Thiago Alessandre da Silva

Efeito do teor de umidade sobre o pré-tratamento a vapor e a hidrólise enzimática do bagaço de cana-de-açúcar

EFFECT OF MOISTURE CONTENT IN THE STEAM TREATMENT AND ENZYMATIC HYDROLYSIS OF SUGARCANE BAGASSE. The effect of moisture content in the steam treatment and enzymatic hydrolysis of sugarcane bagasse was evaluated. Steam treatment was perfomed at 195-210 oC for 4-8 min using cane bagasse with moisture contents in the range 16-100 wt% (dry basis). Increased moisture contents not only had a positive influence in recovery of main cane biomass components but also resulted in better substrates for enzymatic hydrolysis. As a result, drying is not required for optimal pretreatment and enzymatic hydrolysis of sugarcane bagasse, which can be processed into second generation ethanol immediately after crushing and hot water washing.

Induction Motors Vibration Monitoring Using a Biaxial Optical Fiber Accelerometer

In this paper, the implementation, characterization, calibration, and testing of a biaxial optical fiber accelerometer for vibration monitoring in three-phase induction motors is presented. The optical sensor uses fiber Bragg gratings to measure the displacement of an inertial mass relatively to a support base. The sensor characterization was measured through the impact hammer, allowing the determination of the natural frequencies in both sensitive directions, the values of 747.5 Hz and 757.5 Hz were estimated for the x-axis and the y-axis, respectively. For calibration, an electromagnetic exciter was used to introduce a controlled harmonic excitation at different frequencies, with this analysis, a high SNR was observed, on average over 30 dB for both sensitive directions, and a sensitivity of 100 pm × g-1 was obtained, up to one third of the natural frequency, in each direction. The tests were developed with the main aim of the analysis in induction motors based in vibration monitoring, the analysis can help to prevent wear in motors, increasing its efficiency, and lowering maintenance costs. The optical accelerometer measurements were compared with the ones from a capacitive sensor, during regular operation and with a broken rotor bar operating with 75% and 100% load. The performed tests with the optical sensor allowed to successfully analyze the frequency components, and its changes, for the regular and damage operation.

Síntese do Eval- g -norbixina: Aplicação como um Pigmento em Polímeros

The contamination by heavy metals present in polymer additives and pigments, is a serious health risks. Thus new methods have been implemented to the use of organic and biodegradable pigments. In this work, a technique was developed by grafting of norbixin in poly (ethylene-co-vinyl alcohol) for use as a pigment on polymer materials. From the results obtained by HPLC, it was observed that the alkaline extraction led the hydrolysis of bixin into norbixin. The analysis by FT-IR and DSC have identified the EVAL and the graft of norbixin. This technique showed to be an easy alternative, viable and attractive for the production of new pigments compared to traditionally used techniques described in the literature.

Improved Reactivity in the Ring-Opening Polymerization of ε-Caprolactone with a Trinuclear Titanium(IV) Oxochloroneopentoxide as Initiator

B Empirical formula C45H99ClO10Ti3·C7H8 Formula weight / (g mol -1 ) 1071.52 Temperature / K 100(2) Crystal system monoclinic Space group Pn (No.7) a / Å 15.2819(9) b / Å 13.4787(8) c / Å 15.4311(10)  / degree 97.214(2) V / Å3 3153.3(3) Z 2 μ / mm -1 0.460 θmax 25.5 Reflections collected 113847 Independent reflections 11747 Rint 0.082 Reflections with I > 2I 11571 R1 (I > 2σI) a 0.038 wR2 (I > 2σI) a 0.099 R1 all data a 0.039 wR2 all data a 0.100 Goodness-of-fit on F 2 1.049 Largest diff. peak and hole / eÅ -3 0.64, 0.31