Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailEthylene polymerization by a high activity MgCl2 supported Ti catalyst in the presence of hydrogen and/or 1-octene
Hindryckx, François; Dubois, Philippe ULg; Jérôme, Robert ULg et al

in Polymer (1998), 39(3), 621-629

This paper presents the results of slurry polymerisation of ethylene that has been initiated by an Al/Ti/Mg-alcohol supported catalyst. Special attention has been paid to the effects of hydrogen, catalyst ... [more ▼]

This paper presents the results of slurry polymerisation of ethylene that has been initiated by an Al/Ti/Mg-alcohol supported catalyst. Special attention has been paid to the effects of hydrogen, catalyst composition and addition of an α-olefin on catalyst efficiency, molecular weight, crystallinity, and physico-mechanical properties of the final polyolefin. The efficiency of this Al/Ti/Mg catalyst, molecular weight and melting temperature of the formed High Density Polyethylene (HDPE) has been found to decrease as the partial pressure of hydrogen is increased. In parallel, crystallinity and elongation at break of HDPE increase. The composition of this Al/Ti/Mg catalyst has a marked effect on catalyst efficiency, e.g. decrease in the Ti relative content results in an improved efficiency from 86 to 7942 kg PE g-l Ti h-1 as the Mg/Ti molar ratio is increased from 1 to 333. Copolymerisation with 1-octene has also been investigated. When ethylene polymerisation is carried out with this Al/Ti/Mg catalyst at a Mg/Ti ratio of 333, addition of the cr-olefin is responsible for a decrease in the polymerisation rate, which is typical of a negative 'comonomer' effect. This effect is still more pronounced in the presence of H2. Comparison with other catalytic systems has been made in order to understand the role played by the cr-olefin and/or hydrogen on the catalyst efficiency and the physico-mechanical properties of the resulting polyolefins. [less ▲]

Detailed reference viewed: 63 (1 ULg)
Full Text
Peer Reviewed
See detailEthylene polymerization mediated by nickel(II) covalently anchored to silica xerogels
Lambert, Stéphanie ULg; Sacco, Luigi

Conference (2015, September 08)

Heterogeneous catalysis is generally widely preferred for industrial applications thanks to the well-known advantages of easier product-catalyst separation and recovery of the catalyst process and, often ... [more ▼]

Heterogeneous catalysis is generally widely preferred for industrial applications thanks to the well-known advantages of easier product-catalyst separation and recovery of the catalyst process and, often, to the enhanced stability of the catalyst. But in terms of selectivity, homogeneous catalysis usually provides better results. From this point of view, the grafting of homogeneous catalysts onto a solid support seems the ideal combination in order to achieve the advantages of both heterogeneous and homogeneous catalysis, allowing the developing of more environmentally friendly and economical processes with potential application in the industry. Further, to covalently link a homogeneous onto silica (a support which is thermally, chemically and mechanically resistant, with a well defined structure) is the best way to limit metal leaching and sintering. Nitrogen-based ligands containing one of several Schiff bases have been reported to form active catalysts with “late-metal” (such as Fe, Pd, Ni,…) for the ethylene polymerization [1]. Moreover, substituted pyrazole-based organometallic complexes gave also promising results in this field. These facts let us suggest that the pyrazolylpyridine derivatives bearing a tethered trimethoxysilylated group synthesized in a previous work [2] are potentially good candidate to prepare hybrid catalyst (i.e. soluble organometallic complexes covalently bonded onto an insoluble support, in this case silica) with Ni-II, Fe-II or Pd-II for ethylene polymerization. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Peer Reviewed
See detailEthylene production and polyamine content of fully habituated sugarbeet calli
Hagege, D.; Kevers, Claire ULg; Geuns, J. et al

in Journal of Plant Physiology (1994), 143(6), 722-725

[No abstract available]

Detailed reference viewed: 12 (0 ULg)
Full Text
Peer Reviewed
See detailL'éthylisme zutique
Saint-Amand, Denis ULg

in Lefrère, Jean-Jacques; Pierssens, Michel (Eds.) Alcools, actes du XVIe colloque des Invalides (2013)

Detailed reference viewed: 13 (2 ULg)
Full Text
See detailL'éthylisme zutique. Une logique de l'à-fond
Saint-Amand, Denis ULg

Conference (2012, November 16)

Detailed reference viewed: 27 (1 ULg)
Full Text
See detailLa etica de la investigacion en ciencias sociales
Jacquemain, Marc ULg

Scientific conference (2010, February)

La presentacion se centra sobre los problemas de confidencialidad y de respeto de los sujetos de investigaciones sociales. Como tratar de obtener las informaciones necesarias respstando todos los derechos ... [more ▼]

La presentacion se centra sobre los problemas de confidencialidad y de respeto de los sujetos de investigaciones sociales. Como tratar de obtener las informaciones necesarias respstando todos los derechos des las poblaciones que son investigadas. [less ▲]

Detailed reference viewed: 130 (1 ULg)
See detailÉtienne Évrard, Stephania selecta
Denooz, Joseph ULg; Purnelle, Gérald ULg

Book published by CIPL-LASLA (2002)

Detailed reference viewed: 48 (9 ULg)
Full Text
Peer Reviewed
See detailÉtienne Klein, "Le Small Bang des nanotechnologies"
Thoreau, François ULg

in Esprit (Paris, France : 1932) (2012), 381

Detailed reference viewed: 73 (0 ULg)
Full Text
Peer Reviewed
See detailEtiologie de la myopathie atypique : conditions de toxicité de l’agent causal – étude préliminaire
Patarin; van Galen, Gaby; Dopagne, Claude ULg et al

in 40ème journée de la recherche équine (2014, March 18)

Recently it has been shown that atypical myopathy in Europe results from hypoglycin A ingestion, a toxin produced in the seeds (samares) of some trees of the genus Acer. Grasslands of 12 cases of atypical ... [more ▼]

Recently it has been shown that atypical myopathy in Europe results from hypoglycin A ingestion, a toxin produced in the seeds (samares) of some trees of the genus Acer. Grasslands of 12 cases of atypical myopathy for whom the toxic metabolite of hypoglycin A was found in the blood were visited by two experienced botanists in order to establish the list of the different species of trees found in or around these pastures. For all visited pastures, horses had the opportunity to ingest samaras from various maple species. The sycamore maple (Acer pseudoplatanus) was the only common tree in all pastures visited (n = 12 /12). Other trees with samaras were also found near or around the pastures. Since June 2013, a study is conducted to define the conditions of toxicity of several species of trees via the sampling, at regular intervals, of samaras and leaves. The study of the seasonal evolution of the toxicity of these trees in relation to weather conditions and specific biotopes will aim [less ▲]

Detailed reference viewed: 256 (43 ULg)
Peer Reviewed
See detailEtiologie et physiopathologie du diabète de type 2.
SCHEEN, André ULg; PAQUOT, Nicolas ULg; Lefevre, P.

in Problèmes Actuels d'Endocrinologie et de Nutrition (1995), 10

Detailed reference viewed: 81 (0 ULg)
Peer Reviewed
See detailUne étiologie immunologique à l'hyperprolactinemie: la macroprolactinémie
Lebrun, Yves ULg; Luyckx, Françoise ULg; Brue, T. et al

in Revue Médicale de Liège (1999), 54(9), 759-63

Besides classical etiologies of hyperprolactinaemia (pregnancy, pharmacological treatments, pituitary or hypothalamic perturbations), another less known cause may explain a spectacular idiopathic ... [more ▼]

Besides classical etiologies of hyperprolactinaemia (pregnancy, pharmacological treatments, pituitary or hypothalamic perturbations), another less known cause may explain a spectacular idiopathic elevation of plasma concentrations of prolactin hormone. Macroprolactinaemia is characterized by the presence of a circulating high molecular weight complex of prolactin with an immunoglobulin G. In this article, we report the cases of 3 female patients for whom size exclusion chromatography technique permitted to give a precise biological diagnosis and to avoid heavy, expensive, time consuming and unnecessary clinical investigations or therapeutic actions. Patients with macroprolactinaemia do not exhibit clinical features of classical hyperprolactinaemia, notably as regard to menstrual and fertility disturbances. [less ▲]

Detailed reference viewed: 159 (0 ULg)
See detailL'étiologie, la génétique de l'acromégalie
Beckers, Albert ULg

Scientific conference (2015, October)

Detailed reference viewed: 23 (1 ULg)
Full Text
Peer Reviewed
See detailEtiologies et exploration electrophysiologique des paralysies diaphragmatiques.
MAERTENS DE NOORDHOUT, Alain ULg

in Revue Neurologique (2004), 160(12), 1239-44

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailEtiology in Parthenius of Nicaea
Vandersmissen, Marc ULg

in Euphrosyne (2014), 42

Detailed reference viewed: 27 (1 ULg)
Full Text
See detailÉtiopathogénie de la myopathie atypique et gestion raisonnée des cas
Votion, Dominique ULg; Patarin, Florence; Cerri, Simona ULg et al

in In Proceedings: Journée AVEF (Association des Vétérinaires Equins Français) (2013, December)

Atypical myopathy is an acute intoxication resulting from the ingestion of a toxin contained in the seeds of some trees of the genus Acer (i.e. « maple trees »). The causes of the emergence of the disease ... [more ▼]

Atypical myopathy is an acute intoxication resulting from the ingestion of a toxin contained in the seeds of some trees of the genus Acer (i.e. « maple trees »). The causes of the emergence of the disease due to trees naturalized for many decades remain undetermined. Currently, there is no cure for atypical myopathy but symptomatic treatment may be revisited on the basis of knowledge of the aetio-pathogenesis of the disease. This paper compiles recommendations following a discussion on treatment of atypical myopathy held in October 2013 at the University of Liege (Belgium) to provide emergency treatment distinguishing clinical management (1) at hospital, (2) in the field and (3) preventive measures to protect pasture companions. [less ▲]

Detailed reference viewed: 121 (31 ULg)
Full Text
Peer Reviewed
See detailEtiopathogenie et physiopathologie du diabete de type 2
Fery, Françoise; Paquot, Nicolas ULg

in Revue Médicale de Liège (2005), 60(5-6), 361-8

Etiopathogenesis of type 2 diabetes is complex and still partially unknown. Its etiology is determined by the interaction of genetic and environmental factors. The genetic contribution is important, but ... [more ▼]

Etiopathogenesis of type 2 diabetes is complex and still partially unknown. Its etiology is determined by the interaction of genetic and environmental factors. The genetic contribution is important, but has a polygenic origin. Obesity, especially when fat mass is preferably located in the abdomen, is the main predisposing factor for type 2 diabetes, and almost 80% of diabetic patients are overweight or obese. The diabetogenic effect of obesity is due to the capacity of excessive fat mass to induce or aggravate insulin resistance. Increasing lack of physical activity is also a contributing factor as it increases insulin resistance. As far as pathophysiology is concerned, the development of type 2 diabetes results from the coexistence of abnormalities of insulin secretion and insulin action. Insulin secretory dysfunction, whose underlying mechanism remains poorly understood, is characterized by a relative defect in circulating insulin levels of variable severity. Resistance to insulin action is located in the liver (increased hepatic glucose production), in the skeletal muscle (decreased muscular glucose uptake) and in the adipose tissue (exaggerated lipolysis with elevated plasma free fatty acids). Changes in life-style habits (weight reduction, regular physical activity) are able to prevent or delay the development of type 2 diabetes. [less ▲]

Detailed reference viewed: 1301 (10 ULg)
Full Text
Peer Reviewed
See detailEtioplast differentiation in Arabidopsis: Both PORA and PORB restore the prolamellar body and photoactive protochlorophyllide-F655 to the cop1 photomorphogenic mutant
Sperling, U.; Franck, Fabrice ULg; van Cleve, B. et al

in Plant Cell (1998), 10(2), 283-296

The etioplast plastid type of dark-grown angiosperms is defined by the accumulation of the chlorophyll (Chi) precursor protochlorophyllide (Pchlide) and the presence of the paracrystalline prolamellar ... [more ▼]

The etioplast plastid type of dark-grown angiosperms is defined by the accumulation of the chlorophyll (Chi) precursor protochlorophyllide (Pchlide) and the presence of the paracrystalline prolamellar body (PLB) membrane. Both features correlate with the presence of NADFH:Pchlide oxidoreductase (FOR), a light-dependent enzyme that reduces photoactive Pchlide-F655 to chlorophyllide and plays a key role in chloroplast differentiation during greening. Two differentially expressed and regulated FOR enzymes, FORA and FORB, have recently been discovered in angiosperms. To investigate the hypothesis that etioplast differentiation requires FORA, we have constitutively overexpressed PORA and FORB in the Arabidopsis wild type and in the constitutive photomorphogenic cop1-18 (previously det340) mutant, which is deficient in the PLB and Pchlide-F655. In both genetic backgrounds, FOR overexpression increased PLB size, the ratio of Pchlide-F655 to nonphotoactive Pchl[ide]-F632, and the amount of Pchlide-F655. Dramatically, restoration of either FORA or FORB to the cop1 mutant led to the formation of etioplasts containing an extensive PLB and large amounts of photoactive Pchlide-F655. [less ▲]

Detailed reference viewed: 27 (0 ULg)
See detailL'étiquetage des denrées alimentaires
De Laubier, Juliette ULg; Godrie, Thérèse ULg; Sindic, Marianne ULg

Conference given outside the academic context (2013)

Detailed reference viewed: 23 (6 ULg)