Losses and forces due to eddy currents in a magnetically non-linear conductive half space

A simple soft magnetically non-linear moving conductor model (“iron”) as “half-space” is presented under the inducing effect of a sinusoidal distributed current loading at different current amplitudes, covering the low to very high saturation level of 1–4 T. Eddy current losses, penetration depth of field and tangential braking and normal attractive forces are compared with the results for a linear conductor with constant saturation (relative permeability 100) for a velocity range, described by magnetic Reynolds numbers 1–300. Eddy current losses and the braking force are bigger for the non-linear case (typically 160–200%) and the penetration depth is bigger by 200–400%. The attractive force is smaller, first due to field compression at higher velocity, second due to the increased saturation level, which gives lower relative permeability values than the assumed constant value of 100 in the linear case. For a rough estimate of either eddy current effects in eddy current brakes and linear induction motors with massive secondary or of eddy current losses in electrical machines and apparatus often a constant saturation is assumed. The here presented results allow a preliminary correction due to the non-linear conductor effect, before a detailed non-linear numerical analysis of the investigated geometry is done.     

A multi-purpose Schrödinger-Poisson Solver for TCAD applications

We present the Vienna Schrödinger-Poisson Solver (VSP), a multi-purpose quantum mechanical solver for investigations on nano-scaled device structures. VSP includes a quantum mechanical solver for closed as well as open boundary problems on fairly arbitrary one-dimensional cross sections within the effective mass framework. For investigations on novel gate dielectrics VSP holds models for bulk and interface trap charges, and direct and trap assisted tunneling. Hetero-structured semiconductor devices, like resonant tunneling diodes (RTD), can be treated within the closed boundary model for quick estimation of resonant energy levels. The open boundary model allows evaluation of current voltage characteristics.     

Effects of nickel foam dimensions on catalytic activity of supported Co–Mn–B nanocomposites for hydrogen generation from stabilized borohydride solutions

In the present work, the catalytic activity of electrodeposited Co–Mn–B nanocomposites towards controllable hydrolysis of sodium borohydride was studied. Deposition was performed on two types of Ni-foam (RECEMAT Int.) with different pore size, specific surface area and thickness. Higher deposit loading, as well as bigger real surface area, was obtained with foam samples possessing bigger pore size. The catalyst deposited on bigger pore foam promoted hydrogen generation with higher rates than the other one when contacted with a base-stabilized NaBH₄ solution. The same activation energy value, however, was determined for both supported catalysts. On the base of the obtained results, it may be concluded that the geometric factor plays predominant role for the catalytic activity of studied catalysts.     

Frequency-Offset PLL for Synchronous Optical Sampling of OTDM Signals

We demonstrate a novel synchronization scheme for optical sampling which is based on a nonstandard phase-locked loop (PLL). Phase comparison is performed at a 10-GHz optical time-division-multiplexing (OTDM) base rate, thus avoiding ultrafast detectors and electronics. The employed frequency-offset PLL allows synchronous sampling of OTDM signals (or any other signals with bit rates given by integer multiples of the base rate), which would be impossible using a standard PLL. This provides a higher degree of flexibility for problem-specific sweeping than asynchronous sampling     

在线检测与分析 快速发现不可见的电学缺陷

在Fab里，在经过特别设计的短流程测试晶圆上进行的快速电学测试和自动FIB／SEM缺陷分析可以将不可见缺陷探测与分析的时间降低一个数量级，并且对不同的设计参数非常敏感，因而有足够的样本来做重要的统计评估。     

Technological change as a trade-off between social construction and technological paradigms

The theory of social construction of technology (SCOT) and the theory of technological paradigms (TTP) are normally regarded as competing or even incompatible perspectives on technological change. In this paper, we show how and when the perspectives are complementary by comparing how the theories conceptualise technology development, understand stakeholders, and determine driving forces for technological change. When stakeholders have different relations to the innovation process, and when the outcome of the innovation process is open, we argue that the two theories could be complementary tools for analysing the process. When using SCOT and TTP as complementary analytical tools, it becomes easier to understand and design innovation processes in which different stakeholders are attached to roles where they are able to contribute in the most productive ways.     

High Definition Digital Fabrication of Active Organic Devices by Molecular Jet Printing

We introduce a high resolution molecular jet (MoJet) printing technique for vacuum deposition of evaporated thin films and apply it to fabrication of 30 μm pixelated (800 ppi) molecular organic light emitting devices (OLEDs) based on aluminum tris(8‐hydroxyquinoline) (Alq₃) and fabrication of narrow channel (15 μm) organic field effect transistors (OFETs) with pentacene channel and silver contacts. Patterned printing of both organic and metal films is demonstrated, with the operating properties of MoJet‐printed OLEDs and OFETs shown to be comparable to the performance of devices fabricated by conventional evaporative deposition through a metal stencil. We show that the MoJet printing technique is reconfigurable for digital fabrication of arbitrary patterns with multiple material sets and high print accuracy (of better than 5 μm), and scalable to fabrication on large area substrates. Analogous to the concept of “drop‐on‐demand” in Inkjet printing technology, MoJet printing is a “flux‐on‐demand” process and we show it capable of fabricating multi‐layer stacked film structures, as needed for engineered organic devices.     

Oberflächenwellen‐Strukturen in Cu‐Damaszentechnologie

Application of the Copper Damascene Technology to Surface Acoustic Wave Structures A novel fabrication technology for power SAW devices with embedded interdigital transducers of a copper thin film system (copper damascene technology) is described. Such SAW structures have a significantly higher power durability and lifetime compared to usual Al‐based transducers. These properties denote that they become attractive for new applications where high SAW amplitudes and a flat surface of the device are required for these applications.     

Indirect measuring of crack growth by means of a key-curve-method in pre-cracked Charpy specimens made of nodular cast iron

The determination of dynamic crack resistance curves from single specimen fracture tests requires information about the crack advance during the experiment. Here, attention is focused on crack resistance curves for nodular cast iron based on experimental data from instrumented Charpy tests. In order to estimate the actual crack length a key curve method (KCM) is employed. On the other hand, the Charpy impact tests were realized numerically using finite element calculations in conjunction with a continuum damage model (CDM) to simulate ductile crack growth. The parameters of the CDM model were determined from the experimental data of single specimen fracture tests. Equivalence between the experimental and the numerical realization of a fracture test was ensured by validating the predictions of the numerical simulations by means of low blow fracture tests. Comparison between the crack advance predicted by the numerical simulations and the results obtained using the proposed KCM shows a sufficiently well agreement with the actual crack length. Furthermore, crack resistance curves obtained from single specimen tests using either standard estimation schemes in conjunction with the KCM or numerical simulations are compared with the predictions based on low blow fracture tests.     

Compiler optimizations for processors with SIMD instructions

To achieve maximum efficiency, modern embedded processors for media applications exploit single instruction multiple data (SIMD) instructions. SIMD instructions provide a form of vectorization where a large machine word is viewed as a vector of subwords and the same operation is performed on all subwords in parallel. Systematic usage of SIMD instructions can significantly improve program performance. With C becoming the dominant language for programming embedded devices, there is a clear need for C compilers that use SIMD instructions whenever appropriate. However, SIMD instructions typically require each memory access to be aligned with the instruction's data access size. Therefore an important problem in designing the compiler is to determine whether a C pointer is aligned, i.e. whether it refers to the beginning of a machine word. In this paper, we describe our SIMD generation algorithm and present an analysis method which determines the alignment of pointers at compile time. The alignment information is used to reduce the number of dynamic alignment checks and the overhead incurred by them. Our method uses an interprocedural analysis which propagates pointer alignment information in function bodies and through function calls. The effectiveness of our method is supported by experimental results which show that in typical programs the alignments of about 50% of the pointers can be statically determined. Copyright © 2006 John Wiley & Sons, Ltd.