COVALENT IMMOBILIZATION OF BOVINE PHOSPHOLIPASE A2

Bovine phospholipase A ₂ (PPLA ₂ ) was immobilized onto controlled pore glass (CPG) beads using four different immobilization methods. PPLA ₂ was immobilized directly to CPG using glutaraldehyde without and with reduction by sodium borohydride (PP1 and PP2). Whey protein isolate was directly immobilized to CPG as a spacer followed by immobilization of PPLA ₂ without and with reduction (PP3 and PP4). Immobilized enzyme samples were characterized with respect to total amount of protein immobilized, activity with a fluorescent substrate and stability over 3 weeks. Among the methods, PP2 and PP4 showed the highest enzyme activity. All methods but PP2 showed a significant decrease in enzyme activity over 3 weeks. Enzyme immobilized by two methods (PP2 and PP4) were compared with soluble enzyme for the hydrolysis of egg phospholipids. Soluble and immobilized enzyme (PP4) resulted in similar free fatty acid values.     

CHARACTERIZATION OF TEXTURED WHEY PROTEIN PRODUCED AT VARYING PROTEIN CONCENTRATIONS

This research investigated the range of whey protein in a whey protein/starch mixture needed to produce an extrusion-textured whey product that contained a fibrous texture. It was determined that protein levels ranging from 48 to 64% were necessary for fiber formation. The functionality of textured whey protein (TWP) extrudates produced at three protein levels (48, 53 and 64%) from three different whey sources was characterized at three pH values (3, 5 and 7) and four temperatures (25, 50, 70 and 90C) with respect to solids lost (SL) and water-holding capacity (WHC). Significant differences were found in SL and WHC for each of the four variables. The consumer acceptability of beef patties extended by 50% TWP containing 48% protein was more acceptable to consumers than patties containing 50% textured vegetable protein, but scored lower than the 100% beef patties.

PRACTICAL APPLICATIONS

This study determined the maximum and minimum amount of whey protein in a whey protein/starch mixture required to produce an extrusion-textured whey product that contained a fibrous texture for use as a meat extender. There were no functional benefits of increasing the concentration of whey protein from 48%, which would not likely be practiced because whey protein is more costly than starch. Beef patties extended with 50% textured whey protein showed less cook loss, fat loss and diameter reduction than 100% beef patties while having sensory scores that were higher than patties extended with 50% textured vegetable protein.     

iSuppli：NAND闪存控制器营收下滑

iSuppli预计2007年全球NAND闪存控制器芯片营收下降11％，由2006年的4.36亿美元下降到3.86亿美元，这主要是由该控制器的平均销售价格（ASP）下降所至。2007年其价格下降到49美分，下降了30％。该控制器主要用于可移动闪存存储卡、USB闪存驱动器和固态硬盘（solidstate drives）等。     

A 960-Mb/s/pin interface for skew-tolerant bus using low jitter PLL

This paper describes an I/O scheme for use in a high-speed bus which eliminates setup and hold time requirements between clock and data by using an oversampling method. The I/O circuit uses a low jitter phase-locked loop (PLL) which suppresses the effect of supply noise. Measured results show peak-to-peak jitter of 150 ps and r.m.s. jitter of 15.7 ps on the clock line. Two experimental chips with 4-pin interface have been fabricated with a 0.6 μm CMOS technology, which exhibits the bandwidth of 960 Mb/s per pin     

Effect of nanoclay on properties of porous PVdF membranes

The main requirements for battery separators are high porosity which can serve pathways of lithium ion and space for gel electrolytes to impregnate in a membrane and mechanical strength to allow easy handling for battery assembly. Generally, it appears the trade-off relationship between the porosity and mechanical strength of the membrane. PVdF composite membranes containing nano-size clays were used to improve the mechanical strength of the membrane without affecting the membrane porosity. The composite me...     

Comparison and testing of power reserve control strategies for grid‐connected wind turbines

The stability of the electrical grid depends on enough generators being able to provide appropriate responses to sudden losses in generation capacity, increases in power demand or similar events. Within the United States, wind turbines largely do not provide such generation support, which has been acceptable because the penetration of wind energy into the grid has been relatively low. However, frequency support capabilities may need to be built into future generations of wind turbines to enable high penetration levels over approximately 20%. In this paper, we describe control strategies that can enable power reserve by leaving some wind energy uncaptured. Our focus is on the control strategies used by an operating turbine, where the turbine is asked to track a power reference signal supplied by the wind farm operator. We compare the strategies in terms of their control performance as well as their effects on the turbine itself, such as the possibility for increased loads on turbine components. It is assumed that the wind farm operator has access to the necessary grid information to generate the power reference provided to the turbine, and we do not simulate the electrical interaction between the turbine and the utility grid. Copyright © 2013 John Wiley & Sons, Ltd.     

Void defect detection in ball grid array X-ray images using a new blob filter

Ball grid arrays (BGAs) have been used in the production of electronic devices/assemblies because of their advantages of small size, high I/O port density, etc. However, BGA voids can degrade the performance of the board and cause failure. In this paper, a novel blob filter is proposed to automatically detect BGA voids presented in X-ray images. The proposed blob filter uses the local image gradient magnitude and thus is not influenced by image brightness, void position, or component interference. Different sized average box filters are employed to analyze the image in multi-scale, and as a result, the proposed blob filter is robust to void size. Experimental results show that the proposed method obtains void detection accuracy of up to 93.47% while maintaining a low false ratio. It outperforms another recent algorithm based on edge detection by 40.69% with respect to the average detection accuracy, and by 16.91% with respect to the average false ratio.