45 research outputs found

    Wave Propagation in Materials for Modern Applications

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    In the recent decades, there has been a growing interest in micro- and nanotechnology. The advances in nanotechnology give rise to new applications and new types of materials with unique electromagnetic and mechanical properties. This book is devoted to the modern methods in electrodynamics and acoustics, which have been developed to describe wave propagation in these modern materials and nanodevices. The book consists of original works of leading scientists in the field of wave propagation who produced new theoretical and experimental methods in the research field and obtained new and important results. The first part of the book consists of chapters with general mathematical methods and approaches to the problem of wave propagation. A special attention is attracted to the advanced numerical methods fruitfully applied in the field of wave propagation. The second part of the book is devoted to the problems of wave propagation in newly developed metamaterials, micro- and nanostructures and porous media. In this part the interested reader will find important and fundamental results on electromagnetic wave propagation in media with negative refraction index and electromagnetic imaging in devices based on the materials. The third part of the book is devoted to the problems of wave propagation in elastic and piezoelectric media. In the fourth part, the works on the problems of wave propagation in plasma are collected. The fifth, sixth and seventh parts are devoted to the problems of wave propagation in media with chemical reactions, in nonlinear and disperse media, respectively. And finally, in the eighth part of the book some experimental methods in wave propagations are considered. It is necessary to emphasize that this book is not a textbook. It is important that the results combined in it are taken “from the desks of researchers“. Therefore, I am sure that in this book the interested and actively working readers (scientists, engineers and students) will find many interesting results and new ideas

    Energy Technology and Management

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    The civilization of present age is predominantly dependent on energy resources and their utilization. Almost every human activity in today's life needs one or other form of energy. As world's energy resources are not unlimited, it is extremely important to use energy efficiently. Both energy related technological issues and policy and planning paradigms are highly needed to effectively exploit and utilize energy resources. This book covers topics, ranging from technology to policy, relevant to efficient energy utilization. Those academic and practitioners who have background knowledge of energy issues can take benefit from this book

    A Comprehensive Review on Recent Developments of LED Drivers

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    Background: In these recent years, LED lighting has been widely implemented for household and industrial applications. By implementing the correct topology, the performance of a LED driver can be improved in terms of efficiency, power factor, lifespan, size and cost of development. Objective: This paper aims to provide a comprehensive review on the latest trends of LED driver design to serve as a useful guide for design engineers and researchers. Result: Latest research journals and conference proceedings have been reviewed. Conclusion: There are suitable converter topologies for LED drivers of varied power levels, with the flyback converter being the most suitable for applications of less than 100W. When designing the LED driver, considerations must be made on the power factor, efficiency, dimming capability, and lifespan

    Road lighting and future factors

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    Street lighting is currently a growing market that is adapting to and benefiting from numerous technological developments. This dissertation maps the technological factors that will contribute to the future of road lighting in order to aid professionals working in the field, such as lighting designers and engineers. Therefore, this dissertation makes a contribution to knowledge in this area by developing a framework tool (Figure 41. SLSNF - developed on draw.io) to assist stakeholders seeking to implement a new street lighting system. This is based on insights gathered through mixed methods of research from a varied group of professionals associated with street lighting. Furthermore, it also establishes a summarising model (Figure 49. Road lighting and associated factors overview, developed by Ajay Parmar, using www.mindmeister.com) to illustrate all of the considerations surrounding road lighting as a domain. One of the primary focuses of this research targets how lighting professionals interact with lighting standards. Data is collected by mixed methods research of both interviews and a questionnaire. This research confirms that good collaboration amongst a range of different professionals is required for new street lighting projects to develop efficiently. Due to the interdisciplinary nature of these projects, the proposed tool (Figure 41. SLSNF - developed on draw.io), which has been developed as a result of the data collected, will assist those involved to identify and mitigate any possible oversights in a street lighting installation at an early stage

    Resonant Behaviour of Pulse Generators for the Efficient Drive of Optical Radiation Sources Based on Dielectric Barrier Discharges

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    Dielectric barrier discharge (DBD) excimer lamps emit vacuum-UV optical radiation. This work presents novel methods for efficiently operating DBDs with short, high-voltage pulses. Transformer-less systems utilising SiC power semiconductor switches are presented. Pulse frequencies of up to 3.1 MHz and peak inverter efficiencies of 92 % were achieved. The work encloses both mathematical backgrounds of pulsed resonant circuits and practical implementation of low-inductive power stages

    Colour Characterisation of LCD Display Systems

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    The main purpose of this research is to study the colour characterisation of digital display systems. Three distinct models for characterisation (GOG, PLCC and PLVC) are evaluated and compared and for two of these models (GOG and PLCC) two different sets of linearisation samples (either colour-ramps or grey-ramp samples) are used to perform the linearisation. To evaluate these models’ colorimetric measurements are made for 20 different display devices and colour characterization performance is reported as the main measure. Characterisation performance is calculated using several sets of samples including the widely used Macbeth ColorChecker chart and two new charts called Chart4 and Matlab60 (one of which was based on a method previously published by Cheung and Westland and another was based on a new method). A key aspect of this work is that all 256 levels of intensity were measured for the colour-ramps and for the grey-ramp linearisation samples for each of the 20 displays to allow subsampling of these data to explore the effect of the number of linearisation samples on characterisation performance. When the number of linearisation samples used was small (less than 10) the GOG model sometimes resulted in the smallest characterisation colour differences. However, for the PLCC and PLVC models performance tended to increase with the number of linearization samples and both of these models outperformed GOG with more 10 linearisation samples. For the PLCC model, better performance was usually obtained using the grey-ramp linearisation samples rather than using the colour-ramps linearization samples. It was possible, for each of the 20 displays, to reach average ab values that are less than 1.5 (ab <1.5, 90%) or ab < 1.0 (75%); however, the model that yields the best performance is difficult to ascertain in advance (a good strategy would be to evaluate all five models and select the one that performs best for the characterisation of any particular display). However, in the majority of cases, lowest colour differences (ab) were obtained using the PLCC model and all 256 of the grey-ramp samples for linearisation. This work has compared the performance of five different models using a large number of displays and has allowed a number of recommendations to be made about display characterisation. Although the majority of the work in this thesis was based on stationary displays the effect of motion on characterization performance was also explored. This is important since moving images are now commonplace in many applications. The results showed that a moving background has a small, but statistically significant, effect on the colour of patches

    Assessment and Exploitation of the Inherent Value of Waste Electrical and Electronic Equipment (WEEE) for Circular Economy

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    Waste electrical and electronic equipment (WEEE) represents a global environmental and resource-efficiency crisis. However, WEEE is a valuable urban mine of economically, strategically and environmentally important materials e.g. precious metals (PMs) and critical raw materials (CRMs). Economic value derived from WEEE can drive solutions to the ‘WEEE problem’ which are conducive to circular economy, enhance global resource-efficiency, and generate environmental and social benefits. This thesis examines the value of WEEE, and methods for its exploitation to the benefit of global sustainability. The ‘WEEE problem’ is examined in the context of global sustainability, considering environmental & resource-efficiency implications and linear resources use by the electrical & electronic equipment (EEE) industry. Solutions are considered which exploit WEEE as an ‘urban mine’ and embrace circular economy.Within this context, recycling potential of future WEEE is evaluated through projections of PM & Cu content of PCBs, based on temporal trends in historic RAM modules. CRMs are then identified in WEEE and methods of enhancing their recovery through intervention in pre-processing stages of recycling are evaluated. An industrial symbiosis process which recovers Pt from waste thermocouples for use in solar cells is presented as an example of the greater value generation potential offered by circular economy and the potential of such processes to overcome barriers to CRM recovery. Challenges and opportunities in lifecycle optimisation of printable photovoltaics for circular economy is considered as a means of enhancing the industrial ecology of this industry to avoid WEEE generation, reduce primary materials demand and enhance the value derived from these technologies at all stages of their lifecycles. Appropriate battery selection for solar off-grid systems in South Africa is then considered, demonstrating that greater value can be derived from EEE for local economies if compatibility of technologies with local skills and infrastructure for in-use and EoL management

    Best Available Techniques (BAT) Reference Document for Waste treatment Industrial Emissions Directive 2010/75/EU (Integrated Pollution Prevention and Control)

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    The Best Available Techniques (BAT) Reference Document for Waste Treatment is the result of the information exchange since the kick-off meeting which was held from 25 to 28 November 2013. The information collection took place in 2014 and 2015 and the final meeting took place in March 2017. The document includes information on the following waste treatment processes: - Mechanical treatment in shredders of metal waste - Mechanical treatment of VFCs and VHCs containing equipment - Mechanical treatment of waste with calorific value - Aerobic treatment of waste - Anaerobic treatment of waste - Mechanical-Biological treatment of waste (MBT) - Physico-chemical treatment of solid and pasty waste - Re-refining of waste oil - Physico-chemical treatment of waste with calorific value - Regeneration of spent solvents - Physico-chemical and/or biological treatment of water-based liquid waste - Regeneration / recovery of pollution abatement components / Flue-Gas Treatment (FGT) of waste - Recovery of components from spent catalysts - Treatment of excavated contaminated soil - Treatment of POPs-containing waste - Treatment of mercury-containing wasteJRC.B.5-Circular Economy and Industrial Leadershi

    Kuluvien komponenttien eliniät matkustajainformaatiojärjestelmissä

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    The majority of failures and maintenance operations of passenger information systems are caused by the so called consumable components ‒ electrical components or modules which have significantly lower expected lifetimes compared to surrounding electronics in a device. This thesis identifies the consumable components and investigates their useful lifetimes within Teleste Corporation’s on-board systems portfolio. A better understanding of the required maintenance operations within a passenger information systems’ lifetime can be achieved through these approximations. Maintenance and maintainability are becoming more important within the public transport market. Analysis and improvement of maintenance processes are critical in providing efficient support throughout passenger information systems’ long lifetime
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