Fermentation of Monascus purpureus on Bacterial Cellulose-nata and the Color Stability of Monascus-nata Complex

Nata, a bacterial cellulose produced by Acetobacter aceti ssp. xylinum , was colored by means of fermentation with Monascus purpureus. Scanning electron microscopy (SEM) observations showed that the Monascus mycelium could grow through the cellulose network of nata. Rice powder as a major carbon source and monosodium glutamate (MSG) as a nitrogen source gave an appealing coloration after 12 d of fermentation at 30 °C. Compared to dyed nata, the color of the Monascus -nata complex had better resistance to washing, heat, freezing, acidification, and alkalization. A 66.1% decolorization was found under irradiation with 366 nm ultraviolet light after 36 h. The Monascus -nata complex has the potential to be a new vegetarian foodstuff.     

Lactic acid bacterial fermentation on the production of functional antioxidant herbal Anoectochilus formosanus Hayata

This study evaluated a novel use of the traditional Asian herb Anoectochilus formosanus. This plant is a traditional food item, generally used for the treatment of liver disorder, hepatitis, hypertension, diabetes, cardiovascular disorder, etc. In this study, the root, stem, and leaf of A. formosanus were used as substrates for lactic fermentation. The fermentation products were analyzed for their total antioxidant activity, reducing power, and scavenging effect on superoxide anion radicals and hydrogen peroxide. The pH of the fermentation medium reached its lowest value, 3.5, at the 35th hour of fermentation. Antioxidant activity of A. formosanus was found to be 61-78%. Lactobacillus longum-led fermentation exhibited the greatest reducing power with an average of 0.3. The products of fermentations utilizing the three plant parts as substrates exhibited a similar scavenging activity (27-30%) on free radicals. This study may suggest a novel use of lactic-fermenting A. formosanus in the production of functional food.     

Zernike moment and local distribution fitting fuzzy energy-based active contours for image segmentation

This paper presents a new region-based active contour model for extracting the object boundaries in an image, based on techniques of curve evolution. The proposed model introduces an energy functional that involves intensity distributions in local image regions and fuzzy membership functions. The local image intensity distribution information used to guide the motion of the contour, in the paper, is derived by Hueckel operator in the neighborhood of each image point. The parameters of Hueckel operator are estimated by a set of orthogonal Zernike moments before curve evolution. Meanwhile, the fuzzy membership functions are used to measure the association degree of each image pixel to the region outside and inside the contour. To minimize the energy functional, instead of solving the Euler–Lagrange equation of the underlying problem, the paper employs a direct method to compute the energy alterations. As a result, the model can deal with images with intensity inhomogeneity. In addition, the model effectively alleviates the sensitivity to contour initialization. Moreover, the model reduces computational cost, avoids problems associated with choosing time steps as well as allows fast convergence to the segmentation solutions. Experimental results on synthetic, real images and comparisons with other models show the desired performances of the proposed model.     

Fabrication of micro-electrodes by multi-EDM grinding process

In this study, a multi-EDM grinding process is adapted to fabricate micro-electrodes. Equipments such as a wire EDM machine and a traditional CNC-EDM machine are used for machining micro-electrodes. Rod electrodes of copper with diameter 3.0 mm were cut to be 0.15 mm on wire-EDM machine at first step. EDM grinding process was used to grind micro-electrodes to fine diameter bellow 20 μm on a CNC-EDM machine at second step. For EDM grinding, rotating mechanisms are mounted on both the WEDM machine and the CNC-EDM machine. A CCD camera is provided for viewing and for on-line dimensional controlling, when micro-electrodes were cutting. Fine electrodes could be processed to a smaller size using proposed two-steps EDM grinding process. Higher L/D ratio could be also achieved by this method. The processed fine electrodes can be used for drilling micro-holes, micro-deep holes, micro-milling, micro-punching, and manufacturing of micro-nozzles.     

A new switching surface sliding-mode speed control for inductionmotor drive systems

In this paper, a sliding-mode speed controller based on a new switching surface is proposed for induction motor systems. With this variable structure control switching surface, the exponential stability is guaranteed for the speed servo control and insensitivity to uncertainties and disturbances are obtained as well. Moreover, an adaptive variable structure speed control is studied to relax the need for the bound of disturbance in variable structure control. The insensitivity or robustness of the proposed method for general speed servo systems is maintained, and the dynamic performances are improved as well. Finally, the validity of proposed scheme is demonstrated by computer simulations and experimentations     

The effects of pH, salt, heating and freezing on the physical properties of bacterial cellulose—nata

Summary The effects of pH (2, 7 and 10), NaCl concentrations (0, 1, 3 and 5% w/w), and temperatures (−20, 25 and 100 °C) on the physical properties of nata, a bacteria cellulose produced by Acetobacter aceti ssp. xylinum , were evaluated in this study. The addition of NaCl was found to increase the hardness of nata but to decrease the water-holding capacity; however, no effect of NaCl on the hardness of nata was found when nata was acidified or alkalized. Compared to the texture properties of nata at 25 °C, freezing at −20 °C for 24 h gave a more elastic texture, but heating at 100 °C for 3 h had no significant effect on the textural properties. The results of this study indicated that acidification or alkalization was necessary to prepare salted nata products without increasing their hardness.     

Image encryption by multiple random grids

In this paper, we first give a formal definition to the visual cryptograms of n (?2) random grids (VCRG-n) for encrypting an image. Specifically, a set of VCRG-n with respect to image P consists of n random grids printed on transparencies such that only when the n transparencies are superimposed altogether can P be recognized by human vision (without any computing device), while any group of less than n transparencies obtains no information about P. Then, we design novel VCRG-n encryption schemes for binary, gray-level and color images, validate the correctness by formal proofs and demonstrate the feasibility by computer simulations. Our schemes do not require any extra pixel expansion neither any encoding basis matrix, which are necessary and inevitable in the approaches of conventional visual cryptography. These attractive advantages make our schemes more informative in theoretical interests and much applicable in practical applications.