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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
54.
Chlorofluorocarbons and their substitutes are anthropogenic compounds strongly involved in global change phenomena. Therefore, their atmospheric mixing-ratios are monitored on a worldwide scale. In order to evaluate source strength of these compounds in Southern Europe, in 1999 a research activity, monitoring these compounds in the atmosphere of the Monte Cimone (MO, Italy) was started. Air samples, collected on a weekly base, were analyzed using a GC-MS methodology recently devised by our group. The reported results, obtained after eighteen months of observation, are relative to four fully halogenated halocarbons and four hydrogenated halocarbons. 相似文献
55.
We describe the characteristics of a double-exposure specklegram obtained through a double-aperture system, by introduction of a wedge in front of one aperture in one exposure. It is assumed that a uniform displacement of the diffuser is produced between exposures. The average intensity distribution and visibility of the interferometric fringes in the Fourier plane are analyzed. An alternative interferometric technique for phase-object detection is proposed. 相似文献
56.
Luciano Lombardo 《Tetrahedron letters》1985,26(3):381-384
The successful entry to the diverse mixed vinylketene acetals 3 extends the participation of these intermediates in cyclohexenone synthesis. 相似文献
57.
Rita Menicagli Corrado Malanga Luciano Lardicci Laura Tinucci 《Tetrahedron letters》1980,21(47):4525-4528
2-Ethoxy-5-alkyl-3,4-dihydro-2H-pyrans react with Albui3 and through a regioselective hydride addition provide substituted cyclobutylmethanols in very good yields. 相似文献
58.
Luciano Carbone 《Rendiconti del Circolo Matematico di Palermo》1979,28(1):115-133
We give some solution existence and uniqueness theorems for the Volterra type equations systems (1) and (6). 相似文献
59.
We examine the contribution of pairing fluctuations to the superfluid order parameter for harmonically trapped atomic Fermi gases in the BCS regime. In the limit of small systems we consider, both analytically and numerically, their space and temperature dependence. We predict a parity effect, i.e., that pairing fluctuations show a maximum or a minimum at the center of the trap, depending on the value of the last occupied shell being even or odd. We propose to detect pairing fluctuations by measuring the density-density correlation function after a ballistic expansion of the gas. 相似文献
60.
Ignacio?García-JuradoEmail author Luciano?Méndez-Naya César?Sánchez-Sellero 《Mathematical Methods of Operations Research》2004,59(3):349-357
In this note we show that the mathematical tools of cooperative game theory allow a successful approach to the statistical problem of estimating a density function. Specifically, any random sample of an absolutely continuous random variable determines a transferable utility game, the Shapley value of which proves to be an estimator of the density function of binned kernel and WARPing types, with good computational and statistical properties.Authors acknowledge the financial support of Spanish Ministry for Science and Technology and FEDER through projects BFM2002-03213 and BEC2002-04102-C02-02 and of Xunta de Galicia through projects PGIDT00PXI20104PR and PGIDT03PXIC20701PN. They also thank the comments of two anonymous referees. 相似文献