manufacturers themselves
Intensity-modulated radiotherapy for lung cancer: current status and future developments

Radiotherapy plays an important role in the management of lung cancer, with over 50% of patients receiving this modality at some point during their treatment. Intensity-modulated radiotherapy (IMRT) is a technique that adds fluence modulation to beam shaping, which improves radiotherapy dose conformity around the tumor and spares surrounding normal structures. Treatment with IMRT is becoming more widely available for the treatment of lung cancer, despite the paucity of high level evidence supporting the routine use of this more resource intense and complex technique. In this review article, we have summarized data from planning and clinical studies, discussed challenges in implementing IMRT, and made recommendations on the minimum requirements for safe delivery of IMRT
Cosmological Perturbations in the Projectable Version of Horava-Lifshitz
  Gravity

We consider linear perturbations about a homogeneous and isotropic
cosmological background in the projectable version of Ho\v{r}ava-Lifshitz
gravity. Starting from the action for cosmological perturbations, we identify
the canonically normalized fluctuation variables. We find that - in contrast to
what happens in the non-projectable version of the theory - the extra scalar
cosmological perturbation mode is already dynamical at the level of linear
perturbations. For values of the parameter $\lambda$ in the range $1/3 <
\lambda < 1$, the extra mode is ghost-like, for values $1 < \lambda$ and
$\lambda < 1/3$ it is tachyonic. This indicates a problem for the projectable
version of Ho\v{r}ava-Lifshitz gravity
Semantic primes theory may be helpful in designing questionnaires such as to prevent response shift

International audienceThe purpose of randomized control trials (RCTs) can be the assessment of the direct effect of treatment on health-related quality of life (HRQL). Response shift (RS) theory considers that a change in HRQL scores observed over time cannot be explained solely by a direct effect of a medical condition, it may also result from a change in the way people appraise their HRQL. The RS effect is a potential bias that is liable to compromise efficient assessment of the effect of treatment on HRQL. We hypothesize a link between the RS effect on HRQL scores and the level of complexity of HRQL conceptualization. We discuss how the impact of reconceptualization on scores depends on the complexity of the linguistic definition of a subjective construct and how for reprioritization the impact depends on the dimensionality. The linguistic theory of semantic primes is used to help identify how subjective constructs can be classified according to the complexity of their definitions. Finally, we suggest that the impact of the RS effect on HRQL scores could be avoided (or lessened) if questionnaires were designed with a rule of "the least semantic and psychometric complexity" in mind
Biaxial disclinated states in nematic elastomers

We use a continuum model to investigate the isochoric axial contraction and expansion of a right
circular cylindrical specimen composed of a nematic elastomer that is cross-linked in a uniaxial state
and then annealed. We build on previous work by relaxing the constraint that the molecular
conformation be spherical or uniaxial, allowing instead for biaxiality. The material exhibits an
energetic preference for states involving a disclination of strength 11 along the cylinder axis
surrounded by a region in which the conformation of the polymer chains is indeed biaxial. We show
that such states represent minimizers of the total free-energy. Also, the reactive pressure necessary
to enforce the constraint of material incompressibility within the disclination core is found to be
reduced by an order of magnitude when the conformation is biaxial rather than uniaxial. A
bifurcation analysis is used to analytically determine the thresholds of axial expansion and
contraction at which the material prefers a disclinated state. These thresholds are found to be
consistent with numerical predictions. Finally, the stability of the solutions for the studied
parameters is also investigated.published or submitted for publicationis peer reviewe
Nanostructuration and band gap emission enhancement of ZnO film via electrochemical anodization

International audienceWe report fabrication of nanostructured zinc oxide (ZnO) thin films with improved optical properties through electrochemical anodization. The ZnO films were produced over silicon substrates via radio-frequency (RF) plasma magnetron sputtering technique followed by electrochemical treatment in potassium sulfate solution. After electrochemical treatment, the effect of applied potential on the band gap emission behavior of ZnO films was investigated for the potential drop of 1.8, 2.4 and 3.0 V against reference electrode of Ag/AgCl/0.1 M KCl. Depending on these values, ZnO films with different degrees of nonporous morphology, improved structural quality and oxygen-rich surface chemistry were obtained. The treatment also resulted in enhancement of band gap emission from ZnO films with the degree of enhancement depending on the applied potential. As compared to the as-deposited films, a maximum increase in the photoemission intensity by more than 2.2 times was noticed. In this paper, any changes in the structure, surface chemistry and band gap emission intensity of the RF sputter deposited films, as induced by the anodization treatment at differential potential values, are discussed
Employment suburbanisation, reverse commuting and travel behaviour by residents of the central city in the Paris metropolitan area

International audienceThis paper analyses the relationship between employment suburbanisation in the Paris metropolitan area, the growth of reverse commuting and changes in the weekday travel behaviour of working residents of the central city over a 20 years period. The results show that the number of reverse commuters has significantly increased because the municipality of Paris has lost many jobs but few working residents whilst employment has developed in the suburbs. Reverse commuters are mainly and increasingly high income professionals whose workplace is located close to the central city in employment sub-centres that are well served by public transport. Consequently reverse commuters have lower than average car use although differences exist and are related to their professional status. The policy implications of these findings are discussed in the conclusion
Localizing the latent structure canonical uncertainty: entropy profiles for hidden Markov models

The final publication is available at Springer via http://dx.doi.org/10.1007/s11222-014-9494-9International audienceThis paper addresses state inference for hidden Markov models. These models rely on unobserved states, which often have a meaningful interpretation. This makes it necessary to develop diagnostic tools for quantification of state uncertainty. The entropy of the state sequence that explains an observed sequence for a given hidden Markov chain model can be considered as the canonical measure of state sequence uncertainty. This canonical measure of state sequence uncertainty is not reflected by the classic multidimensional posterior state (or smoothed) probability profiles because of the marginalization that is intrinsic in the computation of these posterior probabilities. Here, we introduce a new type of profiles that have the following properties: (i) these profiles of conditional entropies are a decomposition of the canonical measure of state sequence uncertainty along the sequence and makes it possible to localise this uncertainty, (ii) these profiles are unidimensional and thus remain easily interpretable on tree structures. We show how to extend the smoothing algorithms for hidden Markov chain and tree models to compute these entropy profiles efficiently. The use of entropy profiles is illustrated by sequence and tree data examples
Bidimensional nano-optomechanics and topological backaction in a non-conservative radiation force field

Optomechanics, which explores the fundamental coupling between light and mechanical motion, has made important advances in both exploring and manipulating macroscopic mechanical oscillators down to the quantum level. However, dynamical effects related to the vectorial nature of the optomechanical interaction remain to be investigated. Here we study a nanowire with sub-wavelength dimensions strongly coupled to a tightly focused beam of light, enabling ultrasensitive readout of the nanoresonators dynamics. We experimentally determine the vectorial structure of the optomechanical interaction and demonstrate that bidimensional dynamical backaction governs the nanowire dynamics. Moreover, the non-conservative topology of the optomechanical interaction is responsible for a novel canonical signature of strong coupling between the nanoresonator mechanical modes, leading to a topological instability. These results have a universal character and illustrate the increased sensitivity of nanomechanical devices towards topologically varying interactions, opening fundamental perspectives in nanomechanics, optomechanics, ultrasensitive scanning probe force microscopy and nano-optics
Plasma L-citrulline concentrations and its relationship with inflammation at the onset of septic shock: A pilot study.
 : 
citrulline in septic shock

International audiencePURPOSE: Hypocitrullinemia has been suggested to be a prognostic factor for patients in intensive care. The aim of this ancillary study of the Corticosteroids and Intensive Insulin Therapy for Septic Shock prospective study was to investigate plasma l-citrulline concentrations and its relationship with inflammation and digestive bacterial translocation in patients with septic shock multiorgan failure and without primary intestinal disease or chronic renal failure. METHODS: Sixteen adult patients were selected. They were studied on day (D) 0 at hours (H) 0, 6, 12, 18, and 24 and on D4 (H96). Selected plasma amino acids and proteins, proinflammatory (tumor necrosis factor α [TNF-α]) and anti-inflammatory (interleukin [IL] 10) cytokine concentrations, and bacterial translocation were measured. RESULTS: Eight D14 survivors and 8 D14 nonsurvivors patients were studied. Citrulline was decreased on D0 (H0: 29 ± 10 vs nadir: 18 ± 6 μmol/L; P < .05). The citrulline nadir was lower (P < .01) in patients with digestive bacterial translocation than that in those without. Mean citrulline concentrations at H0 to H96 were not significantly different between survivors and nonsurvivors. In both groups, citrulline was significantly inversely correlated with C-reactive protein (r(2) = 0.10, P < .01) on D0. No significant correlations were found between citrulline and albumin, transthyretin, TNF-α, IL-10, or TNF-α/IL-10 ratio. CONCLUSIONS: At the onset of septic shock, plasma citrulline decreases and varies inversely with C-reactive protein and is lower when digestive bacterial translocation occurs. This finding could reflect an early acute intestinal dysfunction, but measurement of citrulline concentration does not appear to be able to predict the patients' mortality
Riemannian Framework for estimating Symmetric Positive Definite 4th Order Diffusion Tensors

International audienceDTI is an important tool to investigate the brain in vivo and non-invasively in spite of its shortcomings in regions of fiber-crossings. HARDI models such as QBI and Higher Order Tensors (HOT) were in- vented to overcome this shortcoming. HOTs, however, have not been explored extensively even though sophisticated estimation schemes were developed for DTI that guarantee positive diffusivity, such as the Rie- mannian framework. Positive diffusivity is an important constraint in diffusion MRI since it represents the physical phenomenon of molecular diffusion. It seems apt, to leverage the work done on DTI, to apply the positivity constraint to the HOT model. We, therefore, propose to extend the Riemannian framework from DTI to the space of 4th order diffusion tensors. We also review the existing methods for estimating 4th order diffusion tensors and compare all methods on synthetic, phantom and real datasets extensively to test for robustness and speed. Our contributions for extending the Riemannian framework from DTI to estimating 4th order diffusion tensors guarantees positive diffusivity, is robust, is fast, and can be used to discern multiple fiber directions
Highly Explosive 2010 Merapi Eruption: Evidence for Shallow-Level Crustal Assimilation and Hybrid Fluid

International audienceThe processes responsible for the highly explosive events at Merapi, Central Java, Indonesia have been investigated through a petrological, mineralogical and geochemical study of the first-stage tephra and pyroclastic flows sampled in October and November 2010, and second-stage ash sampled shortly after the 5 - 6th November 2010 paroxysmal subplinian eruption. Several chemical and physical parameters suggest that the magma assimilated calc-silicate xenoliths derived from the surrounding carbonate-bearing crust (Javanese limestone). The bulk volcanic samples have highly radiogenic 87Sr/86Sr (0.70571 - 0.70598) ratios that approach the compositional field of material similar to the calc-silicate xenoliths. The 2010 plagioclase phenocrysts from the pyroclastic flow and tephra reveal anorthite cores (up to An94-97) with low FeO contents (≤ 0.8 wt.%), and 18O enrichment (6.5 ‰ δ18O). The major and trace elements of the silicic glasses and phenocrysts (plagioclase, low-Al augite and titanomagnetite), the Sr- isotopic compositions of the bulk samples and plagioclases erupted in 2010 can be explained by complete digestion of the 1998 and 2006 calc-silicate xenoliths. The bulk assimilation proceeded through binary mixing between a calcic melt (representing Crustal Assimilant, CaO up to 10.5 wt.%, CaO/Al2O3 up to 1.2) and the deep source hydrous K-rich melt. Similarly to the 1998 and 2006 calc-silicate xenolith composition, the 2010 Crustal Assimilant is enriched in Mn (MnO up to 0.5 wt.%), Zn, V, Sc contents. In contrast, the hydrous K-rich melt is enriched in volatiles (Cl up to 0.37 wt.%, bulk H2O+CO2 up to 5 ± 1 wt.%), Al2O3, TiO2 and REE contents, consistent with its derivation from deep source. This hydrous K-rich melt may have been saturated with an aqueous Cl-rich fluid at about 200 MPa, a pressure consistent with the level of the crustal assimilation. We estimated that the pre-eruptive basaltic andesite magma assimilated from 15 to 40 wt.% of the calc-silicate crustal material, corresponding to introduction of additional 0.19 to 2.1 Mt of CO2 to the magma. Experimental leaching of the ash samples documents the release of an aqueous fluid enriched in Cl, Na, Ca, Cd, Sb and Zn during the paroxysmal subplinian eruption. The paroxysmal eruption may have been produced by saturation of the pre-eruptive basaltic andesite magma with hybrid aqueous carbonic NaCl-HCl-rich fluid due to bulk assimilation creating elevated partial pressure of CO2 at shallow crustal conditions of about 200 MPa. In contrast, mildly explosive block-and-ash flows (typical Merapi-type) may result from selective assimilation of the carbonate-bearing xenoliths and lower CO2 partial pressure that may not lead to explosive degassing