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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Techno-Economic Study of CO<sub>2</sub> Capture Process for Cement Plants

Hassan, S. M. Nazmul January 2005 (has links)
Carbon dioxide is considered to be the major source of GHG responsible for global warming; man-made CO<sub>2</sub> contributes approximately 63. 5% to all greenhouse gases. The cement industry is responsible for approximately 5% of global anthropogenic carbon dioxide emissions emitting nearly 900 kg of CO<sub>2</sub> for every 1000 kg of cement produced! Amine absorption processes in particular the monoethanolamine (MEA) based process, is considered to be a viable technology for capturing CO<sub>2</sub> from low-pressure flue gas streams because of its fast reaction rate with CO<sub>2</sub> and low cost of raw materials compared to other amines. However, MEA absorption process is associated with high capital and operating costs because a significant amount of energy is required for solvent regeneration and severe operating problems such as corrosion, solvent loss and solvent degradation. This research was motivated by the need to design size and cost analysis of CO<sub>2</sub> capture process from cement industry. MEA based absorption process was used as a potential technique to model CO<sub>2</sub> capture from cement plants. In this research four cases were considered all to reach a CO<sub>2</sub> purity of 98% i) the plant operates at the highest capacity ii) the plant operates at average load iii) the plant operates at minimum operating capacity and iv) switching to a lower carbon content fuel at average plant load. A comparison among four cases were performed to determine the best operating conditions for capturing CO<sub>2</sub> from cement plants. A sensitivity analysis of the economics to the lean loading and percent recovery were carried out as well as the different absorber and striper tray combinations.
2

Techno-Economic Study of CO<sub>2</sub> Capture Process for Cement Plants

Hassan, S. M. Nazmul January 2005 (has links)
Carbon dioxide is considered to be the major source of GHG responsible for global warming; man-made CO<sub>2</sub> contributes approximately 63. 5% to all greenhouse gases. The cement industry is responsible for approximately 5% of global anthropogenic carbon dioxide emissions emitting nearly 900 kg of CO<sub>2</sub> for every 1000 kg of cement produced! Amine absorption processes in particular the monoethanolamine (MEA) based process, is considered to be a viable technology for capturing CO<sub>2</sub> from low-pressure flue gas streams because of its fast reaction rate with CO<sub>2</sub> and low cost of raw materials compared to other amines. However, MEA absorption process is associated with high capital and operating costs because a significant amount of energy is required for solvent regeneration and severe operating problems such as corrosion, solvent loss and solvent degradation. This research was motivated by the need to design size and cost analysis of CO<sub>2</sub> capture process from cement industry. MEA based absorption process was used as a potential technique to model CO<sub>2</sub> capture from cement plants. In this research four cases were considered all to reach a CO<sub>2</sub> purity of 98% i) the plant operates at the highest capacity ii) the plant operates at average load iii) the plant operates at minimum operating capacity and iv) switching to a lower carbon content fuel at average plant load. A comparison among four cases were performed to determine the best operating conditions for capturing CO<sub>2</sub> from cement plants. A sensitivity analysis of the economics to the lean loading and percent recovery were carried out as well as the different absorber and striper tray combinations.
3

"Jess-who-wasn't-Jess" : Double Consciousness and Identity Construction in Helen Oyeyemi's <em>The Icarus Girl</em>

Lundell, Åse January 2010 (has links)
<p>Abstract</p><p>During the last decade many female writers of British decent have focused on identity construction and coming of age. These writers have been especially interested in exploring how people living in the diaspora are trying to cope with their ambivalent feelings towards their mixed cultural heritage. Helen Oyeyemi's <em>The Icarus Girl</em> is one of these novels. The novel depicts a young girl's struggle with the dualism within her, being both British and Nigerian, that threatens to dissolve her self-identity. This essay will explore how <em>The Icarus Girl</em> deals with the theme “double consciousness” (imposed binaries) and how the narrative's structure and stylistic devices enable the story to be read (interpreted) from two different perspectives, thus the narrative's structure offers an ambiguous double reading that corresponds to Jessamy's unresolved doubleness. The first reading suggests that the traumatic experience of “double consciousness“ is left in a status quo, or even being fatal, which in the essay is called the Western reading. The second reading suggests a recovery, i.e. that the young protagonist comes to terms with her mixed cultural heritage, the so-called West-African reading. In pursuing this aim I discuss how “double consciousness” in this novel is a traumatic state of mind transferred from mother to daughter, but also how stylistic devices, belonging to the genre of the fantastic, are used to emphasize the theme and make possible the two different readings.</p>
4

"Jess-who-wasn't-Jess" : Double Consciousness and Identity Construction in Helen Oyeyemi's The Icarus Girl

Lundell, Åse January 2010 (has links)
Abstract During the last decade many female writers of British decent have focused on identity construction and coming of age. These writers have been especially interested in exploring how people living in the diaspora are trying to cope with their ambivalent feelings towards their mixed cultural heritage. Helen Oyeyemi's The Icarus Girl is one of these novels. The novel depicts a young girl's struggle with the dualism within her, being both British and Nigerian, that threatens to dissolve her self-identity. This essay will explore how The Icarus Girl deals with the theme “double consciousness” (imposed binaries) and how the narrative's structure and stylistic devices enable the story to be read (interpreted) from two different perspectives, thus the narrative's structure offers an ambiguous double reading that corresponds to Jessamy's unresolved doubleness. The first reading suggests that the traumatic experience of “double consciousness“ is left in a status quo, or even being fatal, which in the essay is called the Western reading. The second reading suggests a recovery, i.e. that the young protagonist comes to terms with her mixed cultural heritage, the so-called West-African reading. In pursuing this aim I discuss how “double consciousness” in this novel is a traumatic state of mind transferred from mother to daughter, but also how stylistic devices, belonging to the genre of the fantastic, are used to emphasize the theme and make possible the two different readings.
5

Process modeling of very-high-gravity fermentation system under redox potential-controlled conditions

Yu, Fei 31 August 2011
The objective of this study is to evaluate and compare, both technically and economically, various glucose feeding concentrations and different redox potential settings on ethanol production under very-high-gravity (VHG) conditions. Laboratory data were collected for process modeling and two process models were created by two individual process simulators. The first one is a simplified model created and evaluated by Superpro Designer. The second one is an accurate model created by Aspen Plus and evaluated by Aspen Icarus Process Evaluator (Aspen IPE). The simulation results of the two models were also compared. Results showed that glucose feeding concentration at 250±3.95 g/L to the fermentor resulted in the lowest unit production cost (1.479 $/kg ethanol in the Superpro model, 0.764 $/kg ethanol in the Aspen Plus model), with redox potential control effects accounted. Controlling redox potential at -150 mV increased the ethanol yield under VHG fermentation conditions while no significant influences were observed when glucose feeding concentration was less than 250 g/L. Results of product sales analysis indicated that for an ethanol plant with a production rate of 85~130 million kg ethanol/year, only maintaining the glucose feeding concentration to the fermentor at around 250 g/L resulted in the shortest payout period of 5.33 years in average,, with or without redox potential control. If 300±6.42 g/L glucose feeding concentration to the fermentor is applied, it is essential to have the redox potential only controlled at -150 mV in the fermentor to limit the process payout period within 6 years. In addition, fermentation processes with glucose feeding concentration at around 200 g/L to the fermentor were estimated to be unprofitable under all studied conditions. For environmental concerns, two disposal alternatives were presented for CO2 produced during fermentation process rather than emission into atmosphere. One is to sell CO2 as byproduct, which brought 1.52 million $/year income for an ethanol plant with a capacity of 100 million kg ethanol/year. Another option is to capture and transport CO2 to deep injection sites for geological underground storage, which is already a safe and mature technology in North America, and also applicable to many other sites around the world. This would roughly add 4.78 million dollars processing cost annually in the studied scenario. Deep injection of captured CO2 from ethanol plants prevents emission of CO2 into the atmosphere, thus makes it environmental friendly.
6

Process modeling of very-high-gravity fermentation system under redox potential-controlled conditions

Yu, Fei 31 August 2011 (has links)
The objective of this study is to evaluate and compare, both technically and economically, various glucose feeding concentrations and different redox potential settings on ethanol production under very-high-gravity (VHG) conditions. Laboratory data were collected for process modeling and two process models were created by two individual process simulators. The first one is a simplified model created and evaluated by Superpro Designer. The second one is an accurate model created by Aspen Plus and evaluated by Aspen Icarus Process Evaluator (Aspen IPE). The simulation results of the two models were also compared. Results showed that glucose feeding concentration at 250±3.95 g/L to the fermentor resulted in the lowest unit production cost (1.479 $/kg ethanol in the Superpro model, 0.764 $/kg ethanol in the Aspen Plus model), with redox potential control effects accounted. Controlling redox potential at -150 mV increased the ethanol yield under VHG fermentation conditions while no significant influences were observed when glucose feeding concentration was less than 250 g/L. Results of product sales analysis indicated that for an ethanol plant with a production rate of 85~130 million kg ethanol/year, only maintaining the glucose feeding concentration to the fermentor at around 250 g/L resulted in the shortest payout period of 5.33 years in average,, with or without redox potential control. If 300±6.42 g/L glucose feeding concentration to the fermentor is applied, it is essential to have the redox potential only controlled at -150 mV in the fermentor to limit the process payout period within 6 years. In addition, fermentation processes with glucose feeding concentration at around 200 g/L to the fermentor were estimated to be unprofitable under all studied conditions. For environmental concerns, two disposal alternatives were presented for CO2 produced during fermentation process rather than emission into atmosphere. One is to sell CO2 as byproduct, which brought 1.52 million $/year income for an ethanol plant with a capacity of 100 million kg ethanol/year. Another option is to capture and transport CO2 to deep injection sites for geological underground storage, which is already a safe and mature technology in North America, and also applicable to many other sites around the world. This would roughly add 4.78 million dollars processing cost annually in the studied scenario. Deep injection of captured CO2 from ethanol plants prevents emission of CO2 into the atmosphere, thus makes it environmental friendly.
7

Single-Shot, Ultrafast, Multi-Frame X-Ray Imaging of Defect-Bearing Ablator Materials in Extreme Conditions

Hodge, Daniel S. 12 December 2022 (has links)
Characterization of the dynamic behavior of defect-bearing ablator materials subjected to extreme conditions is essential in advancing fusion energy as an reliable and abundant energy source. By understanding how materials evolve spatially and temporally we can minimize hydrodynamic instabilities, which are major contributing factors to energy yield degradation in inertial confinement fusion (ICF) experiments. In this thesis we demonstrate the capabilities of an ultrafast x-ray imaging (UXI) detector, the Icarus V2, where we capture multiple frames of single void-bearing sample compressed by a high-intensity laser shockwave. Using the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS), we conducted two experiments with the x-ray free electron laser (XFEL) multi-pulse mode, delivering four nanosecond-separated pulses to a sample impacted by a laser shockwave, obtaining multiframe images of a single sample in the holographic and direct imaging regime with the UXI detector. In contrast to the low temporal resolution provided by current cameras, the Icarus V2 can capture images with high temporal resolution, which can be used to determine the mechanisms that prevent thermonuclear ignition in ICF experiments. For images captured in the holographic regime at our XFEL energy of 8.23 keV, we realized that the shock front was obscured by strong phase-contrast effects. We recognized that by increasing the XFEL energy while in the holographic regime, more distinguishable features could be revealed behind and along the shock front. Alternatively, in the direct-imaging configuration we discovered that the evolution of microstructural features were directly recognizable in comparison to the holographic regime at lower XFEL energies. Overall, the images captured by the UXI in both regimes demonstrated our ability to obtain multiframe images of processes that occur over several nanoseconds for single samples, which has never been done before. Moreover, the capabilities of the UXI enable extraction of quantitative information over multiple frames, which can help with uncovering the underlying physics involved in high energy density (HED) physics experiments and other experiments involving non-repeatable ultrafast phenomena. Specifically, insight into the behavior of the void can be gained by performing phase retrieval on the images and obtaining the areal density of the materials during laser-shock ablation. Generally, the UXI improves data acquisition speed and operational efficiency, which extends this camera's functionality to experiments that occur at various time scales or experiments that require multiple images to be captured.
8

Heine Steenhagen wöll ju dat wiesen! : die Geschichte eines Ehrgeizigen

Peters, Friedrich Ernst January 2012 (has links)
Heine Steenhagen erzählt die Geschichte von Aufstieg und Fall eines unehelichen Kindes, das in einem holsteinischen Dorf der Jahrhundertwende, dem fiktiven Vollstedt, aufwächst und als Ausgleich für die in der Jugend erlittenen Demütigungen eine militärische Karriere anstrebt, mit der er es seinem Heimatdorf zeigen will („Ik wöll ju dat woll wiesen!“). Als er beginnt, die Sprossen der sozialen Leiter zu erklimmen, wird sein Jugendfeind Jürgen Grootholm zu einem Hindernis auf dem Weg nach oben. Um ihn zu „überholen“, sich an den Vollstedtern zu rächen und die berechnende Margot Kandelhardt heiraten zu können, denunziert Heinrich Steinhagen den Konkurrenten wegen einer Urlaubsüberschreitung in der Hoffnung, dessen Beförderung zu vereiteln und leitet damit sein eigenes tragisches Ende ein.
9

Ozvěny Ovidiových Proměn / Echoes of Ovid's Metamorphoses

Stašová, Ema January 2013 (has links)
The aim of this study is to compare selected episodes of Ovid's Metamorphoses with three works of modern literature containing the theme of metamorphosis, and to follow their intertextual relations, dependency and innovation of Ovidian themes. On the basis of a comparison of the ancient and the modern text it is examined which motives remain constant during centuries and which, on the contrary, are evolving and shifting their meanings. Through the perspective of the Metamorphoses an attempt is made to interpret the works from a less usual angle. The most significant Ovidian characters that are examined in this study are Teiresias, Daphne, Hyacinth, Orpheus, Ceres, Icarus, Callisto and Io.
10

Paradoxia epidemica in the art of Pieter Bruegel the Elder : an investigation into sixteenth-century parody

Cornew, Clive 01 1900 (has links)
Pieter Bruegel the Eider's paintings De verkeerde wereld, Het gevecht tussen Karnava/ en Vasten, Luilekker/and, Dulle Grief and Landschap, met Icarus' val are interpreted as sixteenth-century parodies using the paradoxia epidemica as a tropic means for interpreting the artist's wit, irony, parody and picaresque stance towards his source material and his milieu. Where applicable, other works relating to a particular argument are also discussed. As a result of this investigation, an original contribution has been made in the literature on both Bruegel and parody as a form of visual communication. / Art History, Visual Arts & Musicology / M.A. (History of Art)

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