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91.
Wonihl?ChoEmail author Seung-Ho?Lee Youngsoon?Baek Seong-Min?Lee Young?Tai?Kho 《Korean Journal of Chemical Engineering》2003,20(2):230-234
Catalytic combustion for applying heat shrink sleeves (HSS) to a pipeline in KOGAS was investigated. We used a low temperature
catalytic combustor in order to place HSS in the conduit. The surface temperature of the catalytic combustor maintained the
conditions at which HSS can become well-adhesive at the conduit. Therefore, the automatic HSS construction provided the chance
to establish gas pipeline safety by an automatic catalytic combustor device. 相似文献
92.
Liquid-phase catalytic degradation of waste polyolefinic polymers (HDPE, LDPE, PP) over spent fluid catalytic cracking (FCC)
catalyst was carried out at atmospheric pressure with a stirred semi-batch operation. The effect of experimental variables,
such as catalyst amount, reaction temperature, plastic types and weight ratio of mixed plastic on the yield and accumulative
amount distribution of liquid product for catalytic degradation was investigated. The initial rate of catalytic degradation
of waste HDPE was linearly increased with catalyst amount (4-12 wt%), while that was exponentially increased with reaction
temperature (350-430 ‡C). Spent FCC catalyst in the liquid-phase catalytic degradation of polymer was not deactivated fast.
The product distribution from catalytic degradation using spent FCC catalyst strongly depended on the plastic type. The catalytic
degradation of mixed plastic (HDPE: LDPE: PP: PS=3: 2: 3: 1) showed lower degradation temperature by about 20 ‡C than that
of pure HDPE. 相似文献
93.
The diastereoselective hydrogenation catalyzed by heterogeneous metallic catalysts uses a covalently bound chiral auxiliary to induce the chirality. It remains an active synthetic methodology in the asymmetric synthesis of chiral products and may proceed with high diastereoselectivity. This review describes recent examples using this method, such as hydrogenation of C=C, C=O, and C=N bonds. The use of a chiral auxiliary group has also been successfully applied to the hydrogenation of aromatic and heteroaromatic rings. The choice of the chiral auxiliary was found to play a key role in the asymmetric hydrogenation. The results could be explained in terms of steric effect, with a preferred conformation of the adduct substrate and the addition occurring from the less bulky side. The catalytic metal, the support and the presence of additives were also found to have a significant influence. 相似文献
94.
Top S Kaloun el B Vessières A Leclercq G Laïos I Ourevitch M Deuschel C McGlinchey MJ Jaouen G 《Chembiochem : a European journal of chemical biology》2003,4(8):754-761
The goal of our study was to potentiate the effects of the ((R,R)-trans-1,2-diaminocyclohexane)-platinum(II) fragment [(DACH)Pt], known for its cytotoxic properties, either with tamoxifen (Tam), the most widely used antiestrogen in the treatment of hormone-dependent breast cancers, or with its active metabolite hydroxytamoxifen (hydroxy-Tam). We coupled Tam or hydroxy-Tam derivatives bearing a malonato group at the para position of the beta aromatic ring with the (DACH)Pt fragment. The malonato-Tam and malonato-hydroxy-Tam compounds were prepared through McMurry coupling of the appropriate ketones. The presence of the malonate group resulted in a pronounced stereospecificity in the reaction, since malonato-Tam was obtained only as the Z isomer, while malonato-hydroxy-Tam was obtained as an 80/20 E/Z mixture. Attribution of the isomeric structures was achieved by 2D NMR spectroscopy. The platinum complexes (DACH)Pt-malonato-Tam and (DACH)Pt-malonato-hydroxy-Tam were then prepared by coupling the barium salts derived from the malonato-Tam and malonato-hydroxy-Tam with the nitrate derived from (DACH)PtCl(2). Study of the biochemical properties of these two platinum complexes showed that, while the hydroxy-Tam complex is satisfactorily recognized by the estrogen receptor (relative binding affinity, RBA=6.4 %), the Tam complex is less well recognized (RBA=0.5 %). The effects of these complexes on two hormone-dependent breast cancer cell lines (MCF7 and MVLN) were studied in vitro. Both complexes showed an antiproliferative effect on MCF7 cells, and an antiestrogenic effect on MVLN cells. The observed effects appear to be essentially antihormonal, since incorporation of the (DACH)Pt fragment into the tamoxifen skeleton did not cause an increase in the cytotoxicity of the complexes. 相似文献
95.
Dr. Mohamed Ettaoussi Dr. Ahmed Sabaouni Dr. Basile Pérès Elodie Landagaray Dr. Olivier Nosjean Dr. Jean A. Boutin Dr. Daniel‐Henri Caignard Dr. Philippe Delagrange Prof. Pascal Berthelot Dr. Saïd Yous 《ChemMedChem》2013,8(11):1830-1845
Agomelatine is a naphthalenic analogue of melatonin that is in clinical use for the treatment of major depressive disorders. Interestingly, while agomelatine exhibits potent affinity for melatonin receptors, it binds with only moderate affinity to the serotonin 5‐HT2C receptor. Optimization of agomelatine toward this target could further potentiate its clinical efficacy. To explore this hypothesis and to access derivatives in which a key point of agomelatine metabolism is blocked, a series of naphthalenic derivatives was designed and synthesized as novel analogues of agomelatine. Most of the prepared compounds exhibited good binding affinity at the melatonin MT1 and MT2 receptor subtypes. Two compounds, an acetamide and an acrylamide derivative, exhibited good binding affinities at both the human melatonin (MT) receptors and the serotonin 5‐HT2C receptor subtype, with pKi values of 7.96 and 7.95 against MT1, 7.86 and 8.68 against MT2, and 6.64 and 6.44 against 5‐HT2C, respectively. 相似文献
96.
Van Son Nguyen Laurent Badie Emmanuel Lamouroux Brice Vincent Fabrice Domingues Dos Santos Maëlen Aufray Yves Fort Didier Rouxel 《应用聚合物科学杂志》2013,129(1):391-396
Piezoelectric films were prepared by incorporation of lithium niobate (LiNbO3) nanoparticles into copolymer of vinylidene difluoride and trifluoroethylene. Nanoparticles of LiNbO3 with ferroelectric phase were successfully synthesized and dispersed homogenously by ultrasonication in the copolymer matrix without any surfactant or surface functionalization. The nanocomposites were fully characterized by electronic microscopy, X‐ray diffraction, differential scanning calorimetry, dynamical mechanical analysis, and piezometer. Surprisingly, the copolymer matrix crystallinity and morphology were not affected by the incorporation of nanoparticles. Therefore the nanocomposites remained good mechanicals properties and high ferroelectricity coupled to nonlinear optical activity thanks to the noncentro symmetric space group of lithium niobate. This could be a novel approach to develop new multifunctional materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
97.
Multilayer films ageing under ultraviolet radiations: Complementary study by dielectric spectroscopy
Simon Lewandowski Virginie Rejsek‐Riba Alain Bernès Sophie Perraud Colette Lacabanne 《应用聚合物科学杂志》2013,129(6):3772-3781
The effect of ultraviolet (UV) irradiation on a multilayer film made of poly(ethylene terephthalate)/Polyamide 6/poly(ethylene terephthalate) was investigated by uniaxial tractions, UV‐visible‐NIR and Fourier transformed infra‐red‐attenuated total reflection spectroscopy, differential scanning calorimetry ( DSC), and dynamic dielectric spectroscopy (DDS). The multilayer was exposed to ultraviolet radiations (filtered at 270 nm) for 7 days, in air. The complexity of the multilayer thermograms recorded by DSC and DDS has required the study of each film constituting the multilayer to assess each the contribution of each one of them. A deterioration in mechanical properties and a decrease in UV transmission for low wavelengths are observed. These evolutions seem to result to the photo‐oxidation of the poly(ethylene terephthalate) film mainly localized at the exposed layer. This layer acts as a UV protection filter for the other layers. However, the DDS analyses show a plasticization effect of the primary mode in the Polyamide 6, which is evidence of photo‐oxidation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
98.
Sebastien Narses Faten Sadaka Claire‐Hélène Brachais Jean‐Pierre Couvercelle 《应用聚合物科学杂志》2013,129(5):2891-2904
The coloration of different polymer films (from commodity and packaging films to performance films) by contact with various food coloring substances was evaluated. For this purpose, both solubility parameters as a prediction tool, and immersion experiments for time range between 24 and 1000 h were established. The two predicting tools are the Hoy and Hoftyzer‐Van Krevelen (HVK) methods. For PE and PP, HVK's method is preferred for predicting coloration. Neither of the HVK's and Hoy's methods was able to establish a coloration prediction for PET while both methods could predict the staining of PEEK. The coloration of partially and fully fluorinated polymers is well predicted by the Hoy's method. The behavior of PP/PA and PP/PA/PP multilayer films was also studied. Crystallinity degree of polymers, temperature and concentration of coloring molecules are also important parameters, which are not taken into account in solubility theories. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
99.
Abbas Hodroj Patrick Simon Pierre Florian Marie‐Hélène Chopinet Yann Vaills 《Journal of the American Ceramic Society》2013,96(8):2454-2460
The morphological and structural properties of sodium silicate (Na2O–SiO2) glasses were analyzed using atomic force microscopy (AFM) and light scattering following thermal treatments. AFM observations indicated that the glass surface microstructure evolves during the phase separation mechanisms from continuous interpenetrating phases in the spinodal decomposition process to separated droplets embedded in a continuous matrix for the nucleation/growth one. Raman mapping gave evidence of a phase separation through the nucleation/growth process with formation of silica‐rich clusters characterized by higher polymerization degree as separate droplets. The variations in inhomogeneities versus temperature investigated by Brillouin are exponential for spinodal decomposition and linear in the case of nucleation/growth mechanism. Nuclear magnetic resonance spectroscopy was used to investigate the spatial distribution of the various Qn species present in thermally treated glasses and allows determining fractal dimension between two and three. 相似文献
100.
The image and van der Waals contributions to the metal/oxide work of adhesion are compared through the extent to which they follow the known prevalent trends, i.e. the increase in work of adhesion (a) with narrowing oxide band gap and (b) with increasing conduction electron density of the metal. The van der Waals interaction is shown to follow both trends, while the image term is suggested to be significant only for dense metals in contact with very ionic oxides. The relative contribution of these long-range interactions to the overall metal/oxide work of adhesion is found to be maximized for systems involving metals with low electronic densities and oxides with wide band gaps. At variance, high metallic electronic densities and narrow oxide gaps likely favour short-range interactions arising from charge transfer. 相似文献