Enhancement mode InP MISFET's with sulfide passivation andphoto-CVD grown P3N5 gate insulators

High performance enhancement mode InP MISFET's have been successfully fabricated by using the sulfide passivation for lower interface states and with photo-CVD grown P₃N₅ film used as gate insulator. The MISFET's thus fabricated exhibited exhibited pinch-off behavior with essentially no hysteresis. Furthermore the device showed a superior stability of drain current. Specifically under the gate bias of 2 V for 10⁴ seconds the room temperature drain current was shown to reduce from the initial value merely by 2.9% at the drain voltage of 4 V. The effective electron mobility and extrinsic transconductance are found to be about 2300 cm ²/V·s and 2.7 mS/mm, respectively. The capacitance-voltage characteristics of the sulfide passivated InP MIS diodes show little hysteresis and the minimum density of interface trap states as low as 2.6×10¹⁴/cm² eV has been attained     

Ultra-wideband (from DC to 110 GHz) CPW to CPS transition

A new ultra-wideband, low-loss and small-size coplanar waveguide (CPW) to coplanar strip (CPS) transition which can be used from DC to 110 GHz is presented. The proposed transition connects CPW with CPS by the reformed air-bridge. Two ground planes of CPW are tied at their ends by a line and the centre of the line is connected to the ground strip of CPS by another line. Owing to the symmetry of the proposed structure, the currents of two ground planes of CPW are combined with the same phase and transferred to the ground strip of CPS. With height of 3 μm, the signal line of CPW passes over two connecting lines and is connected to the signal strip of CPS. For the back-to-back transition structure, insertion loss <1 dB and return loss >15 dB are obtained from 0.5 to 110 GHz     

Preparation of core–shell type nanoparticles of diblock copolymers of poly(L‐lactide)/poly(ethylene glycol) and their characterization in vitro

Core–shell type nanoparticles of poly(L ‐lactide)/poly(ethylene glycol) (LE) diblock copolymer were prepared by a dialysis technique. Their size was confirmed as 40–70 nm using photon correlation spectroscopy. The ¹H‐NMR analysis confirmed the formation of core–shell type nanoparticles and drug loading. The particle size, drug loading, and drug release rate of the LE nanoparticles were slightly changed by the initial solvents that were used. The drug release behavior of LE core–shell type nanoparticles showed an initial burst during the first 12 h and then a sustained release until 100 h. The degradation behavior of LE block copolymer nanoparticles was divided into three phases: the initial rapid degradation phase, the stationary phase, and the rapid degradation phase until complete degradation. It was suggested that lidocaine release kinetics were predominantly governed by the diffusion mechanism in the initial burst phase and after that by both of the diffusion and degradation mechanisms. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2625–2634, 2002     

The prospects of non-volatile phase-change RAM

Phase-change read-and-write memory (PRAM) is a promising memory that can solve the problems of conventional memory—scalability, read/write speed, and reliability. We will review the opportunities and technical challenges of PRAM. The most important challenge of PRAM is the reduction of the writing current. Various approaches to reduce the writing current will be reviewed and the prospects of PRAM are discussed.     

Effect of trichloroethylene on the exploratory and locomotor activity of rats exposed during development

Trichloroethylene (TCE) is a common contaminant of underground water supplies. To examine the effect of TCE on the developing central nervous system, rats were exposed to TCE throughout gestation until 21 days postpartum via their dams' drinking water. TCE concentrations of 312 mg/l, 625 mg/l and 1250 mg/l were tested. Exploratory behavior was higher in 60- and 90-day old male rats which were exposed to any level of TCE. The effect of TCE-exposure on locomotor activity (running wheel) was also examined in 60-day old males (625 and 1250 ppm exposure groups). Locomotor activity was significantly higher in rats exposed to 1250 ppm TCE. These data suggest that TCE has long-term effects on behaviour.     

Spiking and Bursting in Josephson Junction

This brief reports spiking and bursting in numerical simulations of the resistive-capacitive-inductive shunted Josephson junction model. Regular spiking, intrinsic bursting, and fast spiking, which are usually seen in the mammalian neocortex, are observed in the junction dynamics under external dc bias. The junction voltage is amplitude and frequency modulated when forced by weaker sinusoidal forcing of frequency much lower than the junction resonant frequency. For stronger forcing, bursting is observed. The autonomous junction also shows bursting in the high inductive regime. Bifurcation scenarios of bursting are discussed for both autonomous and nonautonomous cases     

Computer modeling of the continuous annealing furnace

A computer program to calculate the strip temperature heated in the continuous annealing furnace was developed, using the zone method for radiative heat transfer analysis with the measured gas temperature in the furnace. Using theF _E Operator, the present study considered the effects of soot and transient species, in addition to the H₂O−CO₂ gas mixture on the gas radiative heat transfer. The predicted strip temperature distribution forF _E=1.05 represented well the measured data. The maximum difference in the heat flux transfered to the strip from the combustion gas forF _E=1.0 (without soot and transient species gas radiation) and 1.05 (with soot and transient species gas radiation) was about 15%. The present study also investigated the effects of line speed and thickness variations on the strip temperature, establishing the bases for the on-line computer model.     

Feature selection techniques and comparative studies for large-scale manufacturing processes

In order to efficiently and effectively control an overall process in the process industry, a few important parameters should be identified from high-dimensional, non-linear, and correlated data. Feature selection techniques can be employed to extract a subset of process parameters relevant to product quality. The performance of these techniques depends on the precision of the prediction model formulated to quantify the relationship between the process parameters and the quality characteristics. Although the neural network-based partial least squares (NNPLS) method has been proven to be effective in prediction models for the aforementioned industrial process data, feature selection techniques appropriate for NNPLS models have yet to appear. Here, several techniques for scoring the relevance of process parameters to product quality are proposed and validated by applying three datasets. These experiments show that the proposed techniques can discriminate relevant process parameters from irrelevant ones.     

Effects of potential and heat treatment on phase transition of alumina dielectric layer

The characteristics and growth behaviors of alumina dielectric layer formed by anodic oxidation were investigated. The aluminum oxide layer anodized at 400 V was predominantly amorphous alumina, but at the applied potentials more than 500 V, amorphous and crystalline γ-alumina were existed in anodic oxide layer and the ratio of γ-alumina increased with the increasing applied potential. During the heat treatment at 600^°C or higher temperature, amorphous alumina layer was transformed into the crystalline γ-alumina. The phase transition of anodic amorphous alumina into crystalline depends on anodic applied potentials and heat-treatment temperatures.