THE DESIGN OF A POWER SYSTEM FOR A WIRELESS SENSOR NETWORK FOR LONG-TERM OPERATION

Wireless sensor networks (WSNs) have shown wide applicability to many fields including monitoring of environmental, civil, and industrial settings. WSNs however are resource constrained by many competing factors that span their hardware, software, and networking. One of the central resource constrains is the charge consumption of WSN nodes. With finite energy supplies, low charge consumption is needed to ensure long lifetimes and success of WSNs. This thesis details the design of a power system to support long-term operation of WSNs. The power system’s development occurs in parallel with a custom WSN from the Queen’s MEMS Lab (QML-WSN), with the goal of supporting a 1+ year lifetime without sacrificing functionality. The final power system design utilizes a TPS62740 DC-DC converter with AA alkaline batteries to efficiently supply the nodes while providing battery monitoring functionality and an expansion slot for future development. Testing tools for measuring current draw and charge consumption were created along with analysis and processing software. Through their use charge consumption of the power system was drastically lowered and issues in QML-WSN were identified and resolved including the proper shutdown of accelerometers, and incorrect microcontroller unit (MCU) power pin connection. Controlled current profiling revealed unexpected behaviour of nodes and detailed current-voltage relationships. These relationships were utilized with a lifetime projection model to estimate a lifetime between 521-551 days, depending on the mode of operation. The power system and QML-WSN were tested over a long term trial lasting 272+ days in an industrial testbed to monitor an air compressor pump. Environmental factors were found to influence the behaviour of nodes leading to increased charge consumption, while a node in an office setting was still operating at the conclusion of the trail. This agrees with the lifetime projection and gives a strong indication that a 1+ year lifetime is achievable. Additionally, a light-weight charge consumption model was developed which allows charge consumption information of nodes in a distributed WSN to be monitored. This model was tested in a laboratory setting demonstrating +95% accuracy for high packet reception rate WSNs across varying data rates, battery supply capacities, and runtimes up to full battery depletion.

Forms and role of the cluster initiatives in fostering innovation in post-industrial regions: A comparative study of environmental clusters in British West Midlands and Spanish Basque country. ACES Working Paper No. 8, August 2008

The objective of this research is to present cluster initiative approaches in post industrial regions characterized by similar economic history and challenges, with additional emphasis on their role in promoting innovation among regional businesses. The research is based on a comparison study of two environmental industry clusters: Environmental Technology Cluster (ET) from British West Midlands and ACLIMA from Spanish Basque Country. The study analyzes clusters' design and their role in fostering innovation based on environment industry clusters. In both regions environmental industry clusters represent strong potential for further dynamic development with grow opportunities driven by legislation introduced at EU, national or regional levels. The paper compares clusters' heterogeneity, goals and priorities, financing schemes, management structure, types of projects, character of private-public partnerships, challenges, as well as clusters' collaboration at regional/national/international levels. Also focus is given on how the clusters enhance innovation and what types of projects are executed by the regions in this field.

Hazardous material incinerator design criteria/

Mode of access: Internet.

Design manual : neutralization of acid mine drainage /

Mode of access: Internet.

Stem design /

Project pre-SCHOONER.

Stem design and shotcrete, grout, and concrete support /

Project pre-SCHOONER.

Details of machine tool design.

Elementary principles of cone pulleys and belts, by W.L. Cheney -- Cone pulley radii, by J.J. Harman -- Strength of countershafts, by F.B. Kleinhans -- Tumbler gear design, by J. Edgar -- Faults of iron castings, by F.E. Cardullo -- Proportions of machines built in a series of sizes, by S.H. Moore.

Work design.

Includes bibliography.

Effective affective user interface design in games

It is proposed that games, which are designed to generate positive affect, are most successful when they facilitate flow (Csikszentmihalyi 1992). Flow is a state of concentration, deep enjoyment, and total absorption in an activity. The study of games, and a resulting understanding of flow in games can inform the design of non-leisure software for positive affect. The paper considers the ways in which computer games contravene Nielsen's guidelines for heuristic evaluation ( Nielsen and Molich 1990) and how these contraventions impact on flow. The paper also explores the implications for research that stem from the differences between games played on a personal computer and games played on a dedicated console. This research takes important initial steps towards de. ning how flow in computer games can inform affective design.

Modelling of froth transportation in industrial flotation cells: Part I. Development of froth transportation models for attached particles

Modelling of froth transportation, as part of modelling of froth recovery, provides a scale-up procedure for flotation cell design. It can also assist in improving control of flotation operation. Mathematical models of froth velocity on the surface and froth residence time distribution in a cylindrical tank flotation cell are proposed, based on mass balance principle of the air entering the froth. The models take into account factors such as cell size, concentrate launder configuration, use of a froth crowder, cell operating conditions including froth height and air rate, and bubble bursting on the surface. (C) 2004 Elsevier Ltd. All rights reserved.

A preform design method for sheet superplastic bulging with finite element modeling

Superplastic bulging is the most successful application of superplastic forming (SPF) in industry, but the non-uniform wall thickness distribution of parts formed by it is a common technical problem yet to be overcome. Based on a rigid-viscoplastic finite element program developed by the authors, for simulation of the sheet superplastic forming process combined with the prediction of microstructure variations (such as grain growth and cavity growth), a simple and efficient preform design method is proposed and applied to the design of preform mould for manufacturing parts with uniform wall thickness. Examples of formed parts are presented here to demonstrate that the technology can be used to improve the uniformity of wall thickness to meet practical requirements. (C) 2004 Elsevier B.V. All rights reserved.

Modelling of entrainment in industrial flotation cells: the effect of solids suspension

Solids concentration and particle size distribution gradually change in the vertical dimension of industrial flotation cells, subject primarily to the flotation cell size and design and the cell operating conditions. As entrainment is a two-step process and involves only the suspended solids in the top pulp region near the pulp-froth interface, the solids suspension characteristics have a significant impact on the overall entrainment. In this paper, a classification function is proposed to describe the state of solids suspension in flotation cells, similar to the definition of degree of entrainment for classification in the froth phase found in the literature. A mathematical model for solids suspension is also developed, in which the classification function is expressed as an exponential function of the particle size. Experimental data collected from three different Outokumpu tank flotation cells in three different concentrators are well fitted by the proposed exponential model. Under the prevailing experimental conditions, it was found that the solids content in the top region was relatively independent of cell operating conditions such as froth height and air rate but dependent on the cell size. Moreover, the results obtained from the total solids tend to be similar to those from a particular gangue mineral and hence may be applied to all minerals in entrainment calculation. (C) 2004 Elsevier Ltd. All rights reserved.

Design e desenvolvimento de um dispositivo móvel para jogos virtuais em ambiente clínico Fisioterapêutico

A Medicina Física e Reabilitação (MFR) caracteriza-se pela repetição de movimentos, tornando-se monótono e desmotivador. Ao longo dos últimos anos têm sido introduzidas novas estratégias, nomeadamente os jogos virtuais, com o objetivo de tornar esse processo mais lúdico e motivador. A presente dissertação apresenta o desenvolvimento de um dispositivo portátil para a realização de jogos virtuais, que apoie o profissional da MFR nas sessões realizadas quer em ambiente clínico, quer ao domicílio, tendo em consideração aspetos ergonómicos e de usabilidade. Para o desenvolvimento do dispositivo em questão passamos por várias fases, nomeadamente, o levantamento de dispositivos utilizados para a realização de jogos virtuais interactivos em MFR, pelo contacto direto com fisioterapeutas com o intuito de fazer um levantamento das necessidades e características que o produto deveria contemplar. Após o desenvolvimento de três conceitos distintos, selecionamos o que apresentou melhores resultados, considerando as necessidades que os potenciais utilizadores valorizaram, sendo posteriormente desenvolvido e modelado o conceito seleccionado. Numa última fase foi construído um protótipo não funcional do dispositivo e foram realizados testes de usabilidade e validação com potenciais utilizadores do dispositivo. Com o desenvolvimento deste dispositivo pretende-se que estes profissionais, assim como os pacientes, possam usufruir das potencialidades dos jogos virtuais interativos nas suas sessões de uma forma mais simples e cómoda.