Oxygen Ion Drift‐Induced Complementary Resistive Switching in Homo TiOx/TiOy/TiOx and Hetero TiOx/TiON/TiOx Triple Multilayer Frameworks

Developing a means by which to compete with commonly used Si‐based memory devices represents an important challenge for the realization of future three‐dimensionally stacked crossbar‐array memory devices with multifunctionality. Therefore, oxide‐based resistance switching memory (ReRAM), with its associated phenomena of oxygen ion drifts under a bias, is becoming increasingly important for use in nanoscalable crossbar arrays with an ideal memory cell size due to its simple metal–insulator–metal structure and low switching current of 10–100 μA. However, in a crossbar array geometry, one single memory element defined by the cross‐point of word and bit lines is highly susceptible to unintended leakage current due to parasitic paths around neighboring cells when no selective devices such as diodes or transistors are used. Therefore, the effective complementary resistive switching (CRS) features in all Ti‐oxide‐based triple layered homo Pt/TiO_x/TiO_y/TiO_x/Pt and hetero Pt/TiO_x/TiON/TiO_x/Pt geometries as alternative resistive switching matrices are reported. The possible resistive switching nature of the novel triple matrices is also discussed together with their electrical and structural properties. The ability to eliminate both an external resistor for efficient CRS operation and a metallic Pt middle electrode for further cost‐effective scalability will accelerate progress toward the realization of cross‐bar ReRAM in this framework.     

Preparation of chelating fabrics by radiation‐induced grafting of itaconic acid and acrylonitrile onto polypropylene nonwoven fabrics and subsequent amination of graft copolymer

A mixture of acrylonitrile (AN) and itaconic acid (IA) was cografted onto polypropylene (PP) nonwoven fabrics by preirradiation method. The effects of graft polymerization conditions such as temperature, reaction time, Mohr's salt concentration, solvent mixture ratio, and comonomer composition on the total grafting yield were investigated. The addition of AN as a comonomer increased the amount of IA that reacted with PP fabrics. An increase in the temperature from 40 to 60°C increased the grafting rate, but the final grafting yield decreased at high temperature. The addition of 0.01 wt % Mohr's salt to the reaction medium leaded to a sharp increase of grafting yield. The accelerative effect of solvent medium on the grating yield was higher in dimethylformamide (DMF) and methanol mixtures, when compared with DMF or methanol. Chelating fabrics was synthesized by subsequent amination of grafted fabric with ethylene diamine (EDA) and phenylhydrazine (PH). The conversion yield reached maximum value at about 90% for 80% PP‐g‐AN‐IA fabrics at 90°C. At same amination conditions, the conversion yield is higher when PP‐g‐AN‐IA fabrics react with EDA compared with PH. FT‐IR data indicate that amine groups were introduced onto PP‐g‐AN‐IA fabric through amide linkage between grafted AN or IA and EDA or PH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effects of Monascus-fermented grain extracts on plasma antioxidant status and tissue levels of ubiquinones and α-tocopherol in hyperlipidemic rats

We investigated the effects of Monascus-fermented mixed grain extracts (MFGEs) enriched with bioactive mevinolins (natural statins) and coenzyme Qs (CoQ₉ + CoQ₁₀) on the blood lipids, antioxidant status, and tissue levels of CoQs and α-tocopherol (α-Toc) in hyperlipidemic rats. The oral administration of MFGEs (300 mg/kg body weight per day) for 8 weeks resulted in a significant decrease in blood levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio compared to the control and lovastatin supplement group of a dosage of 20 mg/kg per day (p < 0.05). Furthermore, a significant increase in the ratios of α-Toc/LDL-C and CoQs/LDL-C in plasma and tissues and improvement in plasma antioxidant status as measured by TBARS and TRAP were observed in hypercholesterolemic rats (p < 0.05). Regarding the effects of MFGEs on antioxidant levels of plasma and tissues, there were significant increases in the levels of α-Toc (p < 0.05) and CoQs (p < 0.01) after the 8-week MFGEs treatment. These data indicate that MFGEs supplementation not only decreases blood lipids and lipid peroxidation but also increases levels of antioxidants such as α-Toc and CoQs and may improve plasma antioxidant status as well as a hypolipidemic effect.     

Image-rejection receiver using on-chip active notch filters for 2.4-GHz band wireless communication applications

This paper presents the design and experimental results of image-rejection (IR) receiver front-end for 2.4-GHz band applications. The proposed IR-receiver front-end integrates a third-order active notch filter into each of conventional cascode low noise amplifier and down-conversion mixer to achieve high image-rejection ratio (IRR). The image signal is suppressed and the wanted signal is maximized due to series and parallel resonator effects of the notch filter, respectively. Consequently, the proposed IR-receiver front-end implemented in a standard 0.18 μm CMOS technology has the power gain of 21.5 dB, the noise figure of 3.5 dB, the input third order intermodulation product of ?15 dBm and the IRR of 56 dB. The IR-receiver front-end dissipates a total of 5.5 mA from supply voltage of 1.8 V.     

A High‐Gain Microstrip Patch Array Antenna Using a Superstrate Layer

A dielectric superstrate layer above a microstrip patch antenna has remarkable effects on its gain and resonant characteristics. This paper experimentally investigates the effect of a superstrate layer for high gain on microstrip patch antennas. We measured the gain of antennas with and without a superstrate and found that the gain of a single patch with a superstrate was enhanced by about 4 dBi over the one without a superstrate at 12 GHz. The impedance bandwidths of a single patch with and without a superstrate for VSWR < 2 were above 11%. The designed 2×8 array antenna using a superstrate had a high gain of over 22.5 dB and a wide impedance bandwidth of over 17%.     

Multicomponent batch distillation with distillate receiver

Based on the assumption of adiabatic equilibrium stages, a rigorous calculation procedure applicable to a multicomponent batch distillation with a distillate receiver under total reflux condition was developed. Provided that the operating conditions including the desired product purity of the most volatile component in the receiver are specified, the proposed model estimates the volume of the distillate receiver, changes in compositions in the receiver and still, concentration profiles of the column, and the batch time required to complete the separation. In order to test the validity of the proposed model, experimental data for the separation of acetone-methanol-2-propanol mixture using a 10 cm I.D. column having six theoretical stages were compared with the simulation results for the two cases when the distillate receiver is initially empty and initially full.     

Simultaneous Burst and Burst Control Packet Transmission Protocol for Optical Burst Switching Ring Networks

In this letter, we design a collision resolution protocol for optical burst switching ring networks to avoid burst collision. We define the offset time condition for no burst transmission collision and manage the free time list of nodes for no burst reception collision. In order to improve the throughput, we use a fiber delay line, void‐filling, and void‐compression. This protocol does not require any additional procedures for bandwidth reservation such as centralized assignment of bandwidth, lightpath setup of WDM ring networks, or token capturing for the burst transmission. The simulation results show that the proposed protocol can achieve high throughput while saving 70% of wavelengths when compared to round robin with random selection, round robin with persistent, and round robin with non‐persistent with only destination delay.     

Narrow passband high-temperature superconducting filters of highly compact sizes for personal communication service applications

A novel highly compact high-temperature superconducting filter based on spiral lumped elements was demonstrated for personal communication system applications. The filter consists of eight-pole microstrip resonators enclosed in a substrate 0.5 /spl times/ 5 /spl times/ 32 mm. The filter was designed to have a bandwidth of 17 MHz and a center frequency of 1760 MHz. A low insertion loss of 0.4 dB in the passband with an out-of-band rejection loss of about -70 dB was observed at 65 K. Measured characteristics of the filter showed good agreement with simulated responses.     

An RFID Tag Using a Planar Inverted‐F Antenna Capable of Being Stuck to Metallic Objects

This letter presents the design for a low‐profile planar inverted‐F antenna (PIFA) that can be stuck to metallic objects to create a passive radio frequency identification (RFID) tag in the UHF band. The designed PIFA, which uses a dielectric substrate for the antenna, consists of a U‐slot patch for size reduction, several shorting pins, and a coplanar waveguide feeding structure to easily integrate with an RFID chip. The impedance bandwidth and maximum gain of the tag antenna are about 0.3% at 914 MHz for a voltage standing wave ratio (VSWR) of less than 2 and 3.6 dBi, respectively. The maximum read range is about 4.5 m as long as the tag antenna is on a metallic object.     

Design of wideband RFID tag antenna for metallic surfaces

A low-cost wideband antenna for radio frequency identification (RFID) tags mountable on metallic surfaces is presented. A novel proximity-coupled feed structure, in which the direction of the microstrip feedline is orthogonal to that of the resonant length of the radiating patch, is explored to perform simple and wideband impedance matching between an antenna and a tag chip without any additional matching networks. The proposed design is verified by simulation and measurement, which show good agreement.