European Research into Sewer Sediments and Associated Pollutants and Processes

Research investigating all aspects of solids in sewer systems has been underway in Europe for nearly two decades. Due to the early development of European sewer systems, originally as part of the industrialization process more than 100 years ago, urbanization has caused the original sewer networks to become overloaded and unable to function efficiently. Operational problems of interest include loss of ability to convey (designed) flows and the performance of “overflows” to relieve the high flows discharging directly into rivers and other watercourses. Research has characterized the nature of the solids getting into sewer systems, how they behave in terms of transport, and some of the main aspects of their effects. It has been possible to demonstrate that much of the pollutants found in suspension during storms, and likely to be discharged from overflows, originate from the predominantly organic “near bed solids” which accumulate in systems during dry weather. New ideas for the way in which the sediments are transported and the importance of the transformation processes, are leading toward the development of a unified and integrated understanding of the way in which sewer solids behave and the associated biochemical transformation processes.     

MIPS32 M4K处理器内核SRAM接口应用

微控制器环境要求在尽可能小的封装里实现最多的通用I/O。在微控制器尺寸和成本的限制下,M4K内核内部不支持指令高速缓存(I- cache)或数据高速缓存(D-cache)的标准功能。但MIPS32 M4K内核所具有的一些特点使其非常适用于微控制器应用领域。这就涉及到本文重点讨论的一个内容——SRAM接口,这是MIPS32 M4K内核的一个标准功能。     

Isaak Named 2009 Computer Society President-Elect

The IEEE Computer Society recently elected James D. Isaak to serve as president-elect for 2009. In addition, new Board of Governors members and vice presidents also have been selected.     

Simulation of Fatigue Crack Propagation in Ductile Metals by Blunting and Re-sharpening

Laird and Smith [(1962). Philosophical Magazine 8, 847–857] proposed a plastic sliding-off mechanism for the stage II fatigue crack growth via striation formation. In their view, the fatigue crack extension results solely from the changing character of deformation at the crack tip during loading and unloading. In particular, the crack tip blunts during the loading stage and folds into a double notch during the unloading stage, resulting in striation formation. In order to verify Laird’s plastic blunting mechanism for ductile polycrystals as well as for ductile fcc single crystals, FE calculations were performed for a rectangular plate with an initially sharp crack under plane strain conditions. The plate was subjected to a fully reversed tension-to-pressure cyclic load perpendicular to the crack plane (Mode 1). In the single crystal case the crack propagation simulations were carried out for cracks with crack plane (001) for two different crack growth orientations [110] and [100]. No initial radius for the crack tip was assumed. The actual shape of the crack tip followed from an initially sharp crack by repeated remeshing. To model the constitutive behavior typical for polycrystalline ductile metals, J₂ hypo-elasto-plasticity model with Armstrong–Frederick kinematic hardening was used. To model the constitutive behavior typical for ductile fcc single crystals, a geometrically nonlinear version of Cailletaud’s model based on the multiplicative elasto-plastic decomposition of the deformation gradient was implemented into the FE program ABAQUS. For simplicity, only octahedral slip systems were considered. Using repeated remeshing for severely distorted elements at the advancing crack tip, deformation patterns in the sense of Laird’s mechanism for fatigue crack propagation with striation formation were obtained in the case of the polycrystal simulation as well as in the case of the single crystal simulation for [110] crack growth direction. The simulation for [100] crack growth direction with the same stress level as for [110] direction also yielded crack extension by progressive large deformations but without striation formation. The dependence of the fatigue striation formation on the crack growth direction as predicted by the simulation of crack propagation in single crystals is verified by the experimental results of Neumann [(1974). Acta Metallurgica 22, 1155–1165] on pure copper single crystals.     

Postcolonialism and education: negotiating a contested terrain

This paper sets the context for those that follow in this special issue of Pedagogy, Culture & Society. In so doing, it provides a brief overview of postcolonialism as theory, politics and practice. It considers postcolonialism's ambivalent reception amongst differing constituencies, a sign both of desire and danger, as Stuart Hall has put it. Criticisms of postcolonialism have come from both the left and the right and from indigenous scholars as well. In traversing the nature of postcolonialism, the paper considers the work, albeit briefly, of a number of major 'foundational' thinkers, namely Fanon, Said, Bhabha and Spivak. The need for a more liberatory rather than conciliatory postcolonialism is argued for, as is the need to integrate postcolonialism with an understanding of contemporary globalization. Postcolonial insights can help overcome the ahistoricity of much globalization theorizing and also its reification. Against this backdrop, the paper then provides a summative account of all of the contributions in this special issue, all of which demonstrate how new cultural practices and policy imperatives in education are linked to colonial and postcolonial formations.     

电气纵横制交换机:何去何从

为了满足服务提供商和供应商的要求,电气纵横制交换技术还能坚持多久?日益增长的网络要求需要协议、数据包和信元全方位的支持,其发展速度在几年前是无法想象的.全光交换技术也加入到竞争的行列.     

设计RF CMOS蓝牙收发器

使用CMOS RFIC设计2.4GHz蓝牙收发器需要在设计过程中的所有阶段对关键性能进行仔细的验证。这可以通过EDA软件的几个功能来实现,如提供晶片厂模型库,带有蓝牙测试信号的系统兼容性测试模板,还可以和测试仪器的链接,验证仿真数据和实际测量结果是否一致。     

Virtual Control Desks for Nuclear Power Plant Simulation: Improving Operator Training

Current nuclear power plant simulators employ interfaces that use multiple computer displays to represent a simplified control desk. To make the simulation more realistic and effective, a proposed approach replaces the displays with a virtual control desk that precisely mimics the original.     

The thrill of victory and the agony of defeat: Spontaneous expressions of medal winners of the 2004 Athens Olympic games.

Facial behaviors of medal winners of the judo competition at the 2004 Athens Olympic Games were coded with P. Ekman and W. V. Friesen's (1978) Facial Affect Coding System (FACS) and interpreted using their Emotion FACS dictionary. Winners' spontaneous expressions were captured immediately when they completed medal matches, when they received their medal from a dignitary, and when they posed on the podium. The 84 athletes who contributed expressions came from 35 countries. The findings strongly supported the notion that expressions occur in relation to emotionally evocative contexts in people of all cultures, that these expressions correspond to the facial expressions of emotion considered to be universal, that expressions provide information that can reliably differentiate the antecedent situations that produced them, and that expressions that occur without inhibition are different than those that occur in social and interactive settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)