Abstract:

Informe original mecanografiado. Escaneo de mediana calidad. Incluye mapa, fotografías, gráficos y bibliografía.

Author affiliation: González, Osvaldo Edgar. Dirección Nacional de Minería. Secretaría de Industria y Minería, Ministerio de Economía; Argentina

Abstract:

One of the problems that mining represents in relation to the natural watercourses is the possible formation of what we call acid mine drainage, which consists in the emission or formation of water effluents of great acidity, usually rich in sulfate and with variable contents in heavy metals. The drainage mentioned is developed from the metal sulfide and sulfate leaching. Researches about the creation of acid drainage suggest that the formation of these depends directly on various factors: primary mineralogy (neutralizer sulfides and minerals), water presence (whether), oxygen diffusion, grain size, microbiological interaction (bacterium), among others. To study these variables and to relate them with geological factors, static (Acid-Base Accounting) and dynamic (Humidity Cell) tests have been developed, among others. The mentioned tests are applied to a case of a gold deposit situated in the Province of San Juan, which is currently very argued because of its mining activity due to its leaching process. In the sterile mineral obtained from the process, kinetics tests were carried out in humidity cells to simulate the natural oxidation of the primary mineral samples. In the obtained leaching, pH values closer to neutrality and a limited solution metal presence were detected, indicating the neutralization ability due to the carbonates ores presence.

Author affiliation: Bazan Brizuela, Vanesa Lucia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Sarquis, Pedro Edgardo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina

Author affiliation: Brandaleze, Elena. Universidad Tecnológica Nacional. Facultad Regional San Nicolás; Argentina

Abstract:

A green synthetic approach for dimethyl isosorbide (DMI) with dimethylcarbonate (DMC) in the presence of a base is reported. The easy methylation of isosorbide may be due to its unique structure (which enhances the nucleophilicity of the hydroxyl groups), and to the effect of the hydrogen bonding which increases the reactivity of the molecule towards DMC.

Author affiliation: Tundo, Pietro. Universita' Ca' Foscari Di Venezia; Italia. Interuniversity Consortium Chemistry for the Environment; Italia

Author affiliation: Aricò, Fabio. Interuniversity Consortium Chemistry for the Environment; Italia. Universita' Ca' Foscari Di Venezia; Italia

Author affiliation: Gauthier, Guillaume. École Nationale Supérieure de Chimie de Paris; Argentina

Author affiliation: Rossi, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina

Author affiliation: Rosamilia, Anthony E.. Interuniversity Consortium Chemistry for the Environment; Italia

Author affiliation: Bevinakatti, Hanamanthsa S.. Uniqema; Reino Unido

Author affiliation: Sievert, Robert L.. Uniqema; Reino Unido

Author affiliation: Newman, Christoper P.. Quest International; Reino Unido

Abstract:

Current medical treatments against recurrent pulmonary infections caused by Pseudomonas aeruginosa, such as cystic fibrosis (CF) disorder, involve the administration of inhalable antibiotics. The main challenge is, however, the eradication of microbial biofilms immersed in dense mucus that requires high and recurrent antibiotic doses. Accordingly, the development of novel drug delivery systems capable of providing local and controlled drug release in the lungs is a key factor to improve the therapeutic outcome of such therapeutic molecules. Inhalable hybrid carriers were prepared by co-precipitation of CaCO3 in the presence of alginate and the resulting microparticles were treated with alginate lyase (AL) in order to modify their porosity and enhance the drug loading. The hybrid microparticles were loaded with DNase (mucolytic agent) and levofloxacin (LV, wide-spectrum antibiotic) in the range of 20-40% for LV and 28-67% for DNase, depending on the AL treatment. In vitro studies demonstrated that microparticles were able to control the DNase release for 24 h, while 30-50% of LV was released in 3 days. The morphological characterization was performed by optical, fluorescence and scanning electron microscopies, showing a narrow size distribution (5 mm). FTIR, XRD, DSC and nitrogen adsorption isotherm studies revealed the presence of the drugs in a non-crystalline state. A microcidal effect of microparticles was found on P. aeruginosa in agar plates and corroborated by Live/Dead kit and TEM observations. Finally, to study whether the microparticles improved the localization of LV in the lungs, in vivo studies were performed by pulmonary administration of microparticles to healthy mice via nebulization and dry powder inhalation, followed by the quantification of LV in lung tissue. The results showed that microparticles loaded with LV delivered the antibiotic at least 3 times more efficiently than free LV. The developed system opens the gateway to new drug delivery systems that may provide enhanced therapeutic solutions against bacterial infections and in particular as a potential tool in CF pathology.

Author affiliation: Islan, German Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina

Author affiliation: Ruiz, María Esperanza. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Morales, Juan Francisco. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Sbaraglini, Maria Laura. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Enrique, Andrea Verónica. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Burton, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; Argentina

Author affiliation: Talevi, Alan. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Bruno Blanch, Luis Enrique. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina

Author affiliation: Castro, Guillermo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina

Abstract:

Two sets of Ni-substituted calcium phosphate were synthesized by precipitation method at pH = 7 and at two different concentrations of ion carbonate (CO3 2-) in solution and Ni(II) concentrations lower than 15%. The produced solids were characterized by chemical analysis, infrared spectroscopy, x-ray powder diffraction and scanning electron microscopy. The solid samples obtained at low concentration of CO3 2- (5%) and Ni(II) concentrations 5%, 10% and 15% were synthesized at 25 and 37 °C. All solids showed the presence of a stable and crystalline brushite (CaHPO4·2H2O). The samples synthesized in presence of high levels of carbonate (50%) and Ni(II) concentration 5% at 25, 37 and 100 °C vary with temperature. Those obtained at the lower temperatures (25 and 37 °C) showed coexistence of two phases: a crystalline CaCO3 and carbonate apatite with low crystallinity. At 100 °C, only carbonate apatite could be recognized. Data supported the carbonate substitution by OH- (position A) and PO4 3- (position B) in the hydroxyapatite structure. The comparison of the chemical analysis results of both systems studied (Ni,Ca) apatite and (Ni,Ca) carbonate apatite evidences a rise of Ni(II) incorporation in the apatite lattice, with simultaneous inclusion of CO3 2- and temperature increase. The obtained results suggest that brushite kidney stones development may be induced by the presence of traces of Ni(II) and simultaneous decrease of carbonate levels in the biological fluids.

Author affiliation: Guerra López, José Rodolfo. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina

Author affiliation: Guida, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

Author affiliation: Bianchi, Ana Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina

Author affiliation: Punte, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina

Abstract:

Author affiliation: Palacio, Andrés H. Ministerio de Economía. Subsecretaría de Minería. Servicio Nacional Geológico Minero; Argentina.

Incluye fotos

Informe sobre yacimientos de Carbonato de Sodio dirigido a Juan D. Perón (1973)

Abstract:

In order to modified the acid-base properties of pure cerium dioxide, a series of ceria-based oxides doped with gallium(III) cations (from 5 to 50% mol/mol of Ga) was prepared by co-precipitation in basic aqueous solution followed by calcination at 773 K. N 2 physisorption at 77 K showed that mesoporous materials with surface areas between 75 and 104 m 2/g were obtained. Ga(III) cations were incorporated into the ceria crystal structure up to a concentration close to 20-25% mol/mol of Ga, as revealed by powder X-ray diffraction analysis. Surface basicity was investigated using CO 2 chemisorption by mass spectrometry and in situ infrared spectroscopy. A progressive decrease in the surface basicity in the series of ceria-gallia materials was observed as the Ga content increases. Different carbonate and bicarbonate surface species were identified through their vibrational infrared modes. A remarkable decrease in the surface stability of carbonate species, particularly of the polydentate carbonate groups, was detected, which is correlated to the incorporation of gallium(III) into the ceria lattice.

Author affiliation: Finos, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Author affiliation: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Author affiliation: Blanco, Ginesa. Universidad de Cádiz; España

Author affiliation: Del Rio, Eloy. Universidad de Cádiz; España

Author affiliation: Cíes, José María. Universidad de Cádiz; España

Author affiliation: Bernal, Serafín. Universidad de Cádiz; España

Author affiliation: Bonivardi, Adrian Lionel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Abstract:

This study examines the development of an integrated process for separation and purification of low grade talc ores. This procedure involves leaching with HCl to dissolve gangue minerals and to purify a low purity talc ore containing up to 40% gangue minerals. Also, all cations from gangue minerals are recovered as hydroxides via selective precipitation. The effects of acid concentration, talc/acid solution ratio, time, and reaction temperature on talc purification were studied and the optimal conditions were determined. Laboratory-scale tests revealed that the resulting talc is free of gangue minerals, consisting of small particles with nanometric thicknesses. Reactants are fully consumed during dissolution and byproducts like ammonium chloride could be recirculated and reused. Resulting hydroxides can be used as a coagulation aid for water treatment.

Author affiliation: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Author affiliation: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Author affiliation: Maiza, Pedro Jose. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Capiati, Daniela Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Abstract:

This study examines the development of an integrated process for separation and purification of low grade talc ores. This procedure involves leaching with HCl to dissolve gangue minerals and to purify a low purity talc ore containing up to 40% gangue minerals. Also, all cations from gangue minerals are recovered as hydroxides via selective precipitation. The effects of acid concentration, talc/acid solution ratio, time, and reaction temperature on talc purification were studied and the optimal conditions were determined. Laboratory-scale tests revealed that the resulting talc is free of gangue minerals, consisting of small particles with nanometric thicknesses. Reactants are fully consumed during dissolution and byproducts like ammonium chloride could be recirculated and reused. Resulting hydroxides can be used as a coagulation aid for water treatment.</p> <p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; TEXT-INDENT: 35.4pt; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class="MsoNormal"> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p></p></span> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p>

Author affiliation: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Author affiliation: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Author affiliation: Maiza, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentina

Author affiliation: Capiati, Numa Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Abstract:

This study examines the development of an integrated process for separation and purification of low grade talc ores. This procedure involves leaching with HCl to dissolve gangue minerals and to purify a low purity talc ore containing up to 40% gangue minerals. Also, all cations from gangue minerals are recovered as hydroxides via selective precipitation. The effects of acid concentration, talc/acid solution ratio, time, and reaction temperature on talc purification were studied and the optimal conditions were determined. Laboratory-scale tests revealed that the resulting talc is free of gangue minerals, consisting of small particles with nanometric thicknesses. Reactants are fully consumed during dissolution and byproducts like ammonium chloride could be recirculated and reused. Resulting hydroxides can be used as a coagulation aid for water treatment.</p> <p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; TEXT-INDENT: 35.4pt; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class="MsoNormal"> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p></p></span> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p>

Author affiliation: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Author affiliation: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Author affiliation: Maiza, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Geología; Argentina

Author affiliation: Capiati, Numa Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina