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161.
Paloma Navia Jacobo Troncoso Luis Romaní 《The Journal of chemical thermodynamics》2008,40(11):1607-1611
A new method for determining isobaric thermal expansivity of liquids as a function of temperature and pressure through calorimetric measurements against pressure is described. It is based on a previously reported measurement technique, but due to the different kind of calorimeter and experimental set up, a new calibration procedure was developed. Two isobaric thermal expansivity standards are needed; in this work, with a view on the quality of the available literature data, hexane and water are chosen. The measurements were carried out in the temperature and pressure intervals (278.15 to 348.15) K and (0.5 to 55) MPa for a set of liquids, and experimental values are compared with the available literature data in order to evaluate the precision of the experimental procedure. The analysis of the results reveals that the proposed methodology is highly accurate for isobaric thermal expansivity determination, and it allows obtaining a precise characterisation of the temperature and pressure dependence of this thermodynamic coefficient. 相似文献
162.
163.
At present, there is a considerable amount of work devoted to the study of the thermophysical properties of pure ionic liquids,
which contrasts with the few data available for their mixtures. One of the most appealing characteristics of ionic liquids
is the capability of subtly changing the chemical structure of the cation and anion in order to design appropriate solvents
for specific applications. Mixtures of ionic liquids increase enormously this specificity, due to the unlimited combinations
that arise from mixing two or more ionic liquids. In this context, the study of the thermophysical properties of these mixtures
is revealed as a fundamental task. In this work the viscosities of the ionic liquid binary mixtures with a common ion ([C6mim] + [C2mim])[BF4], ([C6mim] + [C4mim])[BF4], [C4mim]([BF4] + [MeSO4]) and [C4mim]([PF6] + [BF4]) were determined within the temperature range (298.15–308.15) K. The temperature dependence of the viscosity for pure liquids
is analyzed by means of the Vogel-Tammann-Fulcher equation and several mixing rules are applied for the mixtures. 相似文献
164.
Escudero R Gómez-Gallego M Romano S Fernández I Gutiérrez-Alonso Á Sierra MA López-Rayo S Nadal P Lucena JJ 《Organic & biomolecular chemistry》2012,10(11):2272-2281
In this study we have obtained experimental evidence that confirms the high activity of aquo complexes III and IV towards the enzyme FCR, responsible for the reduction of Fe(III) to Fe(II) in the process of iron acquisition by plants. The in vivo FCR assays in roots of stressed cucumber plants have shown a higher efficiency of the family of complexes III and a striking structure-activity relationship with the nature of the substituent placed in a phenyl group far away from the metal center. The results obtained in this work demonstrate that all the aquo compounds tested interact efficiently with the enzyme FCR and hence constitute a new concept of iron chelates that could be of great use in agronomy. 相似文献
165.
Simó C Pérez P Neusüss C Pelzing M San Román J Gallardo A Cifuentes A 《Electrophoresis》2006,27(11):2250-2258
Analytical characterization of dimethacrylate-tyrosine-lysine-tyrosine (DMTLT, a new biodegradable acrylic cross-linker synthesized at our laboratory) is carried out using CE-MS. DMTLT is a pseudopeptide composed by tyrosine-lysine-tyrosine amino acids linked through urea bonds with two methacrylic groups, one at each end of the molecule, making this compound an excellent cross-linker for polymerization reactions and for obtaining new biodegradable materials. A new CE-MS method is developed for the characterization of DMTLT and its products of degradation after basic hydrolysis. In order to carry out an exhaustive examination of such degradation products methods based on CE coupled to IT and TOF-MS are employed. Based on CE-IT-MS results and the elemental composition of the degradation products obtained by CE-TOF-MS, conclusions on the mechanism and kinetic of hydrolysis of DMTLT are obtained confirming both the usefulness of CE-MS to characterize new biomaterials and the applicability of DMTLT for preparing new biodegradable polymers. These results are corroborated through the CE-MS detection of the identified products of degradation in a dimethyl acrylamide polymer cross-linked with DMTLT. 相似文献
166.