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See detailOn the importance of the 1-loop finite corrections to seesaw neutrino masses.
Aristizabal Sierra, Diego ULg; Yaguna, Carlos

in Journal of High Energy Physics [=JHEP] (2011)

In the standard seesaw mechanism, finite corrections to the neutrino mass matrix arise from 1-loop self-energy diagrams mediated by a heavy neutrino. We study in detail these corrections and demonstrate ... [more ▼]

In the standard seesaw mechanism, finite corrections to the neutrino mass matrix arise from 1-loop self-energy diagrams mediated by a heavy neutrino. We study in detail these corrections and demonstrate that they can be very significant, exceeding in several cases the tree-level result. We consider the normal and inverted hierarchy spectra for light neutrinos and compute the finite corrections to the different elements of the neutrino mass matrix. Special attention is paid to their dependence with the parameters of the seesaw model. Among the cases in which the corrections can be large, we identify the fine-tuned models considered previously in the literature, where a strong cancellation between the different parameters is required to achieve compatibility with the experimental data. As a particular example, we also analyze how these corrections modify the tribimaximal mixing pattern and find that the deviations may be sizable, in particular for θ13. Finally, we emphasize that due to their large size, the finite corrections to neutrino masses have to be taken into account if one wants to properly scan the parameter space of seesaw models. [less ▲]

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See detailOn the increasing relevance of time in later Late Egyptian: jw sDm=f and jw jw=f r sDm, and other things
Winand, Jean ULg

in Lingua Aegyptia [= LingAeg] (2015), 22

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See detailON THE INFLUENCE OF A NON-LOCAL ELECTRODYNAMICS IN THE IRREVERSIBLE MAGNETIZATION OF NON-MAGNETIC BOROCARBIDES
Silhanek, Alejandro ULg; Civale, L.; Thompson, J.R. et al

in Annett, James F.; Kruchinin, Sergei (Eds.) New Trends in Superconductivity (2002)

We present an overview of the temperature, field and angular dependence of the irreversible magnetization of non-magnetic borocarbides (Y;Lu)Ni2B2C.We show that nonlocal electrodynamics influences pinning ... [more ▼]

We present an overview of the temperature, field and angular dependence of the irreversible magnetization of non-magnetic borocarbides (Y;Lu)Ni2B2C.We show that nonlocal electrodynamics influences pinning via the unusual behavior of the shear modulus in non-hexagonal lattices. On top of that, we observe that the pinning force density Fp exhibits a rich anisotropic behavior that sharply contrasts with its small mass anisotropy. When H⊥c, Fp is much larger and has a quite different H dependence, indicating that other pinning mechanisms are present. [less ▲]

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See detailOn the influence of aluminium and silicon contents on the kinetics of bainite transformation of intercritical austenite
Mertens, Anne ULg; Jacques, Pascal J.; Zhao, Lie et al

Conference (2002, June)

TRIP-assisted steels show enhanced mechanical properties thanks to the strain-induced transformation of retained austenite to martensite (TRIP effect). Stabilization of austenite is made possible by the ... [more ▼]

TRIP-assisted steels show enhanced mechanical properties thanks to the strain-induced transformation of retained austenite to martensite (TRIP effect). Stabilization of austenite is made possible by the combination of appropriate chemical composition (containing classically high levels of silicon, or, as developed more recently, aluminium) and of a two-steps heat treatment comprising an intercritical annealing followed by an isothermal holding in the bainite formation range. A detailed understanding of the effects of both elements on the bainite transformation kinetics is thus of primary importance for the optimization of austenite retention. The present study aims at a better knowledge of the influence of aluminium levels on the kinetics of the bainite transformation of intercritical austenite, as compared to the effect of silicon. The bainite transformation kinetics was followed by dilatometry in a set of 6 steel grades with varying aluminium and silicon contents. These dilatometry experiments were coupled with a characterization of the microstructures by X-ray diffraction, SEM and image analysis in order to assess the occurrence of an incomplete reaction phenomenon. It was shown that aluminium has a less pronounced effect than silicon in retarding the bainite transformation. A model was proposed to account for this retarding effect as a function of aluminium or silicon contents. [less ▲]

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See detailOn the influence of aluminium and silicon contents on the kinetics of bainite transformation of intercritical austenite
Mertens, Anne ULg; Jacques, Pascal J.; Zhao, Lie et al

in Journal de Physique IV (2003), 112

TRIP-assisted steels show enhanced mechanical properties thanks to the strain-induced transformation of retained austenite to martensite (TRIP effect). Stabilisation of austenite is made possible by the ... [more ▼]

TRIP-assisted steels show enhanced mechanical properties thanks to the strain-induced transformation of retained austenite to martensite (TRIP effect). Stabilisation of austenite is made possible by the combination of appropriate chemical composition (containing classically high levels of silicon, or, as developed more recently, aluminium) and of a two-steps heat treatment comprising an intercritical annealing followed by an isothermal holding in the bainite formation range. A detailed understanding of the effects of both elements on the bainite transformation kinetics is thus of primary importance for the optimisation of austenite retention. The present study aims at a better knowledge of the influence of aluminium levels on the kinetics of the bainite transformation of intercritical austenite, as compared to the effect of silicon. The bainite transformation kinetics was followed by dilatometry in a set of 6 steel grades with varying aluminium and silicon contents. These dilatometry experiments were coupled with a characterisation of the microstructures by X-ray diffraction, SEM and image analysis. It was shown that aluminium has a less pronounced effect than silicon in retarding the bainite transformation [less ▲]

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See detailOn the influence of aluminium content on the stability of retained austenite in multiphase TRIP-assisted steels
Mertens, Anne ULg; Jacques, Pascal J.; Lazarova, Roumiana et al

in Journal de Physique IV (2001), 11

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See detailOn the influence of aluminium content on the stability of retained austenite in multiphase TRIP-assisted steels
Mertens, Anne ULg; Jacques, Pascal J.; Lazarova, Roumiana et al

Poster (2000, September)

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See detailOn the influence of background component in resonance of cables
Canor, Thomas ULg; Denoël, Vincent ULg

in 9th International Symposium on Cable Dynamics: ISCD 2011, Proceedings (2011)

This work deals with nonlinear dynamical behaviour of cables in the context of random excitations of one of its anchors. Different studies have already been realized, that highlight different cable ... [more ▼]

This work deals with nonlinear dynamical behaviour of cables in the context of random excitations of one of its anchors. Different studies have already been realized, that highlight different cable responses under random excitations such as white noise or narrow band processes. This work can be seen as an extension of these former works. It aims at modeling a more realistic random excitation by associating a background component to a resonant excitation. The background component models the effects of turbulence on the structure and the resonant component results from structural vibrations of the primary system. Any direct excitation on the cable is disregarded in this work. The first part of this paper describes the model and the random excitation generators. The second part deals with the influence of the background component on the possible resonance of a cable. Results are presented for a given level of energy in the excitation, and as a function of its dispatching between the background and resonant components. This work shows that the background component reduces the vibration in the out-of-plane mode and can avoid resonance from taking place. The on-off intermittency phenomenon is also observed for the out-of-plane mode and it depends also on the background component. [less ▲]

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See detailOn the Influence of Blends on the Potential of Ground-based Transit Surveys
Gillon, Michaël ULg; Magain, Pierre ULg

in Afonso, C.; Weldrake, D.; Henning, T. (Eds.) Transiting Extrapolar Planets Workshop (2007, July 01)

Transit surveys have to observe many stars all at once in order to compensate for the rarity of the searched events. Such surveys, especially the ones observing a deep field of view and/or broadening ... [more ▼]

Transit surveys have to observe many stars all at once in order to compensate for the rarity of the searched events. Such surveys, especially the ones observing a deep field of view and/or broadening their stellar images, have to deal with a relatively high level of crowding. This crowding could lead to a reduction of the number of detectable transits, and the estimation of the potential of such surveys without taking into account the influence of blends could give overoptimistic results. We have developed a code which allows to estimate the extent by which such a survey is affected by the crowding of the field of view. Our results show that the influence of blends is important only for severe levels of crowding and is in general much less crucial than the influence of red noise. [less ▲]

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See detailOn the influence of indenter tip geometry on the identification of material parameters in indentation testing
Guo, Weichao ULg

Doctoral thesis (2010)

The rapid development of structural materials and their successful applications in various sectors of industry have led to increasing demands for assessing their mechanical properties in small volumes. If ... [more ▼]

The rapid development of structural materials and their successful applications in various sectors of industry have led to increasing demands for assessing their mechanical properties in small volumes. If the size dimensions are below micron, it is difficult to perform traditional tensile and compression tests at such small scales. Indentation testing as one of the advanced technologies to characterize the mechanical properties of material has already been widely employed since indentation technology has emerged as a cost-effective, convenient and non-destructive method to solve this problem at micro- and nanoscales. In spite of the advances in indentation testing, the theory and development on indentation testing are still not completely mature. Many factors affect the accuracy and reliability of identified material parameters. For instance, when the material properties are determined utilizing the inverse analysis relying on numerical modelling, the procedures often suffer from a strong material parameter correlation, which leads to a non-uniqueness of the solution or high errors in parameter identification. In order to overcome that problem, an approach is proposed to reduce the material parameter correlation by designing appropriate indenter tip shapes able to sense indentation piling-up or sinking-in occurring in non-linear materials. In the present thesis, the effect of indenter tip geometry on parameter correlation in material parameter identification is investigated. It may be helpful to design indenter tip shapes producing a minimal material parameter correlation, which may help to improve the reliability of material parameter identification procedures based on indentation testing combined with inverse methods. First, a method to assess the effect of indenter tip geometry on the identification of material parameters is proposed, which contains a gradient-based numerical optimization method with sensitivity analysis. The sensitivities of objective function computed by finite difference method and by direct differentiation method are compared. Subsequently, the direct differentiation method is selected to use because it is more reliable, accurate and versatile for computing the sensitivities of the objective function. Second, the residual imprint mappings produced by different indenters are investigated. In common indentation experiments, the imprint data are not available because the indenter tip itself shields that region from access by measurement devices during loading and unloading. However, they include information about sinking-in and piling-up, which may be valuable to reduce the correlation of material parameter. Therefore, the effect of the imprint data on identification of material parameters is investigated. Finally, some strategies for improvement of the identifiability of material parameter are proposed. Indenters with special tip shapes and different loading histories are investigated. The sensitivities of material parameters toward indenter tip geometries are evaluated on the materials with elasto-plastic and elasto-visoplastic constitutive laws. The results of this thesis have shown that first, the correlations of material parameters are related to the geometries of indenter tip shapes. The abilities of different indenters for determining material parameters are significantly different. Second, residual imprint mapping data are proved to be important for identification of material parameters, because they contain the additional information about plastic material behaviour. Third, different loading histories are helpful to evaluate the material parameters of time-dependent materials. Particularly, a holding cycle is necessary to determine the material properties of time-dependent materials. These results may be useful to enable a more reliable material parameter identification. [less ▲]

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See detailOn the influence of misclassified data on results of goodness of fit testing
Magis, David ULg

in Statistical Methodology (2005), 2

In this paper we focus on the chi-square test of goodness of fit, which compares an observed discrete distribution to an expected known one. We show that the results of this test, using the common Pearson ... [more ▼]

In this paper we focus on the chi-square test of goodness of fit, which compares an observed discrete distribution to an expected known one. We show that the results of this test, using the common Pearson statistic, are very sensitive to misclassified observations between two or more categories. We also propose a general rule of thumb for analysing data set stability with respect to such classification errors. Practical analysis of a real example illustrates our purpose. [less ▲]

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See detailOn the influence of the disturbed conditions in the centrifugal concentration of heavy fine particles
Patchejieff, B.; Gaydardzhiev, Stoyan ULg; Stoev, S.

in Ozbayoglu, G. (Ed.) Proceedings of the 8-th IMPS Antalya, Turkey, 16-18 X 2000, 167-170 (2000)

Model investigations were carried out with the aim to improve the method for accelerated gravity separation of heavy fine mineral particles. The effects of feed particle size has been studied with the aim ... [more ▼]

Model investigations were carried out with the aim to improve the method for accelerated gravity separation of heavy fine mineral particles. The effects of feed particle size has been studied with the aim to generate disturbed conditions inside the riffle zones of a bowl-type centrifuge and thus to avoid material packing leading to better separation conditions. [less ▲]

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See detailOn the influence of transuranium dilution in well known U heavy fermion compounds
Wastin, Frank; Zwirner, Stefan; Seret, Alain ULg et al

Poster (1995, September)

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See detailOn the influence of transuranium dilution in well-known U heavy-fermion compounds
Wastin, Frank; Zwirner, Stefan; Seret, Alain ULg et al

in Physica B: Condensed Matter (1996), 223-224

Synthesis and preliminary studies on U1−xNpxPd2Al3 and U1−xNpxRu2Si2 are presented. In all Np compounds measured here, no superconducting transition was found down to 1.4 K. In U1−xNpxPd2Al3 a small ... [more ▼]

Synthesis and preliminary studies on U1−xNpxPd2Al3 and U1−xNpxRu2Si2 are presented. In all Np compounds measured here, no superconducting transition was found down to 1.4 K. In U1−xNpxPd2Al3 a small amount (0.01 less-than-or-equals, slant x less-than-or-equals, slant 0.05) of Np induces an anomaly in the lattice parameters and presents in resistivity measurements a sharp minimum at low temperature. [less ▲]

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See detailOn the integration of the equation of radiative transfer.
Swings, Polydore ULg; Dor, L.

in Astrophysical Journal (1938), 88(4), 516-521

The equation of the radiative transfer has been integrated by a generalization of Spitzer's method, which makes use of Bessel functions.

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See detailOn the intensity distribution in the bands of cometary spectra.
Swings, Polydore ULg; Nicolet, M.

in Astrophysical Journal (1938), 88(2), 173-181

The exceptional intensity distribution of bands of unsymmetrical molecules like CN and CH in a comet spectra can be explained by taking into consideration the following factors: (a) the frequency of ... [more ▼]

The exceptional intensity distribution of bands of unsymmetrical molecules like CN and CH in a comet spectra can be explained by taking into consideration the following factors: (a) the frequency of electronic absorption processes; (b) the distribution in the vibrational levels (ground state) which is a function of the nuclear temperature TI or of the equivalent radiation temperature Tλ; (c) the distribution in the rotational levels corresponding to the nuclear temperature. These factors are different functions of the heliocentric distance r. [less ▲]

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See detailOn the Intercostal Muscle Compensation for Diaphragmatic Paralysis in the Dog
Brichant, Jean-François ULg; De Troyer, A.

in Journal of Physiology (1997), 500((Pt 1)), 245-53

1. Paralysis of the diaphragm in the dog is known to cause a compensatory increase in activation of the inspiratory intercostal muscles (parasternal intercostals, external intercostals, and levator costae ... [more ▼]

1. Paralysis of the diaphragm in the dog is known to cause a compensatory increase in activation of the inspiratory intercostal muscles (parasternal intercostals, external intercostals, and levator costae). The present studies were designed to assess the mechanism(s) of that compensation. 2. Complete, selective diaphragmatic paralysis was induced by injecting local anaesthetic into small silicone cuffs placed around the phrenic nerve roots in the neck. 3. Paralysis produced a decrease in tidal volume and an increase in arterial P(CO2) (P(a,CO2)). The increased hypercapnic drive was a primary determinant of the increased inspiratory intercostal activity. 4. However, paralysis also produced an increased inspiratory cranial displacement of the ribs. When this increased rib displacement was reduced to that seen before paralysis, it appeared that the increase in external intercostal and levator costae inspiratory activity was commonly greater than anticipated on the basis of the increased P(a,CO2). 5. Diaphragmatic paralysis after bilateral vagotomy also elicited disproportionate increases in inspiratory intercostal activity, thus indicating that these increases are not caused by vagal afferent inputs. 6. These observations are consistent with the idea that the intercostal muscle compensation for diaphragmatic paralysis is, in part, due to the release of an inhibition originating from the contracting diaphragm. This inhibition might arise in the diaphragmatic tendon organs. [less ▲]

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See detailOn the interpretation of serial laboratory measurements in acute myocardial infarction.
Albert, Adelin ULg; Harris, E. K.; CHAPELLE, Jean-Paul ULg et al

in Clinical Chemistry (1984), 30(1), 69-76

Serial laboratory determinations are now routinely performed on patients admitted to intensive-care units. Adequate interpretation of such cumulative information for clinical decision-making purposes is a ... [more ▼]

Serial laboratory determinations are now routinely performed on patients admitted to intensive-care units. Adequate interpretation of such cumulative information for clinical decision-making purposes is a challenging problem. We describe a statistical method for predicting--sequentially as the data become available--the patient's outcome, death or survival. Thus, the method goes beyond previously reported techniques that base such prediction on only a single multivariate observation. The method has been applied to daily measurements of serum urea and lactate dehydrogenase, performed during one week on patients hospitalized in the coronary-care unit with acute myocardial infarction. Two baseline variables were also included in the dynamic risk index so derived: the age of the patient and the number of previous myocardial infarctions recorded on admission. We also discuss the problems of selecting the most-predictive laboratory tests and of determining for each test the amount of past data needed to achieve satisfactory prediction. We distinguish between global evaluation of the dynamic risk index obtained (in terms of specificity and sensitivity) and individual interpretation (in terms of posterior/prior probability ratio) of a given risk score for a particular patient. The approach described may contribute to more effective use of results of repeated laboratory tests on critically ill patients. [less ▲]

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