Different ratios of solid binary mixtures of quartz, calcite, kaolinite, and illite were prepared... more Different ratios of solid binary mixtures of quartz, calcite, kaolinite, and illite were prepared by analytical balance: 5/95, 25/75, 50/50, 75/25, 95/5. These powder mixtures were analyzed using a Rigaku Rint 2200 instrument with a conventional Bragg-Brentano geometry equipped with a copper tube and a graphite crystal monochromator. The data were collected in the angular range 3-100 2θ with steps of 0.02 and 5 s/step. The data collections were converted into GSAS files for EXPGUI software and quantitatively refined by Rietveld method. These refinements and weight amounts were used as references for the following data collections.
This paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffract... more This paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffraction) study of cancrinite-group minerals of relevance to alkaline igneous rocks. A solid solution is known to exist between cancrinite and vishnevite with the principal substitutions being CO3 2- by SO4 2- and Ca for Na. In the present study, several intermediate members of the cancrinite–vishnevite series from a syenitic intrusion at Cinder Lake (Manitoba, Canada), were used to examine how chemical variations in this series affect their spectroscopic and structural characteristics. The Cinder Lake samples deviate from the ideal cancrinite-vishnevite binary owing to the presence of cation vacancies. The only substituent elements detectable by electron microprobe are K, Sr and Fe (0.03-0.70, 0-0.85 and 0-0.45 wt.% respective oxides). The following Raman bands are present in the spectra of these minerals: ∼631 cm-1 and ∼984-986 cm-1 [SO4 2- vibration modes]; ∼720-774 cm -1 and ∼1045-1060 cm...
... crystal chemistry and XANES spectroscopy Maria Franca BRIGATTI 1 ,* , Ermanno GALLI 1 , Luca ... more ... crystal chemistry and XANES spectroscopy Maria Franca BRIGATTI 1 ,* , Ermanno GALLI 1 , Luca MEDICI 1 , Luciano POPPI 1 ... A sample occurs within biotite schist at Campbell Creek, whereas the other sample occurs in mica layers of a quartz-schist at Anatoki River Go ...
ABSTRACT Combinations of different molecules usually co-exuded by plant roots in soil can signifi... more ABSTRACT Combinations of different molecules usually co-exuded by plant roots in soil can significantly affect the mobilization of mineral elements from soil. The flavonoids rutin and quercetin appeared to be highly efficient in Fe and Mn mobilization from soil, being rutin about 25 times more effective than citrate in extracting Fe from an alkaline calcareous soil, and 15 times in mobilizing Mn from a slight acidic agricultural soil. Quercetin was particularly effective in mobilizing Mn from the acidic soil and 50 times more efficient than citrate. A significant synergistic effect was detected when either quercetin or rutin was combined with citrate, extracting, respectively, 1.7 and 1.5 times more Mn than what is expected by a simple combination of the two. Sorption processes on soil particles were more relevant for flavonoids than for organic acids for which microbial degradation often prevails, with the only exception of oxalate. Citrate was usually the most efficient organic acid in mobilizing major and trace elements from soil even if oxalate was a better extractant for Cu, Zn, and Ni from the alkaline soil. In the acid soil, a synergistic effect among organic acids was observed only for Mn while in alkaline soil it was observed for Si. The mechanism by which Fe is extracted by rutin in the alkaline soil is a reductive one, with one molecule of rutin being capable of mobilizing two atoms of Fe. Also for Mn in the acid soil, quercetin and rutin solubilize this element by a reductive process. However, when quercetin and rutin are combined with citrate, a complex-forming dissolution mechanism also occurs which increases the mobilization of Mn over the expected rates.
ABSTRACT Two-phase zirconium boride thin films have been obtained by ultra-short pulsed laser abl... more ABSTRACT Two-phase zirconium boride thin films have been obtained by ultra-short pulsed laser ablation (PLA) of azirconium dodecaboride (ZrB12) target performed in vacuum. The ablation source was a frequency dou-bled (� = 527 nm) Nd:glass laser with a pulse duration of 250 fs. Laser induced plasma has been studied byICCD imaging and time and space resolved optical emission spectroscopy (OES), whereas the depositedfilms have been characterized by atomic force microscopy, scanning electron microscopy, X-Ray diffrac-tion and micro-Raman spectroscopy. The film morphology and composition have been interpreted onthe basis of the laser ablation mechanism.
... Diclofenac-hydrotalcite: In vitro and in vivo release experiments. Francesco Paolo Bonina a ,... more ... Diclofenac-hydrotalcite: In vitro and in vivo release experiments. Francesco Paolo Bonina a , Maria Luigia Giannossi b , Luca Medici b , Corresponding Author Contact Information , E-mail The Corresponding Author , Carmelo Puglia a , Vito Summa b and Fabio Tateo c. ...
The work deals the interactions between two commercial clays, a bentonite and a kaolin, and an ir... more The work deals the interactions between two commercial clays, a bentonite and a kaolin, and an iron-salicylate complex. Adsorption experiments were accomplished using a water solution containing Fe(III) 0.0176 M and salicylic acid 0.0253 M. Natural and treated clay samples were characterized by chemical analyses, powder X-ray diffraction, thermal analyses. The time dependence of salicylic acid adsorption by bentonite follows first-order kinetics, with respect to the percentage of salicylic acid adsorbed, in the first 12 h; afterwards the reaction slows down. The reaction is completely exhausted after 2 days and during the next 4 days the concentration of salicylic acid in bentonite does not change from its asymptotic value of 8.0%. The adsorption kinetics of salicylic acid by kaolin highlights a slow adsorption beginning after the fourth day of treatment, and finished after 19 days. The amount of salicylic acid adsorbed was 5.5% of the final complex. The release of salicylic acid adsorbed by bentonite and kaolin was tested in 0.2 N solutions of Na+, K+, Mg2+, and Ca2+. Salicylic acid release rates from Fe(III)-salicylate-containing bentonite were also measured through cellulose acetate membranes by means of Franz-type diffusion cells: an initial slow release of salicylic acid was followed by a fast release phase; after 23 h the concentration of salicylic acid released can be considered constant and the drug desorbed was 1.4% of the amount adsorbed by the bentonite. Even if the desorbed amount of salicylic acid is not very high, the bentonite–salicylate complex could be suitable for an application by gradual release.
Different ratios of solid binary mixtures of quartz, calcite, kaolinite, and illite were prepared... more Different ratios of solid binary mixtures of quartz, calcite, kaolinite, and illite were prepared by analytical balance: 5/95, 25/75, 50/50, 75/25, 95/5. These powder mixtures were analyzed using a Rigaku Rint 2200 instrument with a conventional Bragg-Brentano geometry equipped with a copper tube and a graphite crystal monochromator. The data were collected in the angular range 3-100 2θ with steps of 0.02 and 5 s/step. The data collections were converted into GSAS files for EXPGUI software and quantitatively refined by Rietveld method. These refinements and weight amounts were used as references for the following data collections.
This paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffract... more This paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffraction) study of cancrinite-group minerals of relevance to alkaline igneous rocks. A solid solution is known to exist between cancrinite and vishnevite with the principal substitutions being CO3 2- by SO4 2- and Ca for Na. In the present study, several intermediate members of the cancrinite–vishnevite series from a syenitic intrusion at Cinder Lake (Manitoba, Canada), were used to examine how chemical variations in this series affect their spectroscopic and structural characteristics. The Cinder Lake samples deviate from the ideal cancrinite-vishnevite binary owing to the presence of cation vacancies. The only substituent elements detectable by electron microprobe are K, Sr and Fe (0.03-0.70, 0-0.85 and 0-0.45 wt.% respective oxides). The following Raman bands are present in the spectra of these minerals: ∼631 cm-1 and ∼984-986 cm-1 [SO4 2- vibration modes]; ∼720-774 cm -1 and ∼1045-1060 cm...
... crystal chemistry and XANES spectroscopy Maria Franca BRIGATTI 1 ,* , Ermanno GALLI 1 , Luca ... more ... crystal chemistry and XANES spectroscopy Maria Franca BRIGATTI 1 ,* , Ermanno GALLI 1 , Luca MEDICI 1 , Luciano POPPI 1 ... A sample occurs within biotite schist at Campbell Creek, whereas the other sample occurs in mica layers of a quartz-schist at Anatoki River Go ...
ABSTRACT Combinations of different molecules usually co-exuded by plant roots in soil can signifi... more ABSTRACT Combinations of different molecules usually co-exuded by plant roots in soil can significantly affect the mobilization of mineral elements from soil. The flavonoids rutin and quercetin appeared to be highly efficient in Fe and Mn mobilization from soil, being rutin about 25 times more effective than citrate in extracting Fe from an alkaline calcareous soil, and 15 times in mobilizing Mn from a slight acidic agricultural soil. Quercetin was particularly effective in mobilizing Mn from the acidic soil and 50 times more efficient than citrate. A significant synergistic effect was detected when either quercetin or rutin was combined with citrate, extracting, respectively, 1.7 and 1.5 times more Mn than what is expected by a simple combination of the two. Sorption processes on soil particles were more relevant for flavonoids than for organic acids for which microbial degradation often prevails, with the only exception of oxalate. Citrate was usually the most efficient organic acid in mobilizing major and trace elements from soil even if oxalate was a better extractant for Cu, Zn, and Ni from the alkaline soil. In the acid soil, a synergistic effect among organic acids was observed only for Mn while in alkaline soil it was observed for Si. The mechanism by which Fe is extracted by rutin in the alkaline soil is a reductive one, with one molecule of rutin being capable of mobilizing two atoms of Fe. Also for Mn in the acid soil, quercetin and rutin solubilize this element by a reductive process. However, when quercetin and rutin are combined with citrate, a complex-forming dissolution mechanism also occurs which increases the mobilization of Mn over the expected rates.
ABSTRACT Two-phase zirconium boride thin films have been obtained by ultra-short pulsed laser abl... more ABSTRACT Two-phase zirconium boride thin films have been obtained by ultra-short pulsed laser ablation (PLA) of azirconium dodecaboride (ZrB12) target performed in vacuum. The ablation source was a frequency dou-bled (� = 527 nm) Nd:glass laser with a pulse duration of 250 fs. Laser induced plasma has been studied byICCD imaging and time and space resolved optical emission spectroscopy (OES), whereas the depositedfilms have been characterized by atomic force microscopy, scanning electron microscopy, X-Ray diffrac-tion and micro-Raman spectroscopy. The film morphology and composition have been interpreted onthe basis of the laser ablation mechanism.
... Diclofenac-hydrotalcite: In vitro and in vivo release experiments. Francesco Paolo Bonina a ,... more ... Diclofenac-hydrotalcite: In vitro and in vivo release experiments. Francesco Paolo Bonina a , Maria Luigia Giannossi b , Luca Medici b , Corresponding Author Contact Information , E-mail The Corresponding Author , Carmelo Puglia a , Vito Summa b and Fabio Tateo c. ...
The work deals the interactions between two commercial clays, a bentonite and a kaolin, and an ir... more The work deals the interactions between two commercial clays, a bentonite and a kaolin, and an iron-salicylate complex. Adsorption experiments were accomplished using a water solution containing Fe(III) 0.0176 M and salicylic acid 0.0253 M. Natural and treated clay samples were characterized by chemical analyses, powder X-ray diffraction, thermal analyses. The time dependence of salicylic acid adsorption by bentonite follows first-order kinetics, with respect to the percentage of salicylic acid adsorbed, in the first 12 h; afterwards the reaction slows down. The reaction is completely exhausted after 2 days and during the next 4 days the concentration of salicylic acid in bentonite does not change from its asymptotic value of 8.0%. The adsorption kinetics of salicylic acid by kaolin highlights a slow adsorption beginning after the fourth day of treatment, and finished after 19 days. The amount of salicylic acid adsorbed was 5.5% of the final complex. The release of salicylic acid adsorbed by bentonite and kaolin was tested in 0.2 N solutions of Na+, K+, Mg2+, and Ca2+. Salicylic acid release rates from Fe(III)-salicylate-containing bentonite were also measured through cellulose acetate membranes by means of Franz-type diffusion cells: an initial slow release of salicylic acid was followed by a fast release phase; after 23 h the concentration of salicylic acid released can be considered constant and the drug desorbed was 1.4% of the amount adsorbed by the bentonite. Even if the desorbed amount of salicylic acid is not very high, the bentonite–salicylate complex could be suitable for an application by gradual release.
Uploads