Work Function Tunability of Refractory Metal Nitrides by Lanthanum or Aluminum Doping for Advanced CMOS Devices

A lanthanum (La)-doped HfN is investigated as an n-type metal gate electrode on SiO₂ with tunable work function. The variation of La concentration in (HfinfinLa_1-x)N_y modulates the gate work function from 4.6 to 3.9 eV and remains stable after high-temperature annealing (900degC to 1000degC), which makes it suitable for n-channel MOSFET application. An ultrathin high-fc dielectric layer was formed at the metal/SiO₂ interface due to the (HfinfinLa_1-x)N_y and SiO₂ interaction during annealing. This causes a slight reduction in the effective oxide thickness and improves the tunneling current of the gate dielectric by two to three orders. We also report the tunability of TaN with Al doping, which is suitable for a p-type metal gate work function. Based on our results, several dual-gate integration processes by incorporating lanthanum or aluminum into a refractory metal nitride for CMOS technology are proposed.     

High-Temperature Metallic Melts – Resistivity Intercomparison for Space Applications

Liquid state densities and electrical resistivities of pure copper and nickel as well as some of their binary alloys in the vicinity of the constantan mixing ratio (Cu53Ni47 at%) were measured by electromagnetic levitation and pulse-heating techniques. The experiments were performed as part of a joint project between the German Aerospace Center (DLR) and Graz University of Technology (TUG) with the main objective being to compare and support deeper understanding of different techniques for electrical resistivity measurements and their data. The manufacture of a levitation experiment similar to the setup at DLR is underway, which is scheduled for microgravity (μg) experiments onboard the ISS in 2010. As a first step, DLR performed measurements on a set of binary Cu–Ni-alloys (as well as two pure constituents), and independent experiments for constantan and the two pure metals were conducted at TUG. The results give promising agreement between the two techniques, show a reasonable overlap within the estimated uncertainties, and lead the way to more comparative measurements with newly developed materials.     

Investigation and Improvement of Transient Response of DVR at Medium Voltage Level

An area of interest for dynamic voltage restorer (DVR) research is the damping of transient oscillations initiated at the start and at the recovery instant from a voltage sag. Nonlinear loads, with harmonic currents close to the DVR filter resonance frequency, can also excite the resonance oscillations. To compensate voltage sags and dampen high-frequency oscillations simultaneously, an investigation of the transient response of DVR is first carried out. Possible control schemes and their effects on the oscillation attenuation are also studied. Such studied control schemes include the commonly used single voltage loop control, voltage feedback plus reference feedforward control, and double-loop control with an outer voltage loop and an inner current loop. Subsequently, an effective and simple resonance damping method is proposed by employing a closed-loop control with an embedded two-step Posicast controller. The proposed control methods have been extensively tested on a 10-kV DVR system. It is shown that the proposed damping methods improve both the transient and steady-state performance of the DVR.     

Geometry dependence of microstructure and microhardness for selective electron beam-melted Ti–6Al–4V parts

In an additive-manufactured metallic part, distinct and different microstructure and mechanical properties may exist in different areas due to differences in shape and location. Two parts, one with straight-finned structure and the other with curve-finned structure, were fabricated by the selective electron beam melting method using pre-alloyed Ti–6Al–4V ELI powder. Microstructural characterisation of these two parts that have varying fin thickness and shape was carried out to investigate the synthetical influence of 2D planar build geometry and in-fill hatching strategy on selective electron beam melting. It was found that the β interspacing is larger in the curve-finned structure, leading to a lower microhardness as compared to the straight-finned structure. It suggests a slower cooling rate in the curve-finned structure due to the differences in build geometry and in-fill hatching strategy.     

Highly Flexible Graphene Oxide Nanosuspension Liquid‐Based Microfluidic Tactile Sensor

A novel graphene oxide (GO) nanosuspension liquid‐based microfluidic tactile sensor is developed. It comprises a UV ozone‐bonded Ecoflex–polydimethylsiloxane microfluidic assembly filled with GO nanosuspension, which serves as the working fluid of the tactile sensor. This device is highly flexible and able to withstand numerous modes of deformation as well as distinguish various user‐applied mechanical forces it is subjected to, including pressing, stretching, and bending. This tactile sensor is also highly deformable and wearable, and capable of recognizing and differentiating distinct hand muscle‐induced motions, such as finger flexing and fist clenching. Moreover, subtle differences in the handgrip strength derived from the first clenching gesture can be identified based on the electrical response of our device. This work highlights the potential application of the GO nanosuspension liquid‐based flexible microfluidic tactile sensing platform as a wearable diagnostic and prognostic device for real‐time health monitoring. Also importantly, this work can further facilitate the exploration and potential realization of a functional liquid‐state device technology with superior mechanical flexibility and conformability.     

Attention Based Detection and Recognition of Hand Postures Against Complex Backgrounds

A system for the detection, segmentation and recognition of multi-class hand postures against complex natural backgrounds is presented. Visual attention, which is the cognitive process of selectively concentrating on a region of interest in the visual field, helps human to recognize objects in cluttered natural scenes. The proposed system utilizes a Bayesian model of visual attention to generate a saliency map, and to detect and identify the hand region. Feature based visual attention is implemented using a combination of high level (shape, texture) and low level (color) image features. The shape and texture features are extracted from a skin similarity map, using a computational model of the ventral stream of visual cortex. The skin similarity map, which represents the similarity of each pixel to the human skin color in HSI color space, enhanced the edges and shapes within the skin colored regions. The color features used are the discretized chrominance components in HSI, YCbCr color spaces, and the similarity to skin map. The hand postures are classified using the shape and texture features, with a support vector machines classifier. A new 10 class complex background hand posture dataset namely NUS hand posture dataset-II is developed for testing the proposed algorithm (40 subjects, different ethnicities, various hand sizes, 2750 hand postures and 2000 background images). The algorithm is tested for hand detection and hand posture recognition using 10 fold cross-validation. The experimental results show that the algorithm has a person independent performance, and is reliable against variations in hand sizes and complex backgrounds. The algorithm provided a recognition rate of 94.36 %. A comparison of the proposed algorithm with other existing methods evidences its better performance.     

Learning control in robotic systems

The concept of learning and training machines, and some early methodologies were introduced about two decades ago. Robotic systems, undoubtedly, can be developed to a more advanced and intelligent stage. The realization of the learning capability, analogous to the human learning and thinking process, is a desired primary function. A betterment process has been investigated in the literature for applications of learning control to robotic systems. The existing schemes are a type of one-step learning process. A neighboring (2m+1)-step learning control scheme for robotic systems is presented in this paper. For each process, a betterment algorithm which chooses a generalized momentum as an output function, is executed. Also, it is associated with a conceptual learning process by adding a self-teaching knowledge base for speeding up the convergence, so that the learning capability of the resulting robotic systems can be enhanced.     

Contactless Electrical Conductivity Measurement of Electromagnetically Levitated Metallic Melts

A facility for noninvasive measurements of the electrical conductivity of liquid metals above and below the melting temperature is presented. It combines the containerless positioning method of electromagnetic levitation with the contact-less technique of inductive conductivity measurement. Contrary to the conventional measurement method, the sample is freely suspended within the measuring field and, thus, has no exactly predefined shape. This made a new theoretical basis necessary with implications on the measurement and levitation fields. Furthermore, the problem of the mutual inductive interactions between the levitation and the measuring coils had to be solved.     

Global Synethetic Rubber Industrial Outlook

This paper is to compile and analyze the statistical data of synthetic rubber capacity and consumption to understand its impact of supply/demand on the global synthetic rubber market.Some forecasted consumption data were generated and published by the joint efforts of both IISRP(International Institute of Synthetic Rubber Producers)and IRSG(International Rubber Study group).The report also covers the observed industrial trends as well as some emerging issues in the synthetic rubber industry.