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31.
Carolina Resmini Melo Elidio Angioletto Humberto Gracher Riella Michael Peterson Márcio Roberto Rocha Aline Resmini Melo Luciano Silva Susane Strugale 《Journal of Thermal Analysis and Calorimetry》2012,109(3):1341-1345
Research focused on the transformation and utilization of industrial wastes into products of commercial interest plays an increasingly important role. Residual pulp can become useful in the manufacture of different materials, providing high value to this waste and reducing its environmental impact when disposed of improperly in the environment. The main constituents of this waste are kaolin and calcium carbonate (CaCO3). Starting from kaolin, metakaolin can be produced by calcination of the residue at 630?°C for 2?h in a rotary reactor with air flow, followed by solubilization with hydrochloric acid to remove the CaCO3. The development of technological alternatives aimed at the reuse of certain wastes can result in applications of real economic interest to the chemical industry and ceramics and glass, which is the case in this study. The raw material and metakaolin obtained were analyzed by thermogravimetric analysis and derivative thermogravimetric analysis, X-ray diffraction, and X-ray fluorescence spectroscopy with promising results. This is because metakaolin was obtained free of contamination by other materials. 相似文献
32.
The use of light front coordinates in quantum field theories (QFT) always brought some problems and controversies. In this work we explore some aspects of its formalism with respect to the employment of dimensional regularization in the computation of the photon’s self-energy at the one-loop level and how the fermion propagator has an important role in the outcoming results. 相似文献
33.
In conformational analysis, the systematic search method completely maps the space but suffers from the combinatorial explosion problem because the number of conformations increases exponentially with the number of free rotation angles. This study introduces a new methodology of conformational analysis that controls the combinatorial explosion. It is based on a dimensional reduction of the system through the use of principal component analysis. The results are exactly the same as those obtained for the complete search but, in this case, the number of conformations increases only quadratically with the number of free rotation angles. The method is applied to a series of three drugs: omeprazole, pantoprazole, lansoprazole-benzimidazoles that suppress gastric-acid secretion by means of H+, K+-ATPase enzyme inhibition. 相似文献
34.
S.?Soriano T.?Gourieux A.?Stunault K.?Dumesnil C.?DufourEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2005,48(2):167-171
In order to determine the strain tensor in a 375 nm thick Eu(110) epitaxial thin film, we have developed a new method, based
on the accurate determination of the lattice vectors by high resolution X-ray diffraction. We show that a biaxial strain model
gives a good representation
of the state of the strains field in the film. 相似文献
35.
Although the classical Fractional Brownian Motion is often used to describe porosity,
it is not adapted to anisotropic situations. In the present work, we study a class of Gaussian
fields with stationary increments and spectral density. They present asymptotic self-similarity
properties and are good candidates to model a homogeneous anisotropic material, or its radiographic
images. Unfortunately, the paths of all Gaussian fields with stationary increments have the
same apparent regularity in all directions (except at most one). Hence we propose here a procedure
to recover anisotropy from one realization: computing averages over all the hyperplanes which
are orthogonal to a fixed direction, we get a process whose Hölder regularity depends explicitly on
the asymptotic behavior of the spectral density in this direction. 相似文献
36.
M. M. Cavalcanti V. N. Domingos Cavalcanti J. A. Soriano L. A. Medeiros 《Southeast Asian Bulletin of Mathematics》2000,24(2):183-199
In this paper, we study a hyperbolic model based on the equation
with nonlinear boundary conditions given by
.We prove the existence and the uniqueness of global solutions. Also, we obtain the uniform decay of the energy without control of its derivative sign.AMS Subject Classification (2000), 35L05, 35L70, 35B40 相似文献
37.
Core-level electronic properties of nanostructured NiO coatings 总被引:1,自引:0,他引:1
Nanostructured NiO films with different thicknesses were grown on nanoporous alumina membrane substrates by reactive evaporation of Ni in an oxygen atmosphere. The reactive deposition process was assisted by a low energy oxygen ion-beam in order to increase the NiO input into the pores. Surface morphology and structure of the films were analyzed by SEM and XPS. SEM observations reveal a well adhered film of NiO on the substrate. This film appears to be uniform and presents a rather irregular nanostructured morphology, built of NiO clusters with sizes ranging between 5 and 30 nm. The core-level electronic properties of this nanostructured NiO film result to be similar to those of an ultrathin film about one monolayer thick. This behaviour can be explained by the large surface to volume ratio of both systems. 相似文献
38.
Aline Lima de Oliveira Carlos Henrique Alves de Oliveira Laura Maia Mairink Francine Pazini Ricardo Menegatti Luciano Morais Lião 《Magnetic resonance in chemistry : MRC》2011,49(8):537-542
Complete assignment of 1H and 13C NMR chemical shifts and J(1H/1H and 1H/19F) coupling constants for 22 1‐phenyl‐1H‐pyrazoles' derivates were performed using the concerted application of 1H 1D and 1H, 13C 2D gs‐HSQC and gs‐HMBC experiments. All 1‐phenyl‐1H‐pyrazoles' derivatives were synthesized as described by Finar and co‐workers. The formylated 1‐phenyl‐1H‐pyrazoles' derivatives were performed under Duff's conditions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
39.
Allan N. Soriano Bonifacio T. Doma Meng-Hui Li 《The Journal of chemical thermodynamics》2009,41(3):301-307
Correlations between density and refractive index of pure systems of ionic liquids were examined in this work. To this end, the density and refractive index of four 1-n-butyl-3-imidazolium-based ionic liquids were measured at atmospheric pressure and temperature up to 353.2 K. Densities and refractive indices of the ionic liquids investigated are presented as a function of temperature. A group contribution-based equation was modified to calculate the density as a function of temperature. An empirical equation was used to study the temperature-dependence of refractive index. The Lorentz–Lorenz, Dale–Gladstone, Eykman, Oster, Arago–Biot, and Newton equations, as well as a modified Eykman were used to correlate the relation between the densities and refractive indices of the different ionic liquid systems. The correlations give satisfactory results. The results of this study can add to the newly organized database for ionic liquids and can also be used for various process design calculations. 相似文献
40.