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Dielectric Barrier Discharge Initiated NOx Abatement In Diesel Engine Exhaust : Towards Achieving Higher Removal EfficiencyMohapatro, Sankarsan 07 1900 (has links) (PDF)
In the last few decades India has advanced socioeconomically due to the rapid growth of industries and automobile sector. This in turn increases the use of fossil fuel and diesel. The atmosphere gets polluted due to the harmful substances, which comes from the burning of fuel. These pollutants can be in the form of gaseous, liquid or solid particulate. Diesel engines, the major source of power in industries and automobiles, play a significant part in causing air pollution. The major pollutants in diesel exhaust are oxides of nitrogen (NOX), sulphur dioxide (SO2), carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), volatile organic compounds (VOC), aldehydes and alcohols. Due to the heavy consumption of diesel as a fuel there is an urgent need to control diesel exhaust.
Diesel exhaust is a complex mixture of several gases and fine particles (commonly known as soot) that contains more than 40 toxic air contaminants. Amongst the gaseous pollutants in diesel exhaust, the major concern and a challenging task is to control oxides of nitrogen, commonly referred to as NOX as it is the major contributor for acid rain, photochemical smog etc. Successful control of emissions from diesel engines is yet to be achieved. The conventional techniques which are available to control emission now are either difficult to operate or does not satisfy the stringent emission standards. This has made the researchers throughout the world to find an alternative and effective non-conventional after treatment technique to reduce diesel engine emission. The failure of conventional techniques lead to the development of non-conventional techniques such as high voltage electric discharge based plasma which has already been proved to be economical and highly efficient in industrial
electrostatic precipitators.
Electric discharge plasma or non-thermal plasma produce energetic electrons which react with background molecules in flue gas leading to active species such as radicals. These radicals being chemically active selectively react with the harmful pollutants facilitating their removal/reduction.
The present thesis work is an attempt to provide a technical solution to achieve
higher removal efficiencies of oxides of nitrogen in the backdrop of shortcomings that exist in conventional technologies to do so. The current thesis describes the research in four stages: (i) studies on NOX removal from diesel exhaust by cross-flow DBD reactor, where design and fabrication of cross-flow DBD reactor, exhaust treatment using cross-flow DBD reactor and exhaust treatment with cascaded plasma-adsorbent technique is described (ii) studies on NOX removal from diesel exhaust by compact discharge plasma sources, where design and fabrication of high frequency high voltage AC (HVAC) using old television flyback transformer, Design and fabrication of high voltage pulse (HVPulse) using automobile ignition coil, exhaust treatment with both HVPulse and HVAC and exhaust treatment with cascaded plasma-adsorbent technique is described (iii) studies on NOX removal from diesel exhaust using solar powered discharge plasma source is described (iv) studies on the NOX removal from diesel exhaust using red mud, where exhaust treatment with red mud and Exhaust treatment cascaded plasma-red mud is covered. The results have been discussed in light of enhancing the NOX removal efficiency for stationary and automobile engine exhausts.
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Návrh lehkého průzkumného letounu bez lidské posádky / Design of Light Unmanned Reconnaissance AircraftKadidlo, Miroslav January 2009 (has links)
The Thesis solves design of light unmanned reconnaissance aircraft carrying 3 kg payload. Based on statistical research chooses the field of long endurance flights, trying to manage problem via solar powered batteries. Difficulities and advantages of this issue are researched and optimal aircraft setup is discussed.
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LIFE CYCLE ASSESSMENT of ERICSSON’s MANAGED RURAL COVERAGE SOLUTION / LIFE CYCLE ASSESSMENT of OFF-GRID SOLAR POWERED BASE STATIONKULTUR, BEGUM January 2013 (has links)
The total number of mobile subscriptions has been announced to reach 6 billion in the market, of which 4 billion are individual users. The rest of the people on earth are potential subscribers that mainly live in rural areas lacking mobile connectivity today. Many of these users do not have access to electricity and have 6 U.S. dollar per month (USD/month) of average revenue per person. Referring to the year 2007, the telecommunication industry had a contribution of 0.6 percent of direct global carbon dioxide (CO2) or 0.4 percent of global carbon dioxide equivalent (CO2e). From 2007 to 2009, the number of off-grid radio base stations located in rural areas went up from 350,000 to 500,000. Nearly all of these sites use diesel generators and large amounts of fossil fuels during the operational stage. In addition the grid sites with diesel back-up were about 0.5 million in 2009. The financial and environmental consequences of the life cycle impact of the diesel fuel depleted can be significant. Adaptation of renewable energy has therefore become important for both environmental and economic reasons. In this master thesis a Life Cycle Assessment of Ericsson’s Managed Rural Coverage (MRC) solution was made. Four main life cycle stages were included: manufacturing, transportation, operation and end-of-life treatment. MRC is an off-grid site solution consisting of electronic communication equipment (radio base station, base station controller, hub, cable) photovoltaic cells, battery, antenna, and constructions part (antenna pole, tower and foundation). This study also includes the satellite connection as well as Ericsson and operator activities in the assessment. The MRC distinguishes itself from the conventional base stations, by its significant decrease of energy consumption in its operational stage as well as the business model around the offering. The assessment in this thesis was carried out in accordance with data retrieved from an Ericsson’s pilot system in Dungunab, Sudan. The ISO 1404X series of LCA standards was followed and Gabi software w used to evaluate the results. The carbon footprint was found to be 0.3 kg CO2e/subscriber for the pilot setup. These calculations were based on an assumption that each pilot site serviced 1000 users. The maximum number of subscribers can be about 3200, which would decrease the life cycle CO2 emissions per user by 2/3. According to the sensitivity analysis the maximum CO2 emissions for a conservative MRC scenario is less than 1 kg CO2e/subscriber. Although this figure represents a very conservative scenario, the result is low in comparison with an average GSM network which has an approximate carbon footprint of 15 kg CO2e/subscriber. It is important to note that the MRC is not intended to replace all conventional macro RBS sites due to limitations in performance and capabilities, but is rather a complement to conventional macro radio base station sites for applicable scenarios. / <p>Thesis registration number: EGI-2013-024MSC EKV941</p>
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Development of an Efficient Solar Powered Unmanned Aerial Vehicle with an Onboard Solar TrackerTegeder, Troy Dixon 10 March 2007 (has links) (PDF)
Methods were developed for the design of a solar powered UAV capable of tracking the sun to achieve maximum solar energy capture. A single-axis solar tracking system was designed and constructed. This system autonomously rotated an onboard solar panel to find the angle of maximum solar irradiance while the UAV was airborne. A microcontroller was programmed and implemented to control the solar tracking system. A solar panel and an efficient airframe capable of housing the solar tracking system was designed and constructed. Each of these subsystems was tested individually with either ground or flight tests. Ultimately, the final assembled system was tested. These tests were used to determine where and when a UAV with an onboard solar tracker would be advantageous over a conventional solar powered UAV with PV cells statically fixed to its wings. The final UAV had a wingspan of 3.2 meters, a length of 2.6 meters, and weighed 4.1 kilograms. Its solar panel provided a maximum power output of 37.7 watts. The predicted system performance, airframe drag, and system power requirements were validated with a battery powered flight test. The UAV's analytical model predicted the drag to be 41% lower than the actual drag found from flight testing. Full system functionality was verified with a solar powered flight test. The results and analysis of the system tests are presented in this thesis. The net energy increase from the solar tracking UAV over a conventional solar powered UAV for the duration of a day is dependent on season and geographical location. The solar tracking UAV that was developed was found to have a maximum net energy gain of 34.5% over a conventional solar powered version of the UAV. The minimum net energy gain of the solar tracking UAV was found to be 0.8%.
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Sustainable Business Model Implementation : Case Study of Female Fish Entrepreneurship and Diffusion of Innovation in Linga Linga, MozambiqueWehbi, Marcus, Ivarsson, David January 2024 (has links)
This study aims to evaluate the diffusion process of a solar-powered refrigerator system, by implementing a sustainable business model as an approach of assessing key features to facilitate the process. The aspiration of this study is to develop a business perspective that can be utilized by companies when aiming to diffuse sustainable enhancing innovations in developing countries with the aim of improving entrepreneurship. The conclusion of this study is based on the alignment of a theoretical framework centered on a sustainable business model and the theory for diffusion of innovation, alongside empirical findings obtained during a case study in Linga Linga, Mozambique. Primary data was acquired through active observations and semi-structured interviews of both female fish entrepreneurs and two organizations with ties to Sweden, operating in Linga Linga. Empirical findings reveled limited availability of new products in Linga Linga, obstructing the diffusion of innovations. Businesses struggles to diffuse innovations in developing countries because of insufficient knowledge of culture differences and the basic needs of the end user. Sustainable development is highlighted as crucial when operating in the Western word but stated as challenging to implement to the same extent in the developing world. The fulfillment of basic needs, rather than operating sustainable and the unfamiliarity with sustainable development as a concept, is found as the reason for the challenge of implementing sustainable development for individuals afflicted by poverty. The alignment of the theoretical framework and the empirical findings in the discussion chapter underscores the benefits of implementing a sustainable business model. Furthermore, the discussion emphasizes the importance of extending the model with knowledge as an additional key feature to comprehensively understand the end users and their basic need in the developing world. This study concludes that utilizing a sustainable business model to assess key features is crucial for facilitating diffusion of innovations, with a particular focus on understanding end user´s basic needs. The study emphasizes the significance of circular economy as a key feature in ensuring durable and reliable products and highlights the importance of comprehensive value chain assessments. Empirical finding concluded that providing solar-powered refrigerator system for the female fish entrepreneurs in Linga Linga could potentially expand their business opportunities, ensuring an increased disposable income, and reduce workload.
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