Modelling of through silicon via and devices electromagnetic coupling

This paper is essentially composed of two parts for future synthesis. We developed 2D and 3D simulations, starting from a 0.35 μm standard CMOS technology, focusing on through silicon via or redistribution layer induced coupling; nMOSFET, pMOSFET, and the sensitive regions of the CMOS inverter are investigated. We also study stacked devices in 3D circuits, in the radiofrequency range, and propagation of electromagnetic waves along some interconnections with discontinuities. This study is performed in the time domain—a finite-difference time-domain method is applied to the analysis of some vias flanked by two striplines, all embedded in silicon. Electric and magnetic field distributions, transmission and reflexion parameters, and pulse propagations along a transverse via are presented.     

The fracture energy of metal fibre reinforced ceramic composites (MFCs)

A model is presented for prediction of the fracture energy of ceramic-matrix composites containing dispersed metallic fibres. It is assumed that the work of fracture comes entirely from pull-out and/or plastic deformation of fibres bridging the crack plane. Comparisons are presented between these predictions and experimental measurements made on a commercially-available composite material of this type, containing stainless steel (304) fibres in a matrix predominantly comprising alumina and alumino-silicate phases. Good agreement is observed, and it’s noted that there is scope for the fracture energy levels to be high (∼20 kJ m⁻²). Higher toughness levels are both predicted and observed for coarser fibres, up to a practical limit for the fibre diameter of the order of 0.5 mm. Other deductions are also made concerning strategies for optimisation of the toughness of this type of material.     

软测量的工程化设计

将软测量应用到工业生产之前必须解决其工程化设计的问题.为此,在软测量技术理论研究和应用经验的基础上,对软测量工程化设计中应解决的关键问题和解决方法进行了研究.软测量的工程化设计包括机理分析、辅助变量选择、数据采集和预处理、建立软测量模型、设计校正模块等步骤.其关键技术在于软测量过程的数据处理、模型的建立和校正.并以杭州龙山化工厂碳酸化塔中C02浓度软测量的工程化设计为例,对工程化设计中的一些关键问题处理进行介绍.实践表明,软测量的工程化设计在实际工业生产中具有很好的应用性和指导性,但也有待更进一步的研究.     

Nilsson's Power Model connecting speed and road trauma: Applicability by road type and alternative models for urban roads

Nilsson (1981) proposed power relationships connecting changes in traffic speeds with changes in road crashes at various levels of injury severity. Increases in fatal crashes are related to the 4^th power of the increase in mean speed, increases in serious casualty crashes (those involving death or serious injury) according to the 3^rd power, and increases in casualty crashes (those involving death or any injury) according to the 2^nd power. Increases in numbers of crash victims at cumulative levels of injury severity are related to the crash increases plus higher powers predicting the number of victims per crash. These relationships are frequently applied in OECD countries to estimate road trauma reductions resulting from expected speed reductions. The relationships were empirically derived based on speed changes resulting from a large number of rural speed limit changes in Sweden during 1967-1972. Nilsson (2004) noted that there had been very few urban speed limit changes studied to test his power model. This paper aims to test the assumption that the model is equally applicable in all road environments. It was found that the road environment is an important moderator of Nilsson's power model. While Nilsson's model appears satisfactory for rural highways and freeways, the model does not appear to be directly applicable to traffic speed changes on urban arterial roads. The evidence of monotonically increasing powers applicable to changes in road trauma at increasing injury severity levels with changes in mean speed is weak. The estimated power applicable to serious casualties on urban arterial roads was significantly less than that on rural highways, which was also significantly less than that on freeways. Alternative models linking the parameters of speed distributions with road trauma are reviewed and some conclusions reached for their use on urban roads instead of Nilsson's model. Further research is needed on the relationships between serious road trauma and urban speeds.     

Estimating using cost significant global cost models

Cost significant models have been suggested as one way of overcoming criticisms of the amount of detail contained within the traditional bill of quantities. Recent research into these models reveals a lack of formal rules for the selection of work packages to be used within the models, and a potential to overestimate the cost of projects. This paper presents a methodology for selecting work packages, and recommends a refinement to the technique that reduces the variability in estimates produced using cost significance. Estimates are produced using both the traditional method of producing cost significant models, and a refined global cost methodology. Both techniques are tested against unpriced bills to measure the difference in results, with significant improvements being achieved with the new technique.     

The visualization of knots and braids

We describe a new method for modelling braids and certain classes of knots and links, and how they may be visualized. The method uses generalized cylinders built around a bicubic spline centre line. We also show how multi-stranded, recursive, hawser laid ropes can be modelled using related techniques.     

Modelling of granulation by a two-stage auto-layering mechanism in continuous industrial drums

A mechanistic model for the granulation of particulate materials with a wide size distribution in a large-scale continuous drum is presented. It takes cognizance of the effect of relevant process variables: feed size distribution, moisture content, binders such as lime, residence time distribution, feed rate, etc. The model is based on the auto-layering mechanism of granule growth and incorporates a piecewise linear model for granulation kinetics. Laboratory scale tests on a batch drum are used to provide kinetic parameters. The size-dependent residence time distribution of agglomerating mass in the continuous drum is represented by a combination of mixed and plug flow regimes operating in parallel. The model is customized for a continuous drum in an iron ore fines sintering plant. The predicted granule size distributions are in good agreement with the plant data under widely varying operating conditions. The modelling framework provides scope for modifying the individual modules for drum residence time distribution or the granulation mechanism and growth kinetics.     

Critical review of models for H2-permeation through polymers with focus on the differential pressure method

To reduce loss of hydrogen in storage vessels with high energy-to-weight-ratio, new materials, especially polymers, have to be developed as barrier materials. Very established methods for characterization of barrier materials with permeation measurements are the time-lag and flow rate method along with the differential pressure method, which resembles the nature of hydrogen vessel systems very well. Long measurement durations are necessary to gain suitable measurement data for these evaluation methods, and often restrictive conditions have to be fullfilled. For these reasons, common models for hydrogen permeation through single-layer and multi-layer membranes, as well as models for hydrogen gas properties were collected and reviewed. Using current computer power together with these models can reduce measurement time for characterization of the barrier properties of materials, while additional information about the quality of the measurement results is obtained.     

IEA Mobility Model (MoMo) and its use in the ETP 2008

The IEA published “Energy Technology Perspectives” (ETP) in June 2008. That document reports on IEA scenarios for baseline and low-CO₂ alternative scenarios to 2050, across the energy economy. The study included creating scenarios for transport, using the IEA Mobility Model (MoMo). This paper reports on the transport-related ETP scenarios and describes the model used in the analysis. According to the ETP Baseline scenario, world transport energy use and CO₂ emissions will more than double by 2050. In the most challenging scenario, called “BLUE”, transport emissions are reduced by 70% in 2050 compared to their baseline level in that year (and about 25% below their 2005 levels). There are several versions of the BLUE scenario, but all involve: a 50% or greater improvement in LDV efficiency, 30–50% improvement in efficiency of other modes (e.g. trucks, ships and aircraft), 25% substitution of liquid fossil fuels by biofuels, and considerable penetration of electric and/or fuel-cell vehicles. In the second half of this paper, an overview of the MoMo model is provided. Details on the complete analysis are contained in the ETP 2008 document, available at www.iea.org. Details of the LDV fuel economy analysis are contained in a separate paper in this collection.     

A new one-phase material model for the numerical prediction of critical material flow conditions in thixoforging processes

Thixoforging allows one-step forming processes of near-net shape components having excellent mechanical properties. However, the high sensitivity of thixoforging regarding process conditions requires precise modelling and determination of process related parameters. At the same time, simple numerical design proves challenging because of the inaccuracy of existing one-phase material models regarding the shear thinning flow behaviour of semi solid metals. Consequently, this paper deals with the development of a new one-phase material model providing a more precise simulation of materials’ shear rate dependency. By using this model, simulations could be performed, which allowed the prediction of solidification and flow-related component defects.