Thermal,morphostructural and spectrometric characterization of an antibacterial kaolinite-based filter modified with silver for water treatment

Journal of Thermal Analysis and Calorimetry - The aim of this work is to synthesize and characterize a new structured silver–clay dried, calcined or sintered at different temperatures...     

Photoluminescence and Photoacoustic Spectroscopies of Fe3+ in the LiGa5O8–LiGaSiO4–Li5GaSi2O8 System

This report is devoted to the study of the low and room temperature photoluminescence and photoacoustic spectroscopy of the Fe³⁺ impurity ion in the LiGa₅O₈–LiGaSiO₄–Li₅GaSi₂O₈ system. The sample was obtained by solid-state reaction between β-Ga₂O₃, Li₂CO₃, SiO₂ and appropriated quantities of Fe₂O₃. It was investigated by X-ray diffraction to determine the formed phases and through photoluminescence, excitation and photoacoustic spectroscopy measurements. The broad absorption and emission bands in the visible and near-infrared spectral regions presented by that system constitute the motivation for this study. More specifically, the luminescence occurs over a large interval of wavelengths, between 400 nm and 800 nm.     

Comparison between thyroplasty type I andArytenoid rotation: a study of vocal fold vibration using excised human larynges

The purpose of this paper was to compare the vibration of the vocal fold submitted to Isshiki thyroplasty type I (TPI) to that of the contralateral one adducted by the arytenoid rotation (AR) technique. The vocal folds of ten human fresh excised larynges were medialized by TPI on one side and by rotation of the arytenoid on the contralateral side. Laryngeal vibration was artificially produced and was recorded by videostroboscopy. The images were subjectively and objectively analyzed. Subjective analysis included periodicity of vibratory cycles, features of the mucosal wave present on the TPI side, amplitude of vibration, and profile of free border of each vocal fold during the opening phase. Objective analyses were carried out on frame-by-frame digitalized images to determine amplitudes of vibrations and phase differences between the folds in three glottic regions (anterior, middle, and posterior). Subjective analysis revealed regular periodicity in 100% of the larynges, a decrease in the mucosal wave on the TPI side in 70%, reduction in amplitude in 30%, and a sigmoid profile of the free border on the TPI side in 80%. Objective analysis showed mean amplitude in the posterior glottic region on the TPI side significantly larger than that on the arytenoids rotation side and phase asymmetry in 90% of the larynges.     

Ethanol production by a flocculant yeast strain in a CSTR type fermentor with cell recycling

Tests were performed in a continuous stirred tank reactor (CSTR), with and without cell recycling, to produce ethanol. The reactor without cell recycling produced the kinetic model of ethanol production, whereas the reactor with cell recycling allowed for a study of process stability. The Levenspiel kinetic model was adopted; however, in the case of fermentation with cell recycling, the coefficient of cell death was added. It was observed that cellular viability varied greatly throughout the fermenting process and that microaeration is of fundamental importance in maintaining the stability of the process.     

Thermal characterization of lignocellulosic residue from different sugarcanes

Bagasse samples from four different sugarcane were directly collected as the residues of milling in a processing plant. The samples were dried at 105 °C, compressed to small granules and then their TG/DTA and DSC curves in synthetic air were recorded. Similar thermogravimetric curves were obtained for the different samples and they exhibited four mass loss steps. However, the analysis of the exotherm DSC peaks showed that the oxidation of the organic matter resulted different enthalpy values (ΔH/kJ g⁻¹).