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141.
Sonia de Almeida Giseli Bernabé Marisa S. Crespi Clóvis A. Ribeiro Evaneide Nascimento Lima 《Journal of Thermal Analysis and Calorimetry》2011,105(2):461-465
The organic fraction of urban solid residues disposed of in sanitary landfills during the decomposition yields biogas and
leachate, which are sources of pollution. Leachate is a resultant liquid from the decomposition of substances contained in
solid residues and it contains in its composition organic and inorganic substances. Literature shows an increase in the use
of thermoanalytical techniques to study the samples with environmental interest, this way thermogravimetry is used in this
research. Thermogravimetric studies (TG curves) carried out on leachate and residues shows similarities in the thermal behavior,
although presenting complex composition. Residue samples were collected from landfills, composting plants, sewage treatment
stations, leachate, which after treatment, were submitted for thermal analysis. Kinetic parameters were determined using the
Flynn–Wall–Ozawa method. In this case they show little divergence between the kinetic parameter that can be attributed to
different decomposition reaction and presence of organic compounds in different phases of the decomposition with structures
modified during degradation process and also due to experimental conditions of analysis. 相似文献
142.
Marco Ovalle Dr. Michael Kathan Dr. Ryojun Toyoda Charlotte N. Stindt Dr. Stefano Crespi Prof. Dr. Ben L. Feringa 《Angewandte Chemie (International ed. in English)》2023,62(9):e202214495
In a chemical equilibrium, the formation of high-energy species—in a closed system—is inefficient due to microscopic reversibility. Here, we demonstrate how this restriction can be circumvented by coupling a dynamic equilibrium to a light-induced E/Z isomerization of an azobenzene imine cage. The stable E-cage resists intermolecular imine exchange reactions that would “open” it. Upon switching, the strained Z-cage isomers undergo imine exchange spontaneously, thus opening the cage. Subsequent isomerization of the Z-open compounds yields a high-energy, kinetically trapped E-open species, which cannot be efficiently obtained from the initial E-cage, thus shifting an imine equilibrium energetically uphill in a closed system. Upon heating, the nucleophile is displaced back into solution and an opening/closing cycle is completed by regenerating the stable all-E-cage. Using this principle, a light-induced cage-to-cage transformation is performed by the addition of a ditopic aldehyde. 相似文献
143.
Dr. Ayelén F. Crespi Dr. Daniel Vega Dr. Ana L. Pérez Dr. Enrique Rodríguez-Castellón Dr. Juan M. Lázaro-Martínez 《欧洲无机化学杂志》2023,26(9):e202200737
Novel coordination compounds, mono- ( 1 ) and binuclear copper complexes ( 2 ) and a zinc complex ( 3 ) were synthesized and studied through single-crystal X-ray crystallography, solid-state NMR and EPR techniques to determine the chemical functionalization of the carbonyl group in N-methyl-2-imidazolecarboxaldehyde ligand. Particularly, molecules containing carbonyl groups are versatile ligands that give rise to a wide range of new materials due to the high reactivity of the carbonyl group. However, the chemical identification of the functional group present in these coordination compounds is a challenge because the copper ion affects the NMR signals. In this sense, X-ray crystallography becomes an indispensable tool for the analysis. The imidazole ligands in copper complexes 1 and 2 were found to be the aldehyde and the gem-diol forms, respectively. Furthermore, the gem-diol and carboxylate moieties were detected in the crystal lattice for the zinc complex 3 and studied by solution- and solid-state NMR. 相似文献
144.
Wieland O Bracco A Camera F Benzoni G Blasi N Brambilla S Crespi F Giussani A Leoni S Mason P Million B Moroni A Barlini S Kravchuk VL Gramegna F Lanchais A Mastinu P Maj A Brekiesz M Kmiecik M Bruno M Geraci E Vannini G Casini G Chiari M Nannini A Ordine A Ormand E 《Physical review letters》2006,97(1):012501
The gamma decay of the giant dipole resonance (GDR) in the 132Ce compound nucleus with temperature up to approximately 4 MeV has been measured, using the reaction 64Ni + 68Zn at E(beam) = 300, 400, and 500 MeV. The gamma and charged particles measured in coincidence with recoils are consistent with a fully equilibrated compound nucleus emission. The GDR width, obtained with the statistical model analysis, is found to increase almost linearly with temperature. This increase is rather well reproduced within a model including thermal shape fluctuations and the lifetime of the compound nucleus. 相似文献
145.
Vívian Aparecida Ricardo Teixeira Ernesto Clóvis Augusto Ribeiro Ossamu Hojo Fernando Luis Fertonani Marisa Spirandeli Crespi 《Journal of Thermal Analysis and Calorimetry》2009,97(2):653-656
Bagasse samples from four different sugarcane were directly collected as the residues of milling in a processing plant. The
samples were dried at 105 °C, compressed to small granules and then their TG/DTA and DSC curves in synthetic air were recorded.
Similar thermogravimetric curves were obtained for the different samples and they exhibited four mass loss steps. However,
the analysis of the exotherm DSC peaks showed that the oxidation of the organic matter resulted different enthalpy values
(ΔH/kJ g−1). 相似文献