Sart Tilman

Liège, Belgium

Sart Tilman

Liège, Belgium
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Durel C.-A.,Edouard Herriot Hospital | Aouba A.,Cote Of Nacre Hospital | Bienvenu B.,Cote Of Nacre Hospital | Deshayes S.,Cote Of Nacre Hospital | And 26 more authors.
Medicine (United States) | Year: 2016

The aim of this study was to describe the clinical and biological features of Mevalonate kinase deficiency (MKD) in patients diagnosed in adulthood. This is a French and Belgian observational retrospective study from 2000 to 2014. To constitute the cohort, we cross-check the genetic and biochemical databases. The clinical, enzymatic, and genetic data were gathered from medical records. Twenty-three patients were analyzed. The mean age at diagnosis was 40 years, with a mean age at onset of symptoms of 3 years. All symptomatic patients had fever. Febrile attacksweremostly associated with arthralgia (90.9%); lymphadenopathy, abdominal pain, and skin lesions (86.4%); pharyngitis (63.6%); cough (59.1%); diarrhea, and hepatosplenomegaly (50.0%). Seven patients had psychiatric symptoms (31.8%). One patient developed recurrent seizures. Three patients experienced renal involvement (13.6%). Two patients had angiomyolipoma (9.1%). All but one tested patients had elevated serum immunoglobulin (Ig) D level. Twenty-one patients had genetic diagnosis; most of them were compound heterozygote (76.2%). p.Val377Ile was themost prevalent mutation. Structural articular damages and systemic AAamyloidosis were the 2 most serious complications.More than 65% of patients displayed decrease in severity and frequency of attacks with increasing age, but only 35% achieved remission. MKD diagnosed in adulthood shared clinical and genetic features with classical pediatric disease. An elevated IgD concentration is a good marker for MKD in adults. Despite a decrease of severity and frequency of attacks with age, only one-third of patients achieved spontaneous remission. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.


Zou J.,University of Cambridge | Ainslie M.D.,University of Cambridge | Fujishiro H.,Iwate University | Bhagurkar A.G.,Brunel University | And 5 more authors.
Superconductor Science and Technology | Year: 2015

MgB2 in bulk form shows great promise as trapped field magnets (TFMs) as an alternative to bulk (RE)BCO materials to replace permanent magnets in applications such as rotating machines, magnetic bearings and magnetic separation, and the relative ease of fabrication of MgB2 materials has enabled a number of different processing techniques to be developed. In this paper, a comparison is made between bulk MgB2 samples fabricated by the hot isostatic pressing (HIP), with and without Ti-doping, and infiltration growth (IG) methods and the highest trapped field in an IG-processed bulk MgB2 sample, Bz = 2.12 at 5 K and 1.66 T at 15 K, is reported. Since bulk MgB2 has a more homogeneous Jc distribution than (RE)BCO bulks, studies on such systems are made somewhat easier because simplified assumptions regarding the geometry and Jc distribution can be made, and a numerical simulation technique based on the 2D axisymmetric H-formulation is introduced to model the complete process of field cooling (FC) magnetization. As input data for the model, the measured Jc(B,T) characteristics of a single, small specimen taken from each bulk sample are used, in addition to measured specific heat and thermal conductivity data for the materials. The results of the simulation reproduce the experimental results extremely well: (1) indicating the samples have excellent homogeneity, and (2) validating the numerical model as a fast, accurate and powerful tool to investigate the trapped field profile of bulk MgB2 discs of any size accurately, under any specific operating conditions. Finally, the paper is concluded with a numerical analysis of the influence of the dimensions of the bulk sample on the trapped field. © 2015 IOP Publishing Ltd.


Zou J.,University of Cambridge | Ainslie M.D.,University of Cambridge | Fujishiro H.,Iwate University | Bhagurkar A.G.,Brunel University | And 5 more authors.
Superconductor Science and Technology | Year: 2015

MgB2 in bulk form shows great promise as trapped field magnets (TFMs) as an alternative to bulk (RE)BCO materials to replace permanent magnets in applications such as rotating machines, magnetic bearings and magnetic separation, and the relative ease of fabrication of MgB2 materials has enabled a number of different processing techniques to be developed. In this paper, a comparison is made between bulk MgB2 samples fabricated by the hot isostatic pressing (HIP), with and without Ti-doping, and infiltration growth (IG) methods and the highest trapped field in an IG-processed bulk MgB2 sample, Bz = 2.12 at 5 K and 1.66 T at 15 K, is reported. Since bulk MgB2 has a more homogeneous Jc distribution than (RE)BCO bulks, studies on such systems are made somewhat easier because simplified assumptions regarding the geometry and Jc distribution can be made, and a numerical simulation technique based on the 2D axisymmetric H-formulation is introduced to model the complete process of field cooling (FC) magnetization. As input data for the model, the measured Jc(B,T) characteristics of a single, small specimen taken from each bulk sample are used, in addition to measured specific heat and thermal conductivity data for the materials. The results of the simulation reproduce the experimental results extremely well: (1) indicating the samples have excellent homogeneity, and (2) validating the numerical model as a fast, accurate and powerful tool to investigate the trapped field profile of bulk MgB2 discs of any size accurately, under any specific operating conditions. Finally, the paper is concluded with a numerical analysis of the influence of the dimensions of the bulk sample on the trapped field. © 2015 IOP Publishing Ltd.


Vadnais M.-E.,University of Quebec at Trois - Rivieres | Assani A.A.,University of Quebec at Trois - Rivieres | Hallot E.,University of Liège | Petit F.,Sart Tilman
Revue des Sciences de l'Eau | Year: 2011

The goal of this study was to determine which environmental factors affect the spatial variability of annual minimum streamflow characteristics for 34 rivers in Wallonia (Belgium) using two complementary methods: the ascending hierarchical classification method and the linear correlation method. Both methods were applied after principal component analysis transformation was applied to the data. The ascending hierarchical classification method (Ward's method) identified the effect of lithology and anthropogenic activity (groundwater pumping) on the fundamental characteristics of annual minimum flows. Rivers that drain a relatively permeable substrate are characterized by very high flow volumes with low interannual variability, high interannual variability of the period of occurrence, and small asymmetry coefficients. Rivers that drain low permeability or impermeable substrates show the opposite patterns. Rivers in which flow is subjected to artificial influences are characterized by greater variability of the magnitude and of the period of occurrence of annual minimum flows than natural rivers. Analysis of linear correlations between streamflow characteristics and environmental factors highlighted a correlation between the form of the distribution curves of annual minimum flows and several environmental factors (climate, land use, location and physiographic characteristics of the watersheds).


PubMed | Sart Tilman and University of Cambridge
Type: Journal Article | Journal: The Review of scientific instruments | Year: 2015

We report the design and construction of a flux extraction device to measure the DC magnetic moment of large samples (i.e., several cm(3)) at cryogenic temperature. The signal is constructed by integrating the electromotive force generated by two coils wound in series-opposition that move around the sample. We show that an octupole expansion of the magnetic vector potential can be used conveniently to treat near-field effects for this geometrical configuration. The resulting expansion is tested for the case of a large, permanently magnetized, type-II superconducting sample. The dimensions of the sensing coils are determined in such a way that the measurement is influenced by the dipole magnetic moment of the sample and not by moments of higher order, within user-determined upper bounds. The device, which is able to measure magnetic moments in excess of 1 A m(2) (1000 emu), is validated by (i) a direct calibration experiment using a small coil driven by a known current and (ii) by comparison with the results of numerical calculations obtained previously using a flux measurement technique. The sensitivity of the device is demonstrated by the measurement of flux-creep relaxation of the magnetization in a large bulk superconductor sample at liquid nitrogen temperature (77 K).

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