Analyse organique fonctionnelle : Combinaisons du dimédon (diméthyl-5,5 cyclohexa-nedione-1,3) avec les aldéhydes

The authors have traced and studied the thermolysis curves of dimedone and of the compounds it forms with 26 very different aldehydes. The purity of the aldehydes have been rigorously checked by infrared spectrography.     

Sur la stabilité thermique des étalons analytiques. VI

Twelve substances, which can be used as standards in volumetric analysis were studied, special attontion being paid to the pyrolysis of the three iron salts among these substances.     

Finsler Spinoptics

The objective of this article is to build up a general theory of geometrical optics for spinning light rays in an inhomogeneous and anisotropic medium modeled on a Finsler manifold. The prerequisites of local Finsler geometry are reviewed together with the main properties of the Cartan connection used in this work. Then, the principles of Finslerian spinoptics are formulated on the grounds of previous work on Riemannian spinoptics, and relying on the generic coadjoint orbits of the Euclidean group. A new presymplectic structure on the indicatrix-bundle is introduced, which gives rise to a foliation that significantly departs from that generated by the geodesic spray, and leads to a specific anomalous velocity, due to the coupling of spin and the Cartan curvature, and related to the optical Hall effect. UMR 6207 du CNRS associée aux Universités d’Aix-Marseille I et II et Université du Sud Toulon-Var; Laboratoire affilié à la FRUMAM-FR2291.     

Sur la thermogravimétrie des précipités analytiques : Dosage du bismuth

With the help of the CHEVENARD thermobalance, the authors have traced the 36 pyrolysis curves of the precipitates used for the gravimetric determination of bismuth. They have retained 15 methods suitable for the automatic determination. In particular, they recommend the methods using thionalide, phenyldithiobiazolonethiol, and phenylaisonic acid. A critical examination of the methods selected for the gravimetric determination of bismuth seems to show that MAJUMDAR's phenyldithiobiazolonethiol is the best available at present. The authors suggest the rejection (because constant weight is not reached, or because quantitative precipitation does not occur, or because the formula of the compounds formed does not tally with the one presumed) of the precipitation methods using glucose, hypophosphorous acid, iodic acid, hydrogen sulphide, sodium thiosulphate, potassium bichromate, ammonium molybdate, potassium chromic thiocyanate, hexamethylenetetramine, pyrogallol, gallic acid, oxine, antipyrine-methyleneamine, and α-naphthoquinoline.     

Sur la thermogravimétrie des précipités analytiques : Dosage du zinc

With the help of the CHEVENARD thermobalance, the authors have traced the pyrolysis curves of the precipitates which serve for the gravimetric determination of zinc. In the table, the temperature limits and the forms in which the precipitates are weighed, are listed. Eight new reagents for the automatic determination of zinc are included in the table.     

Sur la thermogravimétrie des précipités analytiques: Dosage du chrome

By means of the CHEVENARD thermobalance, the precipitates used for the determination of chromium have been investigated and the following limits of temperature established:

     

67.

Heparin coating of poly(ethylene terephthalate) decreases hydrophobicity, monocyte/leukocyte interaction and tissue interaction     

van Bilsen PH  Krenning G  Billy D  Duval JL  Huurdeman-Vincent J  van Luyn MJ 《Colloids and surfaces. B, Biointerfaces》2008,67(1):46-53

Woven poly(ethylene terephthalate) (PET) is widely used in implantable medical devices. Upon implantation, fibrinogen interacts with the PET and changes conformation, such that the fibrinogen P2 epitope may become exposed. This allows inflammatory cells to interact with the material. In this study we have coated PET with heparin and show that this decreases PET hydrophobicity and the presence of the fibrinogen P2 epitope on the material surface. In addition, we show that heparin-induced reduction of PET hydrophobicity correlates with decreased exposure of the fibrinogen P2 epitope and reduced adhesion of monocytes. Reduction of PET hydrophobicity was furthermore associated with reduced PMN elastase production and decreased interaction between PET and embryonic chicken tissue. We conclude that the heparin coating-induced decrease in PET hydrophobicity is associated with decreased interaction between PET and inflammatory cells. Independent of this interaction, the hydrophobic nature of the heparin coating is related to tissue interaction as demonstrated by a reduction in adhesion, growth and spreading of tissue on PET. The combination of these properties makes heparin coating a candidate for improving biocompatibility of PET.     

68.

Lanthanum(III) and uranyl(VI) diglycolamide complexes: synthetic precursors and structural studies involving nitrate complexation     

Kannan S  Moody MA  Barnes CL  Duval PB 《Inorganic chemistry》2008,47(11):4691-4695

The synthesis and structural characterization of lanthanum(III) and uranyl(VI) complexes coordinated by tridentate diglycolamide (DGA) ligands O(CH2C(O)NR2)2[R=i-Pr (L1), i-Bu (L2)] are described. Reaction of L with UO2Cl2(H2O) n forms the uranyl(VI) cis-dichloride adducts UO2Cl2L [L=L1 (1a), L2 (1b)], while reaction of excess L with the corresponding metal nitrate hydrate produces [LaL3][La(NO3)6] [L=L1 (2a), L2 (2b)] for lanthanum and UO2(NO3)2L [L=L1 (3a), L2 (3b)] for uranium. Compounds 2b and 3a have been structurally characterized. The solid-state structure of the cation of 2b shows a triple-stranded helical arrangement of three tridentate DGA ligands with approximate D3 point-group symmetry, while the counteranion consists of six bidentate nitrate ligands coordinated around a second La center. The solid-state structure of 3a shows a tridentate DGA ligand coordinated along the equatorial plane perpendicular to the OUO unit as well as two nitrate ligands, one bidentate and oriented in the equatorial plane and the other monodentate and oriented parallel to the uranyl unit with the oxygen donor atom situated above the mean equatorial plane. Ambient-temperature NMR spectra for 3a and 3b indicated an averaged chemical environment of high symmetry consistent with fluxional nitrate hapticity, while spectroscopic data obtained at -30 degrees C revealed lower symmetry consistent with the slow-exchange limit for this process.     

69.

Effect of the kinematic hardening on the plastic anisotropy parameters for metallic sheets     

Houssem Badreddine  Khemais Saanouni  Carl Labergère  Jean-Louis Duval 《Comptes Rendus Mecanique》2018,346(8):678-700

The initial plastic anisotropy parameters are conventionally determined from the Lankford strain ratios defined by $r^{\psi }=\frac{{\epsilon }_{22}^{\mathrm{p}\psi }}{{\epsilon }_{33}^{\mathrm{p}\psi }}$ (ψ being the direction of the loading path). They are usually considered as constant parameters that are determined at a given value of the plastic strain far from the early stage of the plastic flow (i.e. equivalent plastic strain of ${\epsilon }_{\mathrm{eq}}^{\mathrm{p}}=0.2\text{\%}$) and typically at an equivalent plastic strain in between 20% and 50% of plastic strain failure (or material ductility). What prompts to question about the relevance of this determination, considering that this ratio does not remain constant, but changes with plastic strain. Accordingly, when the nonlinear evolution of the kinematic hardening is accounted for, the Lankford strain ratios are expected to evolve significantly during the plastic flow.In this work, a parametric study is performed to investigate the effect of the nonlinear kinematic hardening evolution of the Lankford strain ratios for different values of the kinematic hardening parameters. For the sake of clarity, this nonlinear kinematic hardening is formulated together with nonlinear isotropic hardening in the framework of anisotropic Hill-type (1948) yield criterion. Extension to other quadratic or non-quadratic yield criteria can be made without any difficulty. This parametric study is completed by studying the effect of these parameters on simulations of sheet metal forming by large plastic strains.     

70.

Geant4 Monte Carlo simulations for the LPCTrap setup     

D. Rodríguez  G. Ban  D. Durand  F. Duval  X. Fléchard  E. Liénard  F. Mauger  A. Méry  O. Naviliat-Cuncic  J. -C. Thomas  Ph. Velten 《The European Physical Journal A - Hadrons and Nuclei》2009,42(3):397-400

The LPCTrap setup at GANIL is fully operational since 2006. The first breakthrough was the detection of 100000 coincidences between the $ \beta$ particles and the recoil ions from the decay of ⁶He⁺ produced by the SPIRAL source. After preparation, the decaying nuclei are confined in a transparent Paul trap which is surrounded by a $ \beta$ -telescope made of a double-sided silicon strip detector followed by a scintillator, and by a micro-channel plate position-sensitive detector to record in coincidence the $ \beta$ particles and the recoil ions. Simulations of this system are needed in order to study possible systematic effects and extract with high accuracy the $ \beta$ - $ \nu$ angular-correlation coefficient. A code based on Geant4 is well suited for this purpose. In this contribution the results from the simulations compared with those from the experiment will be presented and discussed.     

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Precipitating reagent	Form in which weighed	Temperature limits
Ammonium hydroxide (to a chromic salt)	Cr2O3	> 812°
Ammonium hydroxide (to chromic acid)	Cr2O3	> 188°
Ammoniac (gas)	Cr(OH)3	440–475°
Ammoniac (gas)	Cr2O3	> 845°
Aniline	Cr2O3	> 830°
Hydroxylamine	Cr2O3	> 850°
Thiosemicarbazide	Cr2Oa3.H2O	380–410°
Thiosemicarbazide	Cr2O3	> 475°
Potassium cyanate	Cr2O3.H2O	320–370°
Potassium cyanate	Cr2O3	> 473°
Ammonium nitrite	Cr2O3	> 880°
Potassium iodo-iodate	Cr2O3	> 850°
Disodium phosphate	CrPO4	> 946°
Silver nitrate	Ag2CrO4	92–812°
Mercurous nitrate	Hg2CrO4	82–256°
Mercurous nitrate	Cr2O3	> 671°
Barium nitrate	BaCrO4	< 60°
Lead nitrate	PbCrO4	91–904°
8-Hydroxyquinoline	Cr(C9H6ON)3	70–156°
8-Hydroxyquinoline	Cr2O3	> 500°

Heparin coating of poly(ethylene terephthalate) decreases hydrophobicity, monocyte/leukocyte interaction and tissue interaction

Woven poly(ethylene terephthalate) (PET) is widely used in implantable medical devices. Upon implantation, fibrinogen interacts with the PET and changes conformation, such that the fibrinogen P2 epitope may become exposed. This allows inflammatory cells to interact with the material. In this study we have coated PET with heparin and show that this decreases PET hydrophobicity and the presence of the fibrinogen P2 epitope on the material surface. In addition, we show that heparin-induced reduction of PET hydrophobicity correlates with decreased exposure of the fibrinogen P2 epitope and reduced adhesion of monocytes. Reduction of PET hydrophobicity was furthermore associated with reduced PMN elastase production and decreased interaction between PET and embryonic chicken tissue. We conclude that the heparin coating-induced decrease in PET hydrophobicity is associated with decreased interaction between PET and inflammatory cells. Independent of this interaction, the hydrophobic nature of the heparin coating is related to tissue interaction as demonstrated by a reduction in adhesion, growth and spreading of tissue on PET. The combination of these properties makes heparin coating a candidate for improving biocompatibility of PET.     

Lanthanum(III) and uranyl(VI) diglycolamide complexes: synthetic precursors and structural studies involving nitrate complexation

The synthesis and structural characterization of lanthanum(III) and uranyl(VI) complexes coordinated by tridentate diglycolamide (DGA) ligands O(CH2C(O)NR2)2[R=i-Pr (L1), i-Bu (L2)] are described. Reaction of L with UO2Cl2(H2O) n forms the uranyl(VI) cis-dichloride adducts UO2Cl2L [L=L1 (1a), L2 (1b)], while reaction of excess L with the corresponding metal nitrate hydrate produces [LaL3][La(NO3)6] [L=L1 (2a), L2 (2b)] for lanthanum and UO2(NO3)2L [L=L1 (3a), L2 (3b)] for uranium. Compounds 2b and 3a have been structurally characterized. The solid-state structure of the cation of 2b shows a triple-stranded helical arrangement of three tridentate DGA ligands with approximate D3 point-group symmetry, while the counteranion consists of six bidentate nitrate ligands coordinated around a second La center. The solid-state structure of 3a shows a tridentate DGA ligand coordinated along the equatorial plane perpendicular to the OUO unit as well as two nitrate ligands, one bidentate and oriented in the equatorial plane and the other monodentate and oriented parallel to the uranyl unit with the oxygen donor atom situated above the mean equatorial plane. Ambient-temperature NMR spectra for 3a and 3b indicated an averaged chemical environment of high symmetry consistent with fluxional nitrate hapticity, while spectroscopic data obtained at -30 degrees C revealed lower symmetry consistent with the slow-exchange limit for this process.     

Effect of the kinematic hardening on the plastic anisotropy parameters for metallic sheets

The initial plastic anisotropy parameters are conventionally determined from the Lankford strain ratios defined by $r^{\psi }=\frac{{\epsilon }_{22}^{\mathrm{p}\psi }}{{\epsilon }_{33}^{\mathrm{p}\psi }}$ (ψ being the direction of the loading path). They are usually considered as constant parameters that are determined at a given value of the plastic strain far from the early stage of the plastic flow (i.e. equivalent plastic strain of ${\epsilon }_{\mathrm{eq}}^{\mathrm{p}}=0.2\text{\%}$) and typically at an equivalent plastic strain in between 20% and 50% of plastic strain failure (or material ductility). What prompts to question about the relevance of this determination, considering that this ratio does not remain constant, but changes with plastic strain. Accordingly, when the nonlinear evolution of the kinematic hardening is accounted for, the Lankford strain ratios are expected to evolve significantly during the plastic flow.In this work, a parametric study is performed to investigate the effect of the nonlinear kinematic hardening evolution of the Lankford strain ratios for different values of the kinematic hardening parameters. For the sake of clarity, this nonlinear kinematic hardening is formulated together with nonlinear isotropic hardening in the framework of anisotropic Hill-type (1948) yield criterion. Extension to other quadratic or non-quadratic yield criteria can be made without any difficulty. This parametric study is completed by studying the effect of these parameters on simulations of sheet metal forming by large plastic strains.     

Geant4 Monte Carlo simulations for the LPCTrap setup

The LPCTrap setup at GANIL is fully operational since 2006. The first breakthrough was the detection of 100000 coincidences between the $ \beta$ particles and the recoil ions from the decay of ⁶He⁺ produced by the SPIRAL source. After preparation, the decaying nuclei are confined in a transparent Paul trap which is surrounded by a $ \beta$ -telescope made of a double-sided silicon strip detector followed by a scintillator, and by a micro-channel plate position-sensitive detector to record in coincidence the $ \beta$ particles and the recoil ions. Simulations of this system are needed in order to study possible systematic effects and extract with high accuracy the $ \beta$ - $ \nu$ angular-correlation coefficient. A code based on Geant4 is well suited for this purpose. In this contribution the results from the simulations compared with those from the experiment will be presented and discussed.