Physical,Chemical, and Biological Properties of Chitosan-Coated Alginate Microparticles Loaded with Porcine Interleukin-1β: A Potential Protein Adjuvant Delivery System

We previously developed chicken interleukin-1β (IL-1β) mutants as single-dose adjuvants that induce protective immunity when co-administered with an avian vaccine. However, livestock such as pigs may require a vaccine adjuvant delivery system that provides long-lasting protection to reduce the need for successive booster doses. Therefore, we developed chitosan-coated alginate microparticles as a carrier for bovine serum albumin (BSA) or porcine IL-1β (pIL-1β) and assessed their physical, chemical, and biological properties. Electrospraying of the BSA-loaded alginate microparticles (BSA/ALG MPs) resulted in an encapsulation efficiency of 50%, and those MPs were then coated with chitosan (BSA/ALG/CHI MPs). Optical and scanning electron microscopy, zeta potential analysis, and Fourier transform infrared spectroscopy were used to characterize these MPs. The BSA encapsulation parameters were applied to ALG/CHI MPs loaded with pIL-1β, which were not cytotoxic to porcine fibroblasts but had enhanced bio-activity over unencapsulated pIL-1β. The chitosan layer of the BSA/ALG/CHI MPs prevented burst release and facilitated sustained release of pIL-1β for at least 28 days. In conclusion, BSA/ALG/CHI MPs prepared as a carrier for pIL-1β may be used as an adjuvant for the formulation of pig vaccines.     

Scene-Change Aware Dynamic Bandwidth Allocation for Real-Time VBR Video Transmission Over IEEE 802.15.3 Wireless Home Networks

IEEE 802.15.3, an emerging wireless technology, was designed to provide high-quality multimedia services at home. Dynamic bandwidth allocation for a multimedia connection should be considered in order to achieve higher channel utilization, less buffer and less delay, especially for variable bit rate (VBR) multimedia connections. For real-time VBR videos, the bandwidth requirement should be predicted adaptively for effective channel-time requests. Previously, the adaptive least-mean square (LMS) algorithm with fixed step size was applied to predict channel time requirements due to its simplicity and relatively good performance. However, the performance might degrade when scene changes occurred. In this paper, we modify the variable step-size LMS algorithm and apply it as our predictor (VSSNLMS) so that the prediction errors on scene changes can be effectively reduced. Using the prediction results of VSSNLMS, we propose a dynamic bandwidth-allocation scheme that is scene-change aware and can guarantee the delay bound of real-time VBR videos. Simulation results show that the VSSNLMS predictor is superior to previous LMS-type predictors in performance, and the proposed scheme has better performance in channel utilization, buffer usage, and packet loss     

An improved approach to find membership functions and multiple minimum supports in fuzzy data mining

Fuzzy mining approaches have recently been discussed for deriving fuzzy knowledge. Since items may have their own characteristics, different minimum supports and membership functions may be specified for different items. In the past, we proposed a genetic-fuzzy data-mining algorithm for extracting minimum supports and membership functions for items from quantitative transactions. In that paper, minimum supports and membership functions of all items are encoded in a chromosome such that it may be not easy to converge. In this paper, an enhanced approach is proposed, which processes the items in a divide-and-conquer strategy. The approach is called divide-and-conquer genetic-fuzzy mining algorithm for items with Multiple Minimum Supports (DGFMMS), and is designed for finding minimum supports, membership functions, and fuzzy association rules. Possible solutions are evaluated by their requirement satisfaction divided by their suitability of derived membership functions. The proposed GA framework maintains multiple populations, each for one item’s minimum support and membership functions. The final best minimum supports and membership functions in all the populations are then gathered together to be used for mining fuzzy association rules. Experimental results also show the effectiveness of the proposed approach.     

Design and implementation of a high‐efficiency LiFePO4 battery charger for electric vehicle applications

This letter studies and implements a high‐efficiency LiFePO₄ battery charger. The modular design can satisfy the requirements of series/parallel charging for electric vehicle applications. A CC‐CC‐CV charging scheme is also realized to meet the characteristics of LiFePO₄ battery stacks. A 2 kW laboratory prototype is built and tested. The experimental results are shown to verify the feasibility of the proposed scheme. Copyright © 2012 John Wiley & Sons, Ltd.     

Effects of three‐dimensional virtual reality and traditional training methods on mental workload and training performance

Industries will implement effective training programs to improve training performance, and an ideal training performance occurs under proper mental workload (MWL). Virtual reality (VR) has recently been widely utilized in training; however, only a few studies have investigated its effects on MWL and training performance simultaneously. The purpose of this study is to investigate the effects of VR training and traditional training methods, such as technical manuals (TM) and multimedia films (MF), on training performance and MWL. The results of the performance measurement show that VR training is considered the best training method compared to TM and MF, particularly in the case of complex tasks. The results of physiological measurements (GSR [galvanic skin response], LF% [low frequency], and LF/HF [high frequency] ratio) show a significant difference between reading TM and using computer (MF and VR), wherein the latter has a lower MWL. However, no significant difference in subjective MWL assessment (NASA‐TLX [task load index]) and HF% measurement is found.     

Proactive DAD: A Fast Address-Acquisition Strategy for Mobile IPv6 Networks

The increasing number of Wi-Fi-compatible mobile devices highlights various wireless access challenges, including the need for smooth hand offs between Internet attachment points in mobile IPv6 networks. To confirm address uniqueness in a new domain, mobile nodes must run duplicate address detection (DAD), which is a time-consuming process. The Proactive DAD approach uses topology information and layer-2 signals to predict the new network domains prior to or in parallel with layer-3 hand offs. Experimental results show that P-DAD can significantly reduce both hand-off latency and packet loss     

Dimethylsilylbis(1‐indenyl) zirconium dichloride/methylaluminoxane catalyst supported on nanosized silica for propylene polymerization

A dimethylsilylene‐bridged metallocene complex, (CH₃)₂Si(Ind)₂ZrCl₂, was supported on a nanosized silica particle, whose surface area was mostly external. The resulting catalyst was used to catalyze the polymerization of propylene to polypropylene. Under identical reaction conditions, a nanosized catalyst exhibited much better polymerization activity than a microsized catalyst. At the optimum polymerization temperature of 55°C, the former had 80% higher activity than the latter. In addition, the nanosized catalyst produced a polymer with a greater molecular weight, a narrower molecular weight distribution, and a higher melting point in comparison with the microsized catalyst. The nanosized catalyst's superiority was ascribed to the higher monomer concentration at its external active sites (which were free from internal diffusion resistance) and was also attributed to its much larger surface area. Electron microscopy results showed that the nanosized catalyst produced polymer particles of similar sizes and shapes, indicating that each nanosized catalyst particle had uniform polymerization activity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Resistance projection welding for TO-Can style package

The effects of the process parameters on the joint quality of TO-Can using resistance projection welding were investigated.A capacitor discharge stored energy welding machine was used for joining caps and headers both coated with nickel SPCC steel.The electrode materials used in this study were brass and W-Cu alloy.Experimen-tal results indicated that the peak current of the W-Cu electrode was higher than that of the brass electrode,irrespective of the operating pressure variation.Increased operating pressu...     

Ultrasonic Spray Pyrolysis for Synthesis of Spherical Zirconia Particles

This paper presents new findings on ultrasonic spray pyrolysis of zirconium hydroxyl acetate precursor drops whose sizes were precisely measured using laser light diffraction technique. Precursor concentration plays a predominant role in determination of product particle size. At 0.01 wt% precursor concentration, conventional spray pyrolysis at 750°C using precursor drops 5–8 μm in diameter, generated by an ultrasonic nebulizer at 2.66 MHz, yielded uniform spherical yttria-stabilized zirconia (YSZ) particles 73 nm in diameter measured by scanning electron microscopy. The YSZ particle diameters were much smaller than those predicted by the one-particle-per-drop mechanism. Under similar reaction conditions, the high-throughput ultrasound-modulated two-fluid (UMTF) spray pyrolysis of larger precursor drops (28-μm peak diameter) also yielded spherical dense particles; they were significantly smaller in size than those produced by the low-throughput conventional ultrasonic spray pyrolysis of smaller drops (6.8-μm peak diameter).