Powering Systems From Ambient Energy Sources

Ambient intelligence and the Internet of Things will require flexible and energy efficient hardware platforms to implement the long-term deployed wireless devices that form the physical substrate for these emerging cyberphysical systems. Energy harvesting from environmental sources such as light and mechanical vibration can extend battery life for devices as long as efficient power management circuits are available. Self-timed circuits, power-on resets, integrated switched-capacitor DC/DC converters and adaptively-biased linear regulators are complementary circuit techniques that can reduce cost and power consumption for microwatt energy harvesting and energy scalable systems. Low power and low voltage analog and digital circuits for sampling, digitizing, and processing external signals are essential for powering systems from ambient energy sources. This talk presents an overview of these topics and describes how exploiting the relationship between system requirements, circuits, and environmental energy sources can enable the emergence of the Internet of Things

High bandwidth interchip communication for regular networks dc by Rajeevan Amirtharajah.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (leaves 48-49).M.Eng

Critical speeds and unbalance response of cantilever-sleeve rotors using finite elements with efficient higher order basis functions

Design of industrial rotor-bearing systems requires an understanding of their dynamic behavior, which involves the determination of their critical speeds and unbalance response. Dynamic behavior of simple rotor systems can be studied using analytical techniques. However, for complex rotor systems it is necessary to use approximate techniques. The finite element method is one such approximate technique and has been in use as a computational method for solving these problems. In most cases finite element method requires a fine discretization of the rotor model and this leads to setting up and solving a large number of simultaneous and coupled linear differential equations for the unknown displacements. With such large systems the calculation becomes very time consuming, which may not be economically feasible. The prime objective of the present investigation is to develop an efficient and economical technique for the determination of the critical speeds and the unbalance response of complex rotorbearing systems such as cantilever-sleeve rotor. The technique is based on higher order finite elements. By using this technique the size of system equations can be significantly reduced without affecting the dynamic characteristics of the system. The technique also incorporates all the natural and essential boundary conditions right in the basis functions at element formulation. Thus, this element adequately represents all the physical situations involved in any combination of displacement, rotation, bending moment and shearing force boundary conditions. The dynamic behavior of a cantilever-sleeve rotor with a disk at the end is studied using such higher order finite elements. More accurate results are obtained using a coarse mesh that has increased number of degrees of freedom. Further no errors are introduced-during post processing for stresses, strains, etc

An Evaluation of the Gerangamete Catchment Management Plan Using the Safe Minimum Standard

In this study an evaluation of the catchment management plan for the Gerangamete catchment is undertaken. This catchment suffers from dryland salinity which is a result of current landuse practices, and can only be solved by changing those practices. Current methods of land use evaluation have been criticised for their inflexibility and lack of attention to costs (both private and social) associated with particular land use activities. These deficiencies can limit the usefulness of land evaluation procedures for defining land capability and suitability for farm and regional land use planning for salinity control. In this study a method is outlined, which is based on incorporating deterministic spreadsheet modelling and risk analysis using simulation modelling which overcomes some of these deficiencies. The technique integrates biophysical and economic data in a measure which can be readily computed, updated and communicated to land managers

Life Cycle Aware Computing: Reusing Silicon Technology

Despite the high costs associated with processor manufacturing, the typical chip is used for only a fraction of its expected lifetime. Reusing processors would create a food chain of electronic devices that amortizes the energy required to build chips over several computing generations

MEMS electrostatic micropower generator for low frequency operation

Accepted versio

Mems inertial power generators for biomedical applications

Accepted versio

Impact of sludge floc size and water composition on dewaterability

In order to observe the impact of different water compositions on sludge dewaterability, assessments of floc sizes using a particle size analyzer and of sludge dewaterability based on the capillary suction time (CST) test were carried out. Synthetic raw water had small floc sizes, and synthetic domestic wastewater had both larger median floc sizes and a better correlation between sludge dewaterability and median floc sizes. The floc size distribution results showed that synthetic raw water is associated with a narrow particle size distribution. In comparison, synthetic domestic wastewater produced a wider distribution. However, the CST values were similar for both waters. Compared to synthetic wastewater, natural wastewater had the largest distribution with generally larger particle sizes