300 publications from this institution
Cellulose nanofibers (CNFs) were isolated from lettuce peel using specific chemical treatments, i.e., NaOH alkali solution treatment, NaClO 2 bleaching and sulfuric acid hydrolysis.Both cellulose and cellulose nanofibers were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD).The morphological features and particle size distribution of cellulose and nanostructures were explored using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and a Malvern laser particle size analyzer.The results showed that the particle diameters of the majority of nanofibrillated celluloses were in the range from 10 to 20 nm, and the length between 190 and 460 nm.The crystallinity index reached 41.57%, which increased by 117.3%, compared with the raw material.The crystalline lettuce peel nanofibers belong to cellulose type I.Moreover, the thermal degradation temperature of CNFs is 271.7 °C, which is 47.3 °C higher than that of the untreated peel.The CNFs obtained from these treatments can be used as additional reinforcement in biocomposites in composite manufacturing processes or in the food industry.
In this paper, a novel adaptive-gain sliding mode observer (SMO) is designed for sensorless control of permanent magnet linear synchronous motors (PMLSMs). By the proposed adaptive-gain algorithm, the gain can dynamically adapt to a changing operation condition of the PMLSMs and reach an appropriate value in finite time. Stability of the SMO is proved by using Lyapunov stability theory. Compared with the traditional SMO, the adaptive-gain SMO can improve the control precision, especially when the operation condition is not invariant. Simulation results are given to show the advantages of the proposed method.
Abstract The effect of high Cu2+ stress on fermentation performance and copper biosorption of Saccharomyces cerevisiae BH8 during wine fermentation was investigated in this paper. Under high Cu2+ stress, the cell growth and survival rate of yeast BH8 were inhibited. With different copper concentration, the effect on cell growth of yeast BH8 was different. What’s more, high Cu2+ stress could inhibit the fermentation property, alcohol production and reducing sugar utilization of yeast BH8 in Chardonnay grape must, but not significant. And the trend of the copper ion concentration falling down was consistent with the trend of yeast growth rising up, meanwhile the copper content was still much less than the initial concentration after fermentation. In addition, yeast BH8 showed a good fermenting property and copper removal ability under high Cu2+ stress. These results could provide certain reference and some new data for the wine industry to face the copper pollution risk.