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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.
51

Development of a semi-automated ZLC system for rapid screening of adsorbents for carbon capture

Hu, Xiayi January 2012 (has links)
In this dissertation a novel ZLC setup has been developed as part of a DOE-funded grant in collaboration with UOP, to provide rapid screening of novel adsorbent materials for carbon capture (CC). The key features of the new apparatus that was developed are: the use of 5-15 mg of sample and a dual detector system – a thermal conductivity detector (TCD) for single component measurements and a mass spectrometer for studying the influence of water and other impurities. Improvements over previous ZLC apparatuses include: 1. Extension to lower flowrates, i.e. < 3 cc/min, thereby reducing consumption of gases and allowing to run the system under equilibrium control conditions; 2. A new gas dosing system that allows the use of vapours without a chilled bath and bubbler system; 3. A new switching valve system, which prevents leakages; 4. Automated series of experiments, which are implemented using Labview. The new ZLC technique was first applied to provide rapid screening capacity ranking of more than 15 MOF materials from the open literature and three typical zeolites for carbon capture. At the point of interest for flue gas application (38°C, 0.1 bar CO2 partial pressure), Mg/DOBDC was found to outperform significantly all other MOFs and benchmark zeolites at the point of interest in low pressure physisorption of CO2. The ZLC was also used to investigate steaming on Ni/DOBDC as well as see the effect of forming powders into pellets. The new ZLC system also enables one to measure micropore and macropore diffusivity. Experiments were carried out on both powders and pellets of typical MOFs and zeolites. For Co/DOBDC crystals, since the system is close to equilibrium control even at the highest flow rate, a low limit of diffusivity can be estimated. For all the formed samples of Ni/DOBDC and 13X pellets, the results indicate that mass transfer is controlled by macropore diffusion. The ZLC technique can also estimate realistic void fraction and tortuosity values for the pellets. The new ZLC technique was applied to study the stability on the MOF M/DOBDC series. The preliminary water tests showed that all M/DOBDC samples are highly hydrophilic. Therefore in a process design using these MOFs, we conclude that there is a needs to use a guard bed layer to adsorb water or use a gas drying unit before the CO2 capture section of the plant. The ZLC system appears to be extremely useful to accelerate the deactivation of samples due to SOX and NOX impurities. The key advantages are based on the fact that the treatment can be repeated in situ, in a relatively simple way using a very small sample. The results show that in the presence of impurities and water the candidate MOFs undergo significant deactivation. The Ni based material shows the best resistance to degradation. This result indicates further that there would be a need for a drying unit prior to the carbon capture adsorption process.
52

Electron capture dissociation of multiply-charged peptide ions in a fourier transform mass spectrometer.

January 2003 (has links)
Ip Wai-Ho Herman. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 87-90). / Abstracts in English and Chinese. / Abstract (English) --- p.ii / Abstract (Chinese) --- p.iii / Acknowledgement --- p.iv / Declaration --- p.v / Table of Content --- p.vi / List of Tables --- p.ix / List of Figures --- p.x / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Fourier transform ion cyclotron resonance mass spectrometry (FRICR) --- p.2 / Chapter 1.1.1 --- History of FTICR --- p.2 / Chapter 1.1.2 --- Theory of FTICR --- p.4 / Chapter 1.1.3 --- FTICR with electrospray ionization source --- p.10 / Chapter 1.2 --- Tandem mass spectrometry --- p.11 / Chapter 1.2.1 --- Introduction --- p.11 / Chapter 1.2.2 --- Collision-induced dissociation --- p.12 / Chapter 1.2.3 --- Surface-induced dissociation --- p.12 / Chapter 1.2.4 --- Photodissociation --- p.13 / Chapter 1.2.5 --- Blackbody infrared radiative dissociation (BIRD) --- p.13 / Chapter 1.3 --- Electron capture dissociation --- p.13 / Chapter 1.4 --- Recent advances in ECD experiments --- p.15 / Chapter 1.5 --- Outline the present work --- p.17 / Chapter 2. --- EXPERIMENTAL AND INSTRUMENTATION --- p.18 / Chapter 2.1 --- Instrumentation --- p.19 / Chapter 2.1.1 --- Fourier-transform ion cyclotron resonance mass spectrometer --- p.19 / Chapter 2.1.2 --- Vacuum system --- p.19 / Chapter 2.1.3 --- Electrospray ionization source --- p.23 / Chapter 2.1.4 --- Electrostatic ion focusing system --- p.26 / Chapter 2.1.5 --- Infinity cell --- p.28 / Chapter 2.1.6 --- Electron emission source --- p.29 / Chapter 2.1.7 --- Data acquisition system --- p.32 / Chapter 2.2 --- Experimental --- p.32 / Chapter 2.2.1 --- Simple acquisition pulse program --- p.32 / Chapter 2.2.2 --- ECD pulse program with/without collision cooling --- p.35 / Chapter 3. --- OPTIMIZATION OF EXPERIMENTAL PARAMETERS FOR ELECTRON CAPTURE DISSOCIATION --- p.38 / Chapter 3.1 --- Introduction --- p.39 / Chapter 3.2 --- Experimental --- p.40 / Chapter 3.2.1 --- Materials --- p.40 / Chapter 3.2.2 --- Sample preparation --- p.41 / Chapter 3.2.3 --- Instrumentation --- p.41 / Chapter 3.3 --- Results and discussion --- p.42 / Chapter 3.3.1 --- Benchmark conditions --- p.42 / Chapter 3.3.2 --- Effect of the filament heating currents (If) --- p.45 / Chapter 3.3.3 --- Effect of the average filament bias voltages (Vf) --- p.49 / Chapter 3.3.4 --- Effect of the electron irradiation time (te) --- p.53 / Chapter 3.3.5 --- Reduction of the fragment ions intensity --- p.56 / Chapter 3.3.6 --- Effect of the trapping potentials --- p.60 / Chapter 3.4 --- Conclusions --- p.62 / Chapter 4. --- ENHANCEMENT ON ELECTRON CAPTURE DISSOCIATION EFFICIENCY --- p.63 / Chapter 4.1 --- Introduction --- p.64 / Chapter 4.2 --- Experimental --- p.65 / Chapter 4.2.1 --- Materials --- p.65 / Chapter 4.2.2 --- Sample preparation --- p.65 / Chapter 4.2.3 --- Instrumentation --- p.65 / Chapter 4.3 --- Results and discussion --- p.66 / Chapter 4.3.1 --- Effect of the filament position --- p.66 / Chapter 4.3.2 --- Effect of the collision gas pressure --- p.68 / Chapter 4.3.3 --- Effect of the collision gas --- p.73 / Chapter 4.3.4 --- Effect of the electron irradiation at different pulse gas interval --- p.75 / Chapter 4.3.5 --- Effect of the multiple electron irradiation --- p.76 / Chapter 4.3.6 --- Optimized Conditions --- p.79 / Chapter 4.4 --- Conclusions --- p.84 / Chapter 5. --- CONCLUSIONS --- p.85 / Chapter 5.1 --- Conclusions --- p.86 / REFERENCES --- p.87 / APPENDIX --- p.91 / Appendix A Simple pulse sequence program for ESI FTICR-MS experiments --- p.91 / Appendix B Pulse sequence program for ESI FTICR-MS electron capture dissociation --- p.95 / Appendix C Pulse sequence program for ESI FTICR-MS electron capture dissociation experiments with collision cooling --- p.99 / Appendix D Modified pulse sequence program for ESI FTICR-MS electron capture dissociation experiments with a time lag between collision cooling and electron irradiation. --- p.104 / Appendix E Modified pulse sequence program for ESI FTICR-MS electron capture dissociation experiments with multiple irradiation --- p.109
53

Veřejné zakázky jako korupční sektor v RBC modelu / Public Procurements as a Corrupting Sector in RBC Model

Paulus, Michal January 2012 (has links)
The aim of the thesis is to create a RBC model incorporating corrupting sector. The thesis contributes to the few existing DSGE models with corruption by introducing the corrupting sector into the sector of firms and political parties which is regarded as a sector of public procurements where firms bribe politicians for gaining public tenders. This setting is new and is supposed to catch better the phenomenon of political corruption. The model predicts that all shocks that positively affect the economy motivate firms to invest more into the bribes and vice versa. The increase of the overall level of corruption stimulates economy but is leading an economy to the instability. The model also examines the effect of various forms of fiscal spending in the households ' utility function. The model exhibits several non-intuitive results (too high portion of stolen money by firms, stimulation of the economic performance caused by higher corruption and negative holding of government bonds) that should be solved in next research.
54

Measurement of the pion quasi-free radiative capture cross-section on �����O and T[pi]+=165, 220 MeV

Farzanpay, Farzin 05 May 1994 (has links)
Graduation date: 1997
55

A microfluidic device for continuous capture and concentration of pathogens from water

Balasubramanian, Ashwin Kumar 15 May 2009 (has links)
A microfluidic device, based on electrophoretic transport and electrostatic trapping of charged particles, has been developed for continuous capture and concentration of microorganisms from water. A generic design, utilizing mobility and zeta potential measurements of various microorganisms exposed to different environmental conditions and physiological states, was employed. Water and buffer samples at pH values ranging from 5.2–7.0 were seeded with bacteria (E. coli, Salmonella, and Pseudomonas) and viruses (MS-2 and Echovirus). Negative control and capture experiments were performed simultaneously using two identical devices. Both culture based methods and real-time PCR analysis were utilized to characterize the capture efficiency as a function of time, flowrate, and applied electric field. Based on differences between the capture and negative control data, capture efficiencies of 90% to 99% are reported for E. coli, Salmonella, Pseudomonas, and MS-2, while the capture efficiency for Echovirus was around 75%. Overall, the device exhibits 16.67 fold sample volume reduction within an hour at 6 mL/hr. This results in a concentration factor of 15 at 90% capture efficiency. Direct quantification of capture on the anode of the prototype microfluidic device was also performed by particle tracking using fluorescent microscopy. Based on image processing, the capture data at different locations on the electrode surface is quantified as a function of the wall shear stress at these locations, which is calculated using CFD simulations. Finally, the Faradaic processes in the microchannel due to electrochemical reactions are studied to predict the amount of electrophoresis in the system. Scaling of the device to sample 5 L/hr can be achieved by stacking 835 identical microchannels. Power and wetted volume for the prototype and scaled devices are presented. The device can thus function either as a filtration unit or as a sample concentrator to enable the application of real-time detection sensor technologies. The ability to continuously sample water without chemical additives facilitates the use of this device in drinking water distribution systems. This work constitutes the first step in our development of a continuous, microbial capture and concentration system from large volumes of potable water.
56

Skapande av animationer för interaktiv spelmedia genom motion capture

Lau, Kakee January 2013 (has links)
In this thesis I will propose and test a pipeline for creating in-game animations using motion capture technology, with the aim to export to a 3D game engine, such as UDK or similar. Even though there are already established pipelines for creating in-game animations in the game industry, they are not of public knowledge and dissemination of information is hindered by the severe NDA (non-disclosure agreements) imposed on the studios and artists. I will therefore use my experience with game production and as a student, to research and propose an optimal pipeline for developing in-game animation that may be used by other students, researchers and independent game developers. The methodology used to test the pipeline will be a case study based on the student project Synergy, which I am developing with other third year students also attending the Game design Education at Gotland University.
57

A microfluidic device for continuous capture and concentration of pathogens from water

Balasubramanian, Ashwin Kumar 15 May 2009 (has links)
A microfluidic device, based on electrophoretic transport and electrostatic trapping of charged particles, has been developed for continuous capture and concentration of microorganisms from water. A generic design, utilizing mobility and zeta potential measurements of various microorganisms exposed to different environmental conditions and physiological states, was employed. Water and buffer samples at pH values ranging from 5.2–7.0 were seeded with bacteria (E. coli, Salmonella, and Pseudomonas) and viruses (MS-2 and Echovirus). Negative control and capture experiments were performed simultaneously using two identical devices. Both culture based methods and real-time PCR analysis were utilized to characterize the capture efficiency as a function of time, flowrate, and applied electric field. Based on differences between the capture and negative control data, capture efficiencies of 90% to 99% are reported for E. coli, Salmonella, Pseudomonas, and MS-2, while the capture efficiency for Echovirus was around 75%. Overall, the device exhibits 16.67 fold sample volume reduction within an hour at 6 mL/hr. This results in a concentration factor of 15 at 90% capture efficiency. Direct quantification of capture on the anode of the prototype microfluidic device was also performed by particle tracking using fluorescent microscopy. Based on image processing, the capture data at different locations on the electrode surface is quantified as a function of the wall shear stress at these locations, which is calculated using CFD simulations. Finally, the Faradaic processes in the microchannel due to electrochemical reactions are studied to predict the amount of electrophoresis in the system. Scaling of the device to sample 5 L/hr can be achieved by stacking 835 identical microchannels. Power and wetted volume for the prototype and scaled devices are presented. The device can thus function either as a filtration unit or as a sample concentrator to enable the application of real-time detection sensor technologies. The ability to continuously sample water without chemical additives facilitates the use of this device in drinking water distribution systems. This work constitutes the first step in our development of a continuous, microbial capture and concentration system from large volumes of potable water.
58

Solvent reclaiming by sulfate precipitation for CO2 capture

Rafique, Humera Abdul 04 June 2012 (has links)
Sulfate accumulates in the post-combustion CO₂ capture system and must be removed to re-use amine efficiently. Removal of sulfate from the amine-based postcombustion CO₂ capture system through a solvent reclaiming process may reduce CO₂ capture costs. This work determines the solubility of K₂SO₄ and Na₂SO₄ in 2 to 8 m PZ loaded with CO₂ and develops a thermodynamic and process model for the reclaiming process. At 40°C the solubility of Na2SO₄ in 8 m PZ with a CO₂ loading of 0.3 is 0.3 m Na2SO₄ and that of K₂SO₄ is 0.1 m K₂SO₄. Sulfate solubility in PZ solutions is represented by the empirical models: K₂SO₄: ln(Ksp) = 10.53I[superscript 0.3] - 0.98[PZ][subscript T] -3440/T - 2.42 ; Na₂SO₄: ln(Ksp) = 2.137I[superscript0.3] - .6505[PZ][subscript T] -826/T + 265 where [PZ][subscript T] = 2*(molality of PZ). A K₂SO₄ and Na₂SO₄ solubility thermodynamic model was developed in the eNRTL framework in the Fawkes model for PZ/CO₂/H₂O in Aspen Plus[trademark]. The energy cost of the Na process when removing the equivalent of 100 ppm SO₂ from the flue gas, ranging from $0.1-0.5/ton CO₂, was practically the same as the K process(ranging from $0.1-0.8/ton CO₂). The K₂SO₄ recovered in the process can be used as fertilizer. However, the KOH will still cost $0.6/tonne CO₂. If it is not possible to sell the K₂SO₄ as fertilizer because of the impurities that may be present on the K₂SO₄crystals, the chemical cost of the process would increase to $2/tonne CO₂. The chemical cost for the Na case is $0.7/tonne of CO₂. / text
59

Integrating carbon capture and storage with energy production from saline aquifers

Ganjdanesh, Reza 24 June 2014 (has links)
Technologies considered for separating CO₂ from flue gas and injecting CO₂ into saline aquifers are energy intensive, costly, and technically challenging. Production of dissolved natural gas and geothermal energy by extraction of aquifer brine has shown the potential of offsetting the cost of CO₂ capture and storage along with other technical and environmental advantages. The key is to recognize inherent value in the energy content of brine in many parts of the world. Dissolved methane in brine and geothermal energy are two of the sources of energy of many aquifers. For example, geopressured-geothermal aquifers of the US Gulf Coast contain sheer volume of hot brine and dissolved methane. For the same reason, the capacity of these geopressured-geothermal aquifers for storage of CO₂ is remarkable. In this study, various reservoir models were developed from data of Texas and Louisiana Gulf Coast saline aquifers. A systematic study was performed to determine the range of uncertainty of the properties and the prospective of energy production from saline aquifers. Two CO₂ injection strategies were proposed for storage of CO₂ based on the results of simulation studies. Injection of CO₂-saturated brine showed several advantages compared to injection of supercritical CO₂. An overall energy analysis was performed on the closed-loop cycles of capture from power plants, storage of CO₂, and production of energy. The level of cost offset of CCS technology by producing energy from target aquifers strongly depends on the applications of the produced energy. The temperature of the produced brine from geopressured-geothermal aquifers is higher than the temperature of amine stripper column. Calculations for the strategy of injecting CO₂-saturated brine show that the amount of extracted thermal energy from geopressured-geothermal aquifers exceeds the amount of heat required for capturing CO₂ by amine scrubbing. In the process of injecting dissolved CO₂, compressors and pumps should run to pressurize the CO₂ and brine to be transported and achieve the required wellhead pressure. The preliminary estimations indicate that the produced methane provides more energy than that required for pressurization. In the regions where the temperature gradient is normal, the temperature of the produced brine may not be high enough for using in the chemical absorption processes. Separation mechanisms driven by pressure difference are the alternatives for chemical absorption processes since the produced methane can be burned for running the compressors and pumps. Membrane process seems to be the leading technology candidate. The preliminary estimations show that the produced power by extracted methane and geothermal energy exceeds the power needed for membranes, compressors, and pumps. Neither storage of greenhouse gases in saline aquifers nor production of methane and/or geothermal energy from these aquifers are profitable. However, designing a closed looped system by combining methods of capture, storage and production may pay off the whole process at least from the energy point of view. / text
60

Structural properties of aminosilica materials for CO₂ capture

Didas, Stephanie Ann 21 September 2015 (has links)
Increased levels of carbon dioxide in the atmosphere are now widely attributed as a leading cause for global climate change. As such, research efforts into the capture and sequestration of CO2 from large point sources (flue gas capture) as well as the ambient atmosphere (air capture) are gaining increased popularity and importance. Supported amine materials have emerged as a promising class of materials for these applications. However, more fundamental research is needed before these materials can be used in a practically relevant process. The following areas are considered critical research needs for these materials: (i) process design, (ii) material stability, (iii) kinetics of adsorption and desorption, (iv) improved sorbent adsorption efficiency and (v) understanding the effects of water on sorbent adsorption behavior. The aim of the studies presented in this thesis is to further the scientific community’s understanding of supported amine adsorbents with respect to stability, adsorption efficiency and adsorption behavior with water.

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