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Miguel Vicente

Bio: Miguel Vicente is an academic researcher from University of Salamanca. The author has contributed to research in topics: Catalysis & Saponite. The author has an hindex of 48, co-authored 262 publications receiving 8430 citations. Previous affiliations of Miguel Vicente include Federal University of Paraná & Universidad Pública de Navarra.
Topics: Catalysis, Saponite, FtsZ, Adsorption, FtsA


Papers
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Journal ArticleDOI
TL;DR: In this paper, the effect of the main operating conditions on the performance of photo-Fenton-like advanced oxidation for wastewater treatment, employing either model/synthetic effluents or real streams, is reviewed.
Abstract: Due to their excellent properties, pillared clays (PILCs) have been widely used in several applications, particularly in catalysis. In this paper, their use in heterogeneous photo-Fenton-like advanced oxidation for wastewater treatment, employing either model/synthetic effluents or real streams, is reviewed. Particular attention is given to the effect that the main operating conditions have on process performance, namely wavelength of the light source and power, initial H2O2 or parent compound concentration, catalyst load, pH and temperature. Emphasis is also given to the type of catalyst used and its synthesis conditions (e.g. thermal aging or acid treatment). Several important technological aspects that should be accounted for in real practice are also discussed in detail, particularly the catalyst stability, the use of continuous-flow fixed-bed reactors, the mode of oxidant addition, the environmental impact/integration with biological processes and the possibility of using visible light instead of UV only. Then, some simple mechanistic studies reported are summarized, as well as modeling works.

597 citations

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TL;DR: In this article, a review of the latest results obtained when introducing modifications in the chemical aspects of PILC synthesis are reviewed, including using coordination or organometallic compounds, polymers and surfactants, and acid-activated clays.
Abstract: New methods have been developed in recent years that are now being successfully applied in the preparation of pillared interlayered clays (PILCs). Variations in the procedures concern different parameters involved in the synthesis, such as the starting clay, the intercalating solution, the intercalation process, and the drying and calcination steps of the pillared solids, among others. In the present article, the latest results obtained when introducing modifications in the chemical aspects of PILC synthesis are reviewed. These include (1) pillaring with mixed solutions containing two or more cations, (2) using coordination or organometallic compounds, (3) using polymers and surfactants, (4) pillaring of acid-activated clays, and (5) enhancement of PILC acidity. A separate section is devoted to the specific features of preparing these solids in amounts large enough to make their manufacture on an industrial scale economically feasible. Recent developments in the catalytic applications of PILCs are also re...

491 citations

Journal ArticleDOI
TL;DR: In this article, the degradation and mineralization of Orange II solutions using catalysts based on pillared saponite impregnated with several iron salts is reported, achieving 99% of dye degradation with 91% of total organic carbon (TOC) reduction (at 70°C) using only ca. 90mg of clay catalyst per litre of solution.
Abstract: In this work, the degradation and mineralization of Orange II solutions (0.1 mM) using catalysts based on pillared saponite impregnated with several iron salts is reported. Oxidation is carried out in a batch reactor, in presence of various hydrogen peroxide concentrations, and in a wide range of temperature and pH values. Twelve samples are prepared, with three iron loads (7.5, 13.0 and 17.0 wt.%) and four iron salts as precursors, namely Fe(II) acetate, Fe(II) oxalate, Fe(II) acetylacetonate and Fe(III) acetylacetonate. The samples are characterized using X-ray diffraction, thermal analysis, infrared spectroscopy, energy dispersive spectroscopy and adsorption of nitrogen at 77 K. The catalytic results show that these solids present good properties for the degradation and mineralization of Orange II solutions, allowing to reach, in the best conditions and after 4 h of oxidation, 99% of dye degradation with 91% of total organic carbon (TOC) reduction (at 70 °C), using only ca. 90 mg of clay catalyst per litre of solution. Nevertheless, 96% of dye removal with 82% of mineralization are also reached at 30 °C. Besides, the amount of iron released into the final solution is lower than 1 ppm, in the worst of the cases, and 0.09 ppm in the best case.

277 citations

Journal ArticleDOI
TL;DR: In this paper, four metakaolins were prepared by calcination of a natural Spanish kaolin (Navalacruz deposit, Zamora province) at 600, 700, 800, and 900 °C.
Abstract: Four metakaolins were prepared by calcination of a natural Spanish kaolin (Navalacruz deposit, Zamora province) at 600, 700, 800, and 900 °C. These four metakaolins, more reactive than the parent kaolin, were submitted to acid and alkaline activations. Acid activation was carried out with 6 M HCl at room temperature and at 90 °C under reflux conditions, with times of treatment of 6 and 24 h. Treatment at room temperature did not produce any alteration in the structure or in the properties of the metakaolins. Treatment under reflux conditions for 6 h led to the removal of most of the octahedral Al3+ cations, and the formation of an amorphous silica phase, with surface area up to 219 m2/g, because of a high development of both the internal and the external surface of the solids. Acid treatment under stronger conditions (reflux, 24 h) also removed the octahedral cations, but provoked an amorphization of the silica obtained (S ≈ 23 m2/g). The metakaolin prepared by calcination at 900 °C showed a lower reactiv...

270 citations

Journal ArticleDOI
TL;DR: The POTRA domain has attractive features for vaccine development in diseases such as cholera, meningitis, gonorrhoea and syphilis and its function has been experimentally related to polypeptide transport in Toc75 (Tic-Toc protein import system in chloroplast) and ShlB families.

247 citations


Cited by
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01 Jan 2007
TL;DR: The Third edition of the Kirk-Othmer encyclopedia of chemical technology as mentioned in this paper was published in 1989, with the title "Kirk's Encyclopedia of Chemical Technology: Chemical Technology".
Abstract: 介绍了Kirk—Othmer Encyclopedia of Chemical Technology(化工技术百科全书)(第五版)电子图书网络版数据库,并对该数据库使用方法和检索途径作出了说明,且结合实例简单地介绍了该数据库的检索方法。

2,666 citations

Journal ArticleDOI
TL;DR: In this article, the pore size distributions derived from adsorption isotherms of micro- and mesoporous materials are identified and discussed based on new results and examples reported in the recent literature.

1,775 citations

Journal ArticleDOI
TL;DR: A thorough review of alternative non-iron Fenton catalysts and their reactivity towards hydrogen peroxide activation is presented, describing in detail the complex mechanisms and emphasizes on practical limitations influencing their environmental applications.

1,618 citations

Journal ArticleDOI
TL;DR: This review summarizes the present knowledge on the import and sorting of mitochondrial precursor proteins, with a special emphasis on unresolved questions and topics of current research.
Abstract: About 10% to 15% of the nuclear genes of eukaryotic organisms encode mitochondrial proteins. These proteins are synthesized in the cytosol and recognized by receptors on the surface of mitochondria. Translocases in the outer and inner membrane of mitochondria mediate the import and intramitochondrial sorting of these proteins; ATP and the membrane potential are used as energy sources. Chaperones and auxilliary factors assist in the folding and assembly of mitochondrial proteins into their native, three-dimensional structures. This review summarizes the present knowledge on the import and sorting of mitochondrial precursor proteins, with a special emphasis on unresolved questions and topics of current research.

1,324 citations