Search results for "liquid"

Copolymerization of ethylene with norbornene or 1-octene using supported ionic liquid systems

2016

Copolymerization of ethylene with norbornene (E/NB) and ethylene with 1-octene (E/Oct) is performed using supported ionic liquid (SIL) systems, in which metallocene (Cp2VCl2) or post-metallocene [VCl2(salenCl2)] vanadium catalysts are immobilized in pyridinium chloroaluminate ionic liquid supported on silica. The studied SIL catalysts show higher activities as well as stability than their non-supported analogues. In addition, higher activities and better comonomer incorporation are observed for norbornene (above 30 mol%). The comonomer incorporation has considerable influence on copolymer molecular weight (M w), melting temperature, crystallinity degree, and microstructure of the copolymers…

Titanium and vanadium catalysts with oxazoline ligands for ethylene-norbornene (co)polymerization

2018

A series of catalysts, (Py-ox)TiCl4, (Py-box)TiCl4, (Py-ox)VCl3, (Py-box)VCl3, SIL/(Py-ox)VCl3, SIL/(Py-box)VCl3, with 2-(1,3-oxazolin-2-yl)pyridine (Py-ox) and 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box) ligands, silica support modified by 1-[3-(triethoxysilyl)propyl]pyridinium ethylchloroaluminate ionic liquid (SIL), activated by AlEt2Cl, AlEtCl2, and methylaluminoxane (MMAO) were studied in ethylene polymerization and ethylene-norbornene copolymerization. Single-crystal X-ray diffraction is given for both Py-ox and Py-box. The complexation was confirmed by NMR and ESI-MS methods. All complexes were found to be active in ethylene polymerization with better performance of the vanadium cata…

Studio dell’interazione Im-Eu-X: nuovi leganti ecocompatibili per l’Europio

Fluorescent interaction Eu-IL: when the anion plays a role

2020

Determination of N-acetyl-l-glutamine in urine by HPLC

1986

The determination of N-acetyl-l-glutamine (AC-GLN) in urine of rats after derivatization with xanthydrol by HPLC is described. The urine samples were collected from two groups of rats, one group fed normal nutrition, the other treated with AC-GLN. About 5 mM/l AC-GLN was detected in urine of untreated animals, whereas the excretion of the other group was in the range of 50 mM/l corresponding to about 50 wt.-% of the given AC-GLN.

The long memory of efficient market

2004

For the London Stock Exchange we demonstrate that the signs of orders obey a long-memory process. The autocorrelation function decays roughly as a power law with an exponent of 0.6, corresponding to a Hurst exponent H = 0.7. This implies that the signs of future orders are quite predictable from the signs of past orders; all else being equal, this would suggest a very strong market inefficiency. We demonstrate, however, that fluctuations in order signs are compensated for by anti-correlated fluctuations in transaction size and liquidity, which are also long-memory processes that act to make the returns whiter. We show that some institutions display long-range memory and others don't.

Combustion synthesis of MoSi2 and MoSi2–Mo5Si3 composites: Multilayer modeling and control of the microstructure

2010

International audience; In this work, we present a multilayer modeling for the formation of molybdenum silicides in the exothermic reaction between Mo and Si under the influence of a temperature pulse. The heating rate can either be a well-controlled ramp or be generated spontaneously by the propagation of a combustion synthesis front. The model addresses the specific situation above the melting point of silicon and describes the solid–liquid reaction taking place in a single representative particle of molybdenum surrounded by the melt of silicon. We obtain a set of kinetic equations for the propagation of the interfaces between the different layers (Mo/Mo5Si3 and Mo5Si3/MoSi2) in the solid…

1990

Attenuation of the Fourth Sound in Liquid Helium II via Extended Thermodymamics

2004

Cautionnement. Défaut de déclaration par le créancier dans le délai réglementaire, Déclaration par la seule caution, Extinction de plein droit de la …

1991

International audience