38 research outputs found
Fluid flow analysis behind heliostat using LES and RANS: A step towards optimized field design in desert regions
No full textTowards negative emissions in the cement industry: A comparative techno-economic assessment of bioenergy with carbon capture and storage as a decarbonization option for the cement industry
No full textNegative emission technologies aim to remove historic CO2 from the atmosphere. Bioenergy with carbon capture and storage (BECCS) is regarded as a possible negative emission technology. This thesis aims to study the technological and economic feasibility of implementing BECCS in the cement industry. Four different types of biomass - rice husk pellets, wood pellets, sewage sludge, and municipal solid waste were chosen to substitute 30% of the coal in a model of a European cement plant. With an emphasis on retrofitting, three CO2 capture technologies, absorption using monoethanol amine (MEA), calcium looping (CaL) based capture, and oxyfuel combustion capture were chosen. This thesis compares the techno-economic performance of the BECCS technologies in a cement plant using the key performance indicators (KPIs) of specific primary energy consumption per CO2 avoided (SPECCA), cement production costs and costs of CO2 avoided. Mass balance results and estimates of capital and operating expenses were used to calculate the KPIs. The parameters for each biomass-CO2 capture combination are compared to each other and compared to the reference value of a cement plant which uses 100% coal without CCS. The results were subjected to sensitivity analysis. CO2 accounting was performed for a defined boundary to estimate the carbon footprint of the BECCS technologies. The BECCS technologies studied have a lower rate of cement production as a result of co-firing biomass in existing boilers. This can be attributed to the low calorific value of biomass. Of the three CO2 capture technologies, oxyfuel combustion capture is the least energy consuming option (1.8 MJ/tCO2, with wood pellets) and the highest range of SPECCA is visible in the case of MEA (8.6 MJ/tCO2, with municipal solid waste). The cement production costs increase by 42 to 89% compared to the costs without CO2 capture. The cost of CO2 avoided is between 45 €/tCO2 (wood pellets with oxyfuel) to a higher range of 96 €/tCO2 (sewage sludge with MEA). The variation in costs is significantly affected by the type of biomass used. CaL technology has a moderate performance in energy consumption and costs. SPECCA obtained for CaL process is in the range of 4.1 to 4.4 MJ/tCO2 and the cost of CO2 avoided is in the range of 57 to 74 €/tCO2. CaL also entails the highest CO2 capture rates, in comparison with MEA and oxyfuel technologies. In terms of total CO2 emissions avoided, CaL based CO2 capture gives the highest CO2 avoided for the system boundary defined. Therefore, when the CO2 removed from the atmosphere through the growth of biomass is included, the net CO2 emissions are the least for CaL capture technology. The reason is the additional thermal energy requirements for the retrofitted CaL process units, which are met with 100% biomass. Although theoretically, a net negative value of CO2 emissions was visible in the case of CaL, it must be noted that upstream process emissions are not included. But in practice, it is still unclear as to whether negative emissions are attainable with the information at hand.Electrical Engineering | Sustainable Energy Technolog
Traffic-responsive signals combined with perimeter control: investigating the benefits
No full textEmpirical and research evidence suggests that traffic-responsive signal control strategies are generally not as efficient in over-saturated traffic conditions characterized by queue spillbacks. Recent studies on (MFD/NFD) have identified a destabilizing gridlock process that arises in congested networks which precludes efficient operation. The MFD has also been used to develop urban traffic control solutions (e.g. perimeter or gating control) to avoid congestion. The purpose of this paper is to explore the benefits of combining gating with locally adaptive traffic signals through micro-simulation of the Chania, Greece traffic network. Two adaptive traffic signal strategies are considered with the perimeter control strategy. The results of the combined gating/adaptive signal control scheme are compared to gating under fixed traffic signals and the implementation of adaptive signals only. The convincing outcome of this simulation study motivates the real-field implementation of gating/perimeter control in the cities, without even changing the existing adaptive control strategies.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
Contentious globalization performance, conflict, and morality in a popular religious movement: religion, performance, and morality in a mass religious movement
No full textThis dissertation is about a popular religious movement in north India – the Kanwar, an annual phenomenon that has grown explosively over the last two decades and now involves more than 12 million people every year. Participants carry water from the river Ganga for libations in Śiva temples in the vicinity of their homes. A majority are young adult males and teenagers of poor and lower middle-class backgrounds, who walk over a hundred miles carrying the sacred water, following varying degrees of ritual obligations, exhibiting their pain, suffering, and fortitude. What brings these millions of young poor men to such a demanding religious practice year after year? Notwithstanding the differences, a wide, cross-disciplinary scholarly consensus regards religious movements as reactionary expressions of collective solidarity in the time of globalization. Scholars reason that globalization causes social anomie, pushing people to embrace traditional affinities such as ethnicity, nationality, or religion. Instead of a “fundamentalist reaction” to social and economic changes, however, my research shows that these practices afford participants opportunities to perform, practice, and prepare for a new configuration of social and economic obligations. They evidence anxious social and psychological preparation for the norms, scarcity, and unpredictable outcomes of poor, informal economic conditions at the critical point of transition into adulthood. These were young adults and teenagers preparing to deliver on their social expectations and obligations to loved ones in social conditions that were often as precarious as they were hierarchical and humiliating. In conditions where the overwhelming majority of workers are informally employed, have few employment, social, and health safeguards, and very limited prospects for stable and respectable employment or life course, these often first steps into adulthood are daunting. At the margins of the economy, the religious phenomenon provided an open and freely accessible, yet challenging, stage – a definite and alternate field – for participants to practice and prove their talents, resolve, and moral sincerity. At the same time, it is also a means to contest the symbolic violence and social inequities of a hierarchical society now dominated by a neo-liberal social ethic, which is both imposing and exclusive.Ph. D.Includes bibliographical referencesby Vikash Sing
Embracing Transparency: A New Editorial Standard for the Use of Artificial Intelligence in Scholarly Publishing
No full textGenerative AI tools are transforming academic publishing, offering efficiency, language support and assistance in complex tasks. NJDVL encourages its responsible use while emphasizing that AI is a tool, not an author. Human accountability, transparency and ethical oversight remain paramount. Full disclosure and human oversight ensure accountability, transparency and integrity, allowing AI to enhance rather than compromise scholarly rigor
Design and implementation of a neural piano-chord analyzer for Matlab
No full textBoston University. University Professors Program Senior theses.PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.2999-01-0
