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University of Johannesburg
1.
Pera, Nicoletta.
A comparative study of energy-related carbon dioxide emissions from South Africa and selected countries.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/1992 
► M.Sc.
Increases in carbon dioxide (CO2) and other atmospheric trace gases, such as methane (CH4), can attribute to what has been called greenhouse warming because…
(more)
▼ M.Sc.
Increases in carbon dioxide (CO2) and other atmospheric trace gases, such as methane (CH4), can attribute to what has been called greenhouse warming because these compounds allow the sun’s energy to reach the surface of the earth, thereby warming it, while preventing much of that energy from being radiated to outer space. Over the past few decades, human activity has increasingly overloaded the Earth’s natural greenhouse system. Energy-related activities are the most significant contributor to greenhouse gas emissions. Emissions from fossil fuel combustion comprise the vast majority of these energy-related emissions. Carbon dioxide is the most significant greenhouse gas for South Africa. Due to the high content of coal in the energy mix, South Africa’s carbon emissions are proportionately greater in comparison with many other countries. The objective of this study is to study and analyse South Africa’s carbon emissions. This research will investigate: • South Africa’s historical trend in carbon emissions • Emissions by source and sector • The study will then deal with comparing South Africa’s energy-related carbon emissions to Argentina and Brazil which are similar middle-income developing countries and Australia and Spain which are developed countries • From here the study will focus on why South Africa’s carbon emissions differ, or are similar to, these other countries and • How South Africa’s carbon emissions impact on the total global carbon emissions. Included is a section discussing background information on the South African energy sector. Data for the South African study was calculated from the energy balances for the country for the study period. For the calculation of the carbon emissions for South Africa the IPCC top-down methodology was used. It can be seen that South Africa’s carbon emissions are still increasing. It was noted however that the values of the carbon emissions differ depending on which emission factors are used. For the International perspective information was obtained from the Internet and plotted on graphs. Information was obtained for the following countries: Argentina, Australia, Brazil, South Africa and Spain. From this study it was seen that South Africa’s carbon dioxide emissions are the highest out of all the countries in this study, while Argentina’s are the lowest. While most countries have energy conservation regulations, energy efficiency standards in South Africa are lacking. The process towards accession to the Kyoto Protocol in South Africa started in February 2000. The South African government has signed the United Nations Framework Convention on Climate Change (UNFCCC) in 1993. It has not yet ratified the Kyoto Protocol, but is currently in the process. This will however still take time and it is for this reason that the clean development mechanism holds the most promise for South Africa to participate in international greenhouse gas emission reduction projects.
Subjects/Keywords: Carbon dioxide
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APA (6th Edition):
Pera, N. (2009). A comparative study of energy-related carbon dioxide emissions from South Africa and selected countries. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/1992
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pera, Nicoletta. “A comparative study of energy-related carbon dioxide emissions from South Africa and selected countries.” 2009. Thesis, University of Johannesburg. Accessed March 02, 2021.
http://hdl.handle.net/10210/1992.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pera, Nicoletta. “A comparative study of energy-related carbon dioxide emissions from South Africa and selected countries.” 2009. Web. 02 Mar 2021.
Vancouver:
Pera N. A comparative study of energy-related carbon dioxide emissions from South Africa and selected countries. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/10210/1992.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pera N. A comparative study of energy-related carbon dioxide emissions from South Africa and selected countries. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/1992
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Vanderbilt University
2.
Douglas, Anna Elisabeth.
Sustainable Manufacturing of Carbon Nanomaterials for Energy Storage Applications.
Degree: PhD, Interdisciplinary Materials Science, 2019, Vanderbilt University
URL: http://hdl.handle.net/1803/11370
► In order to preserve long-term human sustainability on Earth, many researchers have focused significant efforts towards developing technologies that 1) decrease greenhouse gas emissions, and…
(more)
▼ In order to preserve long-term human sustainability on Earth, many researchers have focused significant efforts towards developing technologies that 1) decrease greenhouse gas emissions, and 2) utilize atmospheric
carbon dioxide as a feedstock gas for the production of materials, chemicals, and fuels. While Li-ion batteries have emerged as an ideal technology to reduce emissions through electric vehicles and the storage of renewably-generated energy for electricity, the current cost of Li-ion batteries today limits widespread integration. This cost is fueled mainly by the low earth abundance and high processing cost of Li-ion materials. In this dissertation, I focus on the use of low-cost and earth abundant materials for both Li- and Na- ion battery applications. A platform for the capture and conversion of atmospheric CO2 into solid
carbon structures is developed, with an emphasis on the catalytic growth of
carbon nanotubes (CNTs) through electrochemical routes. Small diameter CNTs are synthesized through the development of an inert anode capable of activating catalytic particles present at the cathode-electrolyte interface, and careful study of dynamic catalytic processes leads to the first mechanistic understandings of electrochemical CNT growth from CO2. Phenomena such as catalyst size dictating the structure of CNTs synthesized and Ostwald ripening of catalysts over time are studied, and electrochemical “pinning” of catalytic particles through the use of high current pulses is demonstrated to drive the formation of small-diameter CNTs with the first observation of single-walled CNTs from CO2 characterized by Raman spectroscopy. Lastly, these CO2-derived CNTs are integrated into Li-ion batteries at both the anode (as the active material) and the cathode (as the conductive additive with Fe-based active materials) and demonstrate a full-cell with a 68% reduction in CO2 emissions associated with Li-ion materials.
Advisors/Committee Members: Douglas Adams (committee member), Greg Walker (committee member), Jason Valentine (committee member), Rizia Bardhan (committee member), Cary Pint (Committee Chair).
Subjects/Keywords: batteries; carbon; carbon dioxide; nanotubes
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APA (6th Edition):
Douglas, A. E. (2019). Sustainable Manufacturing of Carbon Nanomaterials for Energy Storage Applications. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11370
Chicago Manual of Style (16th Edition):
Douglas, Anna Elisabeth. “Sustainable Manufacturing of Carbon Nanomaterials for Energy Storage Applications.” 2019. Doctoral Dissertation, Vanderbilt University. Accessed March 02, 2021.
http://hdl.handle.net/1803/11370.
MLA Handbook (7th Edition):
Douglas, Anna Elisabeth. “Sustainable Manufacturing of Carbon Nanomaterials for Energy Storage Applications.” 2019. Web. 02 Mar 2021.
Vancouver:
Douglas AE. Sustainable Manufacturing of Carbon Nanomaterials for Energy Storage Applications. [Internet] [Doctoral dissertation]. Vanderbilt University; 2019. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1803/11370.
Council of Science Editors:
Douglas AE. Sustainable Manufacturing of Carbon Nanomaterials for Energy Storage Applications. [Doctoral Dissertation]. Vanderbilt University; 2019. Available from: http://hdl.handle.net/1803/11370
3.
Rosengard, Sarah Z.
Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles.
Degree: 2017, MIT and Woods Hole Oceanographic Institution
URL: http://hdl.handle.net/1912/8658
► Particulate organic carbon (POC) in the ocean and mobilized by rivers on land transfers ~0.1% of global primary productivity to the deep ocean sediments. This…
(more)
▼ Particulate organic carbon (POC) in the ocean and mobilized by rivers on land
transfers ~0.1% of global primary productivity to the deep ocean sediments. This small
fraction regulates the long-term carbon cycle by removing carbon dioxide from the
atmosphere for centuries to millennia. This thesis investigates mechanisms of POC
transfer to the deep ocean by analyzing particles collected in transit through two globally
significant carbon reservoirs: the Southern Ocean and the Amazon River Basin. These
endeavors test the hypothesis that organic matter composition controls the recycling and
transfer efficiency of POC to the deep ocean, and illustrate new applications for ramped
pyrolysis/oxidation (RPO), a growing method of POC characterization by thermal
stability. By coupling RPO to stable and radiocarbon isotope analyses of riverine POC, I
quantify three thermally distinct soil organic carbon pools mobilized by the Amazon
River, and evaluate the degradability and fate of these different pools during transport to
the coastal Atlantic Ocean. More directly, RPO analyses of marine samples suggest that
POC transfer in the water column is in fact selective. Observations of consistent
biomolecular changes that accompany transport of phytoplankton-derived organic matter
to depth across the Southern Ocean support the argument for preferential degradation of
specific POC pools in the water column. Combining discussions of POC recycling and
transfer across both marine and terrestrial systems offer new perspectives of thermal
stability as a proxy for diagenetic stability and POC degradation state. The challenges of
interpreting RPO data in these two environments set the stage for applying the technique
to more controlled experiments that trace POC from source to long-term sink.
Subjects/Keywords: Carbon; Carbon dioxide; Atmosphere
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APA ·
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APA (6th Edition):
Rosengard, S. Z. (2017). Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles. (Thesis). MIT and Woods Hole Oceanographic Institution. Retrieved from http://hdl.handle.net/1912/8658
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Rosengard, Sarah Z. “Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles.” 2017. Thesis, MIT and Woods Hole Oceanographic Institution. Accessed March 02, 2021.
http://hdl.handle.net/1912/8658.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Rosengard, Sarah Z. “Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles.” 2017. Web. 02 Mar 2021.
Vancouver:
Rosengard SZ. Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles. [Internet] [Thesis]. MIT and Woods Hole Oceanographic Institution; 2017. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1912/8658.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Rosengard SZ. Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles. [Thesis]. MIT and Woods Hole Oceanographic Institution; 2017. Available from: http://hdl.handle.net/1912/8658
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Manchester
4.
Agredazywczuk, Phillip Armand.
Characterizing current and predicting future variability
of organic matter in runoff from upland peat catchments.
Degree: 2020, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:323978
► Peatlands are a global carbon store that is predicted to be adversely affected by global warming, in which the amount of organic carbon they release…
(more)
▼ Peatlands are a global
carbon store that is
predicted to be adversely affected by global warming, in which the
amount of organic
carbon they release may increase. Indirect
carbon
dioxide fluxes from run-off are likely to be larger and harder to
quantify than direct fluxes. This study simulated future climate
conditions by monitoring a damaged (eroded) catchment paired with
an intact (vegetated) catchment. Bulk
carbon fluxes for the
vegetated and eroded catchment were; 17.57 t km-2 yr-1 and 108.30 t
km-2 yr-1 calculated via interpolation, and 31.57 t km-2 yr-1 and
65.48 t km-2 yr-1 calculated via rating relationships. Attempts
were made to identify differences in hydrology between the
vegetated and eroded catchments, particularly before and after
remediation of the eroded catchment, attempted in 2007. The pH and
hydrogen ion concentration did not differ between the two
catchments. Prior to restoration, time to peak and run-off
coefficients appeared to be unaltered; although, there is a
suggestion that conditions may have improved at the eroded
catchment in 2019. There were also differences between organic
carbon fluxes subdivided into sub-micron size classes
(<1.6>0.2 µm, <0.2 µm>50 kDa, <50>10 kDa and
<10>3 kDa). Fluxes at the vegetated catchment were larger
than the eroded; 48.64 43 t km-2 yr-1 and 34.92 43 t km-2 yr-1. The
distrubution of the flux remained relatively similar, the two
smallest fractions remaining dominant.
Carbon dioxide production
from samples of organic
carbon classifications showed smaller sizes
to have greater lability. Inorganic
carbon, only dissolved
carbon
dioxide considered, was consistently supersaturated on average by
545 ppm at the vegetated catchment and 214 ppm at the eroded.
Carbon dioxide concentrations decreased at both sites during an
event. In a global warming scenario where peat is likely to become
similar to the eroded catchment; the organic
carbon flux is likely
to increase and the sub-micron flux will potentially be smaller,
but the distribution of this will remain the same.
Advisors/Committee Members: Boult, Stephen.
Subjects/Keywords: Peatland; Organic carbon; Carbon dioxide
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APA ·
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Manager
APA (6th Edition):
Agredazywczuk, P. A. (2020). Characterizing current and predicting future variability
of organic matter in runoff from upland peat catchments. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:323978
Chicago Manual of Style (16th Edition):
Agredazywczuk, Phillip Armand. “Characterizing current and predicting future variability
of organic matter in runoff from upland peat catchments.” 2020. Doctoral Dissertation, University of Manchester. Accessed March 02, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:323978.
MLA Handbook (7th Edition):
Agredazywczuk, Phillip Armand. “Characterizing current and predicting future variability
of organic matter in runoff from upland peat catchments.” 2020. Web. 02 Mar 2021.
Vancouver:
Agredazywczuk PA. Characterizing current and predicting future variability
of organic matter in runoff from upland peat catchments. [Internet] [Doctoral dissertation]. University of Manchester; 2020. [cited 2021 Mar 02].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:323978.
Council of Science Editors:
Agredazywczuk PA. Characterizing current and predicting future variability
of organic matter in runoff from upland peat catchments. [Doctoral Dissertation]. University of Manchester; 2020. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:323978
University of Aberdeen
5.
Nowicki, Duncan Alexander.
Hydroxyapatite in carbon capture and CO2 utilisation.
Degree: PhD, 2019, University of Aberdeen
URL: https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153063240005941
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.794120
► There is an immediate need for anthropogenic greenhouse gas emissions to approach net-zero if the impacts of future climate change are to be mitigated. Whilst…
(more)
▼ There is an immediate need for anthropogenic greenhouse gas emissions to approach net-zero if the impacts of future climate change are to be mitigated. Whilst carbon capture & storage (CCS) offers a route for reducing the emission of CO2 from large point sources such as fossil fuel power stations, improvements in the economic case are required before this technology can become viable on a significant scale. Pathways by which the economics of CCS could be improved include the development of more energy-efficient techniques for capture and also via the conversion of captured CO2 gas into value-added products that can be sold to generate revenue. With this in mind, the purpose of this thesis was to assess the potential of the calcium phosphate hydroxyapatite (HA) in carbon capture and CO2 utilisation. A range of carbonated hydroxyapatite (CHA) materials which could have viable real-world applications were prepared. Characterisation of these compositions revealed that phase-pure CHAs with high levels of carbonate incorporation could be prepared using simple, relatively benign, aqueous precipitation reactions at room temperature. Although not essential to achieve high degrees of carbonation in these materials, additional carbonate could be incorporated via a heat treatment in dry CO2. A number of the prepared apatites then proved to be functional CO2 sorbents for carbon capture at 500°C, with relatively stable reactivates over several carbonation-calcination cycles. These tests also revealed that the CO2 carrying capacity of HA could be improved by substituting potassium and carbonate ions for calcium and phosphate ions respectively. Whilst the work presented in this thesis provides clear initial support for HA in carbon capture and CO2 utilisation, further testing of the synthesised materials in prospective applications, including carbon capture, is required before a final conclusion can be reached.
Subjects/Keywords: Hydroxyapatite; Carbon sequestration; Carbon dioxide
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APA (6th Edition):
Nowicki, D. A. (2019). Hydroxyapatite in carbon capture and CO2 utilisation. (Doctoral Dissertation). University of Aberdeen. Retrieved from https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153063240005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.794120
Chicago Manual of Style (16th Edition):
Nowicki, Duncan Alexander. “Hydroxyapatite in carbon capture and CO2 utilisation.” 2019. Doctoral Dissertation, University of Aberdeen. Accessed March 02, 2021.
https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153063240005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.794120.
MLA Handbook (7th Edition):
Nowicki, Duncan Alexander. “Hydroxyapatite in carbon capture and CO2 utilisation.” 2019. Web. 02 Mar 2021.
Vancouver:
Nowicki DA. Hydroxyapatite in carbon capture and CO2 utilisation. [Internet] [Doctoral dissertation]. University of Aberdeen; 2019. [cited 2021 Mar 02].
Available from: https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153063240005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.794120.
Council of Science Editors:
Nowicki DA. Hydroxyapatite in carbon capture and CO2 utilisation. [Doctoral Dissertation]. University of Aberdeen; 2019. Available from: https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153063240005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.794120
University of Manchester
6.
Setterfield-Price, Briony Megan.
Electrochemical Reduction of Carbon Dioxide.
Degree: 2013, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:207603
► The work undertaken involved the exploration of CO2 electroreduction systems, focussing heavily upon electrocatalysis utilising an array of electrochemical, spectroelectrochemical and spectroscopic techniques.The identification and…
(more)
▼ The work undertaken involved the exploration of CO2
electroreduction systems, focussing heavily upon electrocatalysis
utilising an array of electrochemical, spectroelectrochemical and
spectroscopic techniques.The identification and characterisation of
a relatively inexpensive and simple electrocatalyst for CO2
reduction was achieved, with the optimisation and development
undertaken in such a manner that not just the electrocatalytic
species, but also the entire electrochemical system was
investigated, in order to determine and better understand the roles
played by the various components.The complex of interest,
Mo(CO)4bpy, represents the first molybdenum based molecular
electrocatalyst reported to be active toward CO2 reduction, despite
the prominence of Mo in enzymes with analogous function. The
electrochemical characterisation of the complex in the both the
presence and absence of CO2 was undertaken, yielding valuable
information on the redox behaviour of the complex within the
non-aqueous system in which it was employed and highlighting
previously unreported features such as a third reduction and new
reoxidation attributed to the reoxidation of a tricarbonyl anionic
species. Non-aqueous solvents were chosen as they provide greater
CO2 solubility than water with portions of the investigation
undertaken in tetrahydrofuran, THF, then moving to the less widely
used N-methylpyrrolidone, NMP. NMP is significantly less volatile
than THF and has a large negative electrochemical window so is
ideal for looking at reduction processes and, importantly, is also
used as a commercial CO2 scrubbing solvent.Upon addition of CO2 to
the Mo(CO)4bpy system there was an observable lowering of the
overpotential by over 300 mV, and significant increase in CO2
associated current when compared to that for ‘direct’ CO2 reduction
within the same system, at the reduction potential associated with
the first reduction of the tetracarbonyl bipyridyl species. The
confirmation of the anionic radical as the active species was
attained through DFT calculation and EPR spectroelectrochemistry.
Under inert gas the spectrum rapidly generated upon application of
the first reduction potential is consistent with the expected
response for the radical anionic [Mo(CO)4bpy] •−. When the system
is saturated with CO2 this radical is no longer detectable. This
supports the idea that the unpaired electron is transferred from
the [Mo(CO)4bpy]•− to the CO2 molecule and also suggests that this
transfer is rapid as no adduct is detectable via EPR even at
reduced temperature (240 K). This is in keeping with the rate
constants calculated from the voltammetric measurements made. The
stability and activity toward CO2 reduction exhibited by Mo(CO)4bpy
displayed a strong dependence on working electrode material, with
gold proving optimal, indicative of adsorption being significant in
the process.Optimisation of both the catalyst structure and the
solvent and electrolyte system were also explored, as well as the
(somewhat less directly related) comparison of various sources…
Advisors/Committee Members: Dryfe, Robert.
Subjects/Keywords: Electrochemistry; Carbon dioxide
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APA ·
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Manager
APA (6th Edition):
Setterfield-Price, B. M. (2013). Electrochemical Reduction of Carbon Dioxide. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:207603
Chicago Manual of Style (16th Edition):
Setterfield-Price, Briony Megan. “Electrochemical Reduction of Carbon Dioxide.” 2013. Doctoral Dissertation, University of Manchester. Accessed March 02, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:207603.
MLA Handbook (7th Edition):
Setterfield-Price, Briony Megan. “Electrochemical Reduction of Carbon Dioxide.” 2013. Web. 02 Mar 2021.
Vancouver:
Setterfield-Price BM. Electrochemical Reduction of Carbon Dioxide. [Internet] [Doctoral dissertation]. University of Manchester; 2013. [cited 2021 Mar 02].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:207603.
Council of Science Editors:
Setterfield-Price BM. Electrochemical Reduction of Carbon Dioxide. [Doctoral Dissertation]. University of Manchester; 2013. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:207603
7.
Pidaparti, Sandeep R.
A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals.
Degree: 2013, Texas Digital Library
URL: http://hdl.handle.net/1969;
http://hdl.handle.net/2249.1/66777
► To meet future energy needs the use of alternative fuel sources are gaining popularity. The supercritical carbon dioxide Brayton cycle has been proposed as a…
(more)
▼ To meet future energy needs the use of alternative fuel sources are gaining popularity. The supercritical
carbon dioxide Brayton cycle has been proposed as a possible cycle for next generation nuclear and concentrated solar power generation. Large density fluctuations of
carbon dioxide in the supercritical region can be exploited to maintain compressor inlet conditions close to the critical point and thereby, reducing the compressor work and the back work ratio. In order to improve the efficiency of turbomachinery equipment it is important to reduce internal leakage through seals.
A computational study was performed to understand the leakage through seals
subject to large pressure differential using Open source CFD software OpenFOAM. FIT (Fluid Property Interpolation Tables) program is implemented in OpenFOAM to accurately model the properties of CO_(2) required to solve the governing equations. To predict flow behavior in the two phase dome HEM (Homogeneous equilibrium model) is assumed to be valid. Effects of geometrical parameters and operating conditions are isolated from each other and a parametric study was performed in two parts to understand the effects of both geometrical parameters and operating conditions.
Results of the geometrical parameter study indicated that the carryover coefficient of a seal is independent of pressure drop across the seal and is only a function of geometry. A model for carryover was developed as a function of c/s (clearance to pitch ratio) and w_(cavity)/c (cavity width to clearance). It has been identified that the major non-dimensional parameter influencing the discharge through an annular orifice is w_(tooth)/c (tooth width to clearance) and a model for Cd (discharge coefficient) can be developed based on the results we obtained. Flow through labyrinth seals can be considered as a series of annular orifices and cavities. Using this analogy, leakage rate equations can be written for each tooth and the mass flow rate can be modeled as a function of the discharge coefficient under each tooth and the carryover coefficient, which accounts for the turbulent dissipation of kinetic energy in a cavity. The discharge coefficient of first tooth in a labyrinth seal is similar to that of an annular orifice, whereas, the discharge coefficient of the rest of the tooth was found to be a function of the C_(d) of the previous tooth and the carryover coefficient.
To understand the effects of operating conditions, a 1-D isentropic choking model is developed for annular orifices resulting in upper and lower limit curves on a T-s diagram which show the choking phenomenon of flow through a seal. This model was applied to simulations performed on both an annular orifice and a labyrinth seal. It has been observed that the theory is, in general, valid for any labyrinth seal, but the upper and lower limit curves on a T-s diagram depend on number of constrictions. As the number of constrictions increases these two curves move farther away from the critical point.
Finally, some experimental results…
Advisors/Committee Members: Reddy, J. N (advisor).
Subjects/Keywords: Supercritical carbon dioxide
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APA ·
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Manager
APA (6th Edition):
Pidaparti, S. R. (2013). A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals. (Thesis). Texas Digital Library. Retrieved from http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66777
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pidaparti, Sandeep R. “A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals.” 2013. Thesis, Texas Digital Library. Accessed March 02, 2021.
http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66777.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pidaparti, Sandeep R. “A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals.” 2013. Web. 02 Mar 2021.
Vancouver:
Pidaparti SR. A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals. [Internet] [Thesis]. Texas Digital Library; 2013. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66777.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pidaparti SR. A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals. [Thesis]. Texas Digital Library; 2013. Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66777
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
McMaster University
8.
Ren, Yiran.
Poly(N,N-dimethylamino) ethyl methacrylate-grafted silicon: protein resistance and response to carbon dioxide.
Degree: MASc, 2014, McMaster University
URL: http://hdl.handle.net/11375/16311
► This thesis work focused on polymer modification of silicon surface to improve its resistance to protein adsorption. Surface modification was achieved through surface-initiated atom transfer…
(more)
▼ This thesis work focused on polymer modification of silicon surface to improve its resistance to protein adsorption. Surface modification was achieved through surface-initiated atom transfer radical polymerization (SI-ATRP) grafting of poly(N,N-dimethyl amino) ethyl methacrylate (PDMAEMA). Since PDMAEMA is CO2-responsive, CO2 cleaning of the modified surface was also investigated.
SI-ATRP was chosen to graft PDMAEMA brushes on silicon surface for high graft densities and its good control of polymer molecular weight and polydispersity.
Surface characterization of PDMAEMA-modified silicon surfaces included hydrophilicity, layer thickness and surface chemical elemental composition.
Protein adsorption experiments were carried out to evaluate the protein resistance of the modified surfaces. Albumin adsorption from single protein solution, as well as from human plasma, decreased significantly after PDMAEMA grafting, and the adsorbed amount decreased with increasing polymer chain length. The maximum decrease in adsorption of 90% relative to the unmodified silicon, was reached at a graft layer thickness of 40 nm (measured in the dry state). Protein resistance in plasma showed PDMAEMA -modified silicon provided significant resistance to most of the tested proteins. Compared to the PEO-modified surface, the PDMAEMA surface showed much greater resistance to albumin adsorption, but, surprisingly, it adsorbed relatively large amounts of vitronectin and prothrombin. Vitronectin may have been degraded in contact with PDMAEMA-modified surface. Also, it was the only surface out of the four, which adsorbed significant amounts of prothrombin. These unexpected observations indicate further investigation will be required to fully assess the protein-resistant properties of these PDMAEMA surfaces.
CO2-induced protein desorption was also studied. Cleaning experiments were performed by bubbling CO2 into vials containing the protein-adsorbed PDMAEMA-modified surface after 2 h protein solution exposure. Radiolabelling of albumin showed that the CO2 cleaning effectiveness was related with the PDMAEMA thickness. It was found that a surface with graft thickness 20 nm (dry) responded more strongly to CO2 than one with 15 nm thickness. Western blotting results confirmed that CO2 contributed to protein desorption from the PDMAEMA surface.
Thesis
Master of Applied Science (MASc)
Advisors/Committee Members: Brash, J.L., Zhu, Shiping, Biomedical Engineering.
Subjects/Keywords: PDMAEMA; carbon dioxide
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APA (6th Edition):
Ren, Y. (2014). Poly(N,N-dimethylamino) ethyl methacrylate-grafted silicon: protein resistance and response to carbon dioxide. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/16311
Chicago Manual of Style (16th Edition):
Ren, Yiran. “Poly(N,N-dimethylamino) ethyl methacrylate-grafted silicon: protein resistance and response to carbon dioxide.” 2014. Masters Thesis, McMaster University. Accessed March 02, 2021.
http://hdl.handle.net/11375/16311.
MLA Handbook (7th Edition):
Ren, Yiran. “Poly(N,N-dimethylamino) ethyl methacrylate-grafted silicon: protein resistance and response to carbon dioxide.” 2014. Web. 02 Mar 2021.
Vancouver:
Ren Y. Poly(N,N-dimethylamino) ethyl methacrylate-grafted silicon: protein resistance and response to carbon dioxide. [Internet] [Masters thesis]. McMaster University; 2014. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/11375/16311.
Council of Science Editors:
Ren Y. Poly(N,N-dimethylamino) ethyl methacrylate-grafted silicon: protein resistance and response to carbon dioxide. [Masters Thesis]. McMaster University; 2014. Available from: http://hdl.handle.net/11375/16311
9.
Zhang, Yuanyuan.
Carbon Dioxide Functionalization to Acrylate and Formate by
Homogenous Mo and Fe Complexes.
Degree: PhD, Chemistry, 2015, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:674089/
► CO2 functionalization to commodity chemicals and molecular energy provide an powerful mechanism to leverage one of the world most abundant alternative sustainable carbon resources. This…
(more)
▼ CO2 functionalization to commodity chemicals and
molecular energy provide an powerful mechanism to leverage one of
the world most abundant alternative sustainable
carbon resources.
This work focuses on the development of inexpensive earth abundant
iron and molybdenum catalysts for the reduction CO2 toward two key
commodity chemical targets: acrylate and formate. NaEt3BH reduction
of (Triphos)MoCl3 afforded novel molybdenum tetrahydride species
(Triphos)MoH4PPh3, which was found to promote CO2 functionalization
to afford acrylate, propionate and formate species. Mechanistic
study permitted control of the selective to the CO2-ethylene
coupling product. Methods of acrylate elimination from the
molybdenum center were also explored including the use of external
bases and exogenous ligands. Strong bases and strong ligands such
as CO or tBuNC, were found to induce acrylate elimination along
with concomitant generation of acrylates and zero-valent molybdenum
species. The reductive acrylate elimination studies may open
pathways for catalytic acrylate generation. The nature of ancillary
ligand flexibility on CO2-ethylene coupling at molybdenum complexes
was probed by comparative reactivity of two PNP pincer ligands. The
first isolable zero-valent (PhPNpyP)Mo(C2H4)2(CO2) exhibited no
acrylate formation despite having the requisite components
coordinate to the metal. Alternative and more flexible complexes,
(PhPNagostic-CH3P)Mo0(C2H4)2 and (PhPNCH2P)Mo(H)(C2H4)2, were also
studied. CO2 insertion into the Mo-H bond of (PhPNCH2P)Mo(H)(C2H4)2
produced (PhPNCH2P)Mo(C2H4)(κ2-CHO2), which proved a modest and
rare catalyst for CO2 hydrogenation to formate with assistance of
Lewis acid (LA). Further development of catalysts for CO2 reduction
to formate pursued iron(II) carbonyl hydride complexes supported by
either a bifunctional PNP ligand containing a secondary amine, or a
PNP ligand with a tertiary amine that prevents metal-ligand
cooperativity. Both of these species were found to promote the
catalytic hydrogenation of CO2 to formate in the presence of
Brønsted base. A remarkable enhancement in catalytic activity was
observed upon addition of LA co-catalyst in both cases. For the
secondary amine supported system, TON of approximately 9,000 for
formate production was achieved, while for catalysts supported by
the tertiary amine ligand, nearly 60,000 turnovers were observed;
the highest activity reported for an earth abundant catalyst to
date.
Advisors/Committee Members: Bernskoetter, Wesley (Director), Kim, Eunsuk (Reader), Sun, Shouheng (Reader).
Subjects/Keywords: carbon dioxide functionalization
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APA (6th Edition):
Zhang, Y. (2015). Carbon Dioxide Functionalization to Acrylate and Formate by
Homogenous Mo and Fe Complexes. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674089/
Chicago Manual of Style (16th Edition):
Zhang, Yuanyuan. “Carbon Dioxide Functionalization to Acrylate and Formate by
Homogenous Mo and Fe Complexes.” 2015. Doctoral Dissertation, Brown University. Accessed March 02, 2021.
https://repository.library.brown.edu/studio/item/bdr:674089/.
MLA Handbook (7th Edition):
Zhang, Yuanyuan. “Carbon Dioxide Functionalization to Acrylate and Formate by
Homogenous Mo and Fe Complexes.” 2015. Web. 02 Mar 2021.
Vancouver:
Zhang Y. Carbon Dioxide Functionalization to Acrylate and Formate by
Homogenous Mo and Fe Complexes. [Internet] [Doctoral dissertation]. Brown University; 2015. [cited 2021 Mar 02].
Available from: https://repository.library.brown.edu/studio/item/bdr:674089/.
Council of Science Editors:
Zhang Y. Carbon Dioxide Functionalization to Acrylate and Formate by
Homogenous Mo and Fe Complexes. [Doctoral Dissertation]. Brown University; 2015. Available from: https://repository.library.brown.edu/studio/item/bdr:674089/
Colorado State University
10.
Nelson, Robert R.
Impact of aerosols on space-based retrievals of carbon dioxide, The.
Degree: MS(M.S.), Atmospheric Science, 2015, Colorado State University
URL: http://hdl.handle.net/10217/166883
► This work describes an investigation into the impact of aerosols on space-based retrievals of the column-averaged dry-air mole fraction of carbon dioxide (XCO2). It was…
(more)
▼ This work describes an investigation into the impact of aerosols on space-based retrievals of the column-averaged dry-air mole fraction of
carbon dioxide (XCO2). It was initially hypothesized that a simplified non-scattering, or "clear sky", retrieval, which neglects scattering and absorption by clouds and aerosols, could potentially avoid errors and biases brought about by attempting to measure properties of clouds and aerosols when there are none present. Clear sky retrievals have the benefit of being orders of magnitude faster and potentially as accurate as "full physics" retrievals that attempt to gain information about clouds and aerosols. Real data from the Greenhouse Gases Observing Satellite (GOSAT) and simulated data from the Orbiting
Carbon Observatory-2 (OCO-2) were analyzed to find conditions under which a clear sky retrieval might perform as well as a full physics retrieval. It was found that for real GOSAT data the clear sky retrieval performed relatively well over land but not as well over ocean. The opposite conclusion was found for simulated OCO-2 data: it performed well over ocean but poorly over land. For both real GOSAT data and simulated OCO-2 data, high levels of filtering were needed for the clear sky retrieval to be able to perform nearly as well as or better than the full physics retrieval for both land and ocean surfaces. Spectral residuals were then examined to determine if the clear sky algorithm's performance was tied to errors in the spectral fitting. It was found that the clear sky retrievals had larger residuals than the full physics retrievals but that reducing the clear sky residuals by allowing them to fit for a customized residual pattern did little to reduce the XCO2 errors. It was also shown that even very clear scenes can result in small but detectable clear sky residual patterns. A comparison of cloud and aerosol properties measured by the XCO2 retrieval algorithm to aerosol optical depths from the AErosol RObotic NETwork (AERONET) revealed that the algorithm is generally unable to accurately retrieve information about the amount of clouds and aerosols present. Using OCO-2 simulations, it was shown that the algorithm is also only somewhat able to retrieve the heights of the aerosol layers. Information retrieved about individual aerosol types was shown to be even less accurate. Finally, early work in this study prompted investigation into how sensitive the XCO2 retrieval algorithm is to the first guess of aerosol properties. χ² space was explored by varying the first guess of various aerosol parameters. It was revealed that the retrieved aerosol information and XCO2 values can be highly sensitive to the first guess of the state vector, indicating significant nonlinearity in the retrieval's forward model. Two main conclusions were derived from this work. The first is that an analysis of real GOSAT clear sky XCO2 retrievals and simulated OCO-2 clear sky XCO2 retrievals revealed that the clear sky algorithm is generally inferior to the full physics algorithm, except for…
Advisors/Committee Members: O'Dell, Christopher W. (advisor), Denning, A. Scott (committee member), Kummerow, Christian D. (committee member), Lefsky, Michael A. (committee member).
Subjects/Keywords: carbon dioxide; aerosols
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APA (6th Edition):
Nelson, R. R. (2015). Impact of aerosols on space-based retrievals of carbon dioxide, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/166883
Chicago Manual of Style (16th Edition):
Nelson, Robert R. “Impact of aerosols on space-based retrievals of carbon dioxide, The.” 2015. Masters Thesis, Colorado State University. Accessed March 02, 2021.
http://hdl.handle.net/10217/166883.
MLA Handbook (7th Edition):
Nelson, Robert R. “Impact of aerosols on space-based retrievals of carbon dioxide, The.” 2015. Web. 02 Mar 2021.
Vancouver:
Nelson RR. Impact of aerosols on space-based retrievals of carbon dioxide, The. [Internet] [Masters thesis]. Colorado State University; 2015. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/10217/166883.
Council of Science Editors:
Nelson RR. Impact of aerosols on space-based retrievals of carbon dioxide, The. [Masters Thesis]. Colorado State University; 2015. Available from: http://hdl.handle.net/10217/166883
Boston College
11.
Drake, Jessica Lin.
Exploration of Second Sphere Reactivity: Carbon Dioxide
Hydrogenation and Applications of Bis(amidinato)-N-Heterocyclic
Carbene Iron Complexes.
Degree: MS, Chemistry, 2015, Boston College
URL: http://dlib.bc.edu/islandora/object/bc-ir:104492
► Chapter 1. Overview of Carbon Dioxide Hydrogenation for the Production of Formic Acid As the world’s energy demands increase, our resources dwindle and the need…
(more)
▼ Chapter 1. Overview of
Carbon Dioxide Hydrogenation
for the Production of Formic Acid As the world’s energy demands
increase, our resources dwindle and the need for a sustainable
energy source is pertinent. Our current energy infrastructure is
dominated by fossil fuel use. Hydrogen, on the other hand, is
potentially an ideal energy carrier as it is emissions-free when
burned and can be used in fuel cells. Significant advances are
still needed to develop more efficient ways to produce and store
H2. The hydrogenation of CO2 to formic acid and/or methanol
provides an encouraging and reversible approach for a hydrogen
storage material. The first example of homogeneously catalyzed
hydrogenation of
carbon dioxide was in 1976. Over the past 40
years, there has been excellent progress in the development of
catalysts for CO2 hydrogenation. Typically, homogenous catalysts
found to be effect are 2nd and 3rd row transition metals of groups
8-10. In recent years, base-metals (common and inexpensive metals)
have demonstrated promising results. This chapter is designed to
highlight important discoveries throughout the history of
carbon
dioxide hydrogenation. Chapter 2. Development of a Transition Metal
/ N-Heterocyclic Carbene Cooperative System for the Hydrogenation
of
Carbon Dioxide to Formic Acid Over the past few decades, the
conversion of small molecules such as H2, N2, O2, CH4, C2H4, CO,
and CO2 have attracted considerable attention. Many of these
molecules are thermodynamically or kinetically stable and their
usefulness depends on overcoming significant barriers. Frustrated
Lewis pairs and N-heterocyclic carbenes have become common
strategies to activate unreactive small molecule likes CO2 and H2.
However, a hybrid approach utilizing both a transition metal and an
activator has only recently been investigated for the
transformation of small molecules to more useful and complex
compounds. A novel method for these transformations is the use of a
bifunctional catalyst system that incorporates a Lewis basic
N-heterocyclic carbene and a Lewis acidic transition metal. This
chapter highlights our serendipitous discovery that small
quantities of bicarbonate and other inorganic salts enhanced the
productivity of formic acid in CO2 hydrogenation reactions. The
phenomenon was general for many noble-metal catalysts and for one
of the most efficient base-metal hydrogenation catalysts.
Additionally, the synthesis of a transition metal complex bearing a
pendant dihydroimidazolium salt is described. Stoichiometric and
catalytic applications of the newly designed complex were explored
in investigate our Lewis base / transition metal approach to small
molecule activation. Chapter 3. Chemistry of Iron N-Heterocyclic
Carbene Complexes N-heterocyclic carbenes are one of the most
versatile ligands in organometallic chemistry due to their unique
properties as ancillary ligands. Although NHCs are typically potent
σ-donors (a) with minor contributions from π*-backdonation (b),
they also have the ability to accept electron density from the
metal…
Advisors/Committee Members: Jeffery A. Byers (Thesis advisor).
Subjects/Keywords: Carbon Dioxide Hydrogenation
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APA (6th Edition):
Drake, J. L. (2015). Exploration of Second Sphere Reactivity: Carbon Dioxide
Hydrogenation and Applications of Bis(amidinato)-N-Heterocyclic
Carbene Iron Complexes. (Masters Thesis). Boston College. Retrieved from http://dlib.bc.edu/islandora/object/bc-ir:104492
Chicago Manual of Style (16th Edition):
Drake, Jessica Lin. “Exploration of Second Sphere Reactivity: Carbon Dioxide
Hydrogenation and Applications of Bis(amidinato)-N-Heterocyclic
Carbene Iron Complexes.” 2015. Masters Thesis, Boston College. Accessed March 02, 2021.
http://dlib.bc.edu/islandora/object/bc-ir:104492.
MLA Handbook (7th Edition):
Drake, Jessica Lin. “Exploration of Second Sphere Reactivity: Carbon Dioxide
Hydrogenation and Applications of Bis(amidinato)-N-Heterocyclic
Carbene Iron Complexes.” 2015. Web. 02 Mar 2021.
Vancouver:
Drake JL. Exploration of Second Sphere Reactivity: Carbon Dioxide
Hydrogenation and Applications of Bis(amidinato)-N-Heterocyclic
Carbene Iron Complexes. [Internet] [Masters thesis]. Boston College; 2015. [cited 2021 Mar 02].
Available from: http://dlib.bc.edu/islandora/object/bc-ir:104492.
Council of Science Editors:
Drake JL. Exploration of Second Sphere Reactivity: Carbon Dioxide
Hydrogenation and Applications of Bis(amidinato)-N-Heterocyclic
Carbene Iron Complexes. [Masters Thesis]. Boston College; 2015. Available from: http://dlib.bc.edu/islandora/object/bc-ir:104492
University of Canterbury
12.
Bloomberg, Simon.
Looking for Permeability: Mass and Heat Flow Assessment Using High Resolution soil CO₂Flux Surveys within the Taupo Volcanic Zone, New Zealand.
Degree: MS, Geology, 2012, University of Canterbury
URL: http://dx.doi.org/10.26021/7983
► Soil CO2 flux (φCO₂) has increasingly become important as a global exploration and monitoring tool in geothermal and volcanic fields. As CO₂ is the second…
(more)
▼ Soil CO2 flux (φCO₂) has increasingly become important as a global exploration and monitoring tool in geothermal and volcanic fields. As CO₂ is the second most abundant gas in magma-hydrothermal systems, its study is vital for the location or management of those systems. Often one of the only surface expressions is the diffuse gas flux streaming through the soil zone. This thesis reports the investigations into heat and mass at the Rotokawa geothermal field’s thermal area, and White Island volcano’s crater floor hydrothermal system. Surface measurements were taken at high spatial resolution across the fields in a large sampling campaign during the summers of 2010/2011 and 2011/2012. A large dataset was built up which allowed for greater accuracy during geospatial modelling. The models are 2d pixel plots of the soil gas flux and temperature and are used to estimate values of heat and mass flow for the respective magma-hydrothermal systems. Both field areas have a large anomalous diffuse gas flux through the soil zone and related conductive heat flow anomaly, which indicates relative permeability from the source to the surface in these areas. That the rising fluids from the deep source can be sampled at the surface simply is a powerful tool for the exploration and management of these systems. Rotokawa has a diffuse gas release of over 600 t d⁻¹ and an associated heat flow through soil of 37 MWt while White Island has a diffuse gas release of 116 t d⁻¹ and 19.5 MWt of heat flow through the soil. Translating these values to total heat and mass flow values: Rotokawa has a mass flow 125 kg s⁻¹ and a heat flow of 314 MWt and White Island’s crater floor has a mass flow of 100 kg s⁻¹ and a heat flow of 22 MWt. Fluid flow pathways are mapped from the surface and show arcuate and hot spot spatiality, controlled by fault related permeability and structure. soil gas and temperature surveying elucidates Shallow structures that otherwise may have been hidden from status quo surface mapping. The method used in this study is applicable to both known thermal areas and blind thermal areas by addressing not only the flux but also the nature of the soil gases. Further study of White Island has found more evidence for the existence of seawater infiltration of the crater magma-hydrothermal system.
Subjects/Keywords: carbon dioxide; hydrothermal
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APA (6th Edition):
Bloomberg, S. (2012). Looking for Permeability: Mass and Heat Flow Assessment Using High Resolution soil CO₂Flux Surveys within the Taupo Volcanic Zone, New Zealand. (Masters Thesis). University of Canterbury. Retrieved from http://dx.doi.org/10.26021/7983
Chicago Manual of Style (16th Edition):
Bloomberg, Simon. “Looking for Permeability: Mass and Heat Flow Assessment Using High Resolution soil CO₂Flux Surveys within the Taupo Volcanic Zone, New Zealand.” 2012. Masters Thesis, University of Canterbury. Accessed March 02, 2021.
http://dx.doi.org/10.26021/7983.
MLA Handbook (7th Edition):
Bloomberg, Simon. “Looking for Permeability: Mass and Heat Flow Assessment Using High Resolution soil CO₂Flux Surveys within the Taupo Volcanic Zone, New Zealand.” 2012. Web. 02 Mar 2021.
Vancouver:
Bloomberg S. Looking for Permeability: Mass and Heat Flow Assessment Using High Resolution soil CO₂Flux Surveys within the Taupo Volcanic Zone, New Zealand. [Internet] [Masters thesis]. University of Canterbury; 2012. [cited 2021 Mar 02].
Available from: http://dx.doi.org/10.26021/7983.
Council of Science Editors:
Bloomberg S. Looking for Permeability: Mass and Heat Flow Assessment Using High Resolution soil CO₂Flux Surveys within the Taupo Volcanic Zone, New Zealand. [Masters Thesis]. University of Canterbury; 2012. Available from: http://dx.doi.org/10.26021/7983
Oregon State University
13.
Gustafson, Steven Wayne.
Effects of CO₂ enrichment during flowering and podfill on net photosynthesis, dry matter accumulation and yield of beans, Phaseolus vulgaris L.
Degree: PhD, Horticulture, 1983, Oregon State University
URL: http://hdl.handle.net/1957/25518
Subjects/Keywords: Carbon dioxide
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APA (6th Edition):
Gustafson, S. W. (1983). Effects of CO₂ enrichment during flowering and podfill on net photosynthesis, dry matter accumulation and yield of beans, Phaseolus vulgaris L. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/25518
Chicago Manual of Style (16th Edition):
Gustafson, Steven Wayne. “Effects of CO₂ enrichment during flowering and podfill on net photosynthesis, dry matter accumulation and yield of beans, Phaseolus vulgaris L.” 1983. Doctoral Dissertation, Oregon State University. Accessed March 02, 2021.
http://hdl.handle.net/1957/25518.
MLA Handbook (7th Edition):
Gustafson, Steven Wayne. “Effects of CO₂ enrichment during flowering and podfill on net photosynthesis, dry matter accumulation and yield of beans, Phaseolus vulgaris L.” 1983. Web. 02 Mar 2021.
Vancouver:
Gustafson SW. Effects of CO₂ enrichment during flowering and podfill on net photosynthesis, dry matter accumulation and yield of beans, Phaseolus vulgaris L. [Internet] [Doctoral dissertation]. Oregon State University; 1983. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1957/25518.
Council of Science Editors:
Gustafson SW. Effects of CO₂ enrichment during flowering and podfill on net photosynthesis, dry matter accumulation and yield of beans, Phaseolus vulgaris L. [Doctoral Dissertation]. Oregon State University; 1983. Available from: http://hdl.handle.net/1957/25518
University of Utah
14.
Stwertka, Carolyn H.
Carbon dioxide variability within the urban Salt Lake Valley: an observational and modeling study.
Degree: MS, Atmospheric Sciences, 2013, University of Utah
URL: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3469/rec/396
► A multiple-box model was designed to determine how anthropogenic, biological, and meteorologicalprocesses combine to produce diel cycles of carbon dioxide (CO2) concentrations withinthe urban Salt…
(more)
▼ A multiple-box model was designed to determine how anthropogenic, biological, and meteorologicalprocesses combine to produce diel cycles of carbon dioxide (CO2) concentrations withinthe urban Salt Lake Valley (uSLV). The model was forced by an anthropogenic CO2 emissionsinventory, observed winds, sounding-derived mixing depths, and net biological flux estimates basedon temperature, solar radiation, day of year, and ecosystem type. The model was validated usinghourly CO2 data from a network of sensors around the uSLV for years 2005-2009. The modelaccounted for 53% of the observations on an hourly basis and accounted for 90-94% of the meandiel cycle of the observations depending on the season.Salt Lake Valley suffers from prolonged temperature inversions during the winter that trappollutants and gases at the surface. The CO2 network (co2.utah.edu) was compared with the CO2multiple-box model to determine whether the model could capture the main drivers of CO2 variabilityduring the Persistent Cold Air Pool Study (PCAPS). Time-height analyses were performedto facilitate investigation and explanation of CO2 variability during PCAPS intensive observationperiods (IOPs). The analyzed data included atmospheric soundings, CO2 network data, quasiverticalCO2 profiles collected ascending by foot or vehicle, and laser-ceiliometer data.
Subjects/Keywords: Carbon dioxide; Meteorology; Model; Urban
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APA (6th Edition):
Stwertka, C. H. (2013). Carbon dioxide variability within the urban Salt Lake Valley: an observational and modeling study. (Masters Thesis). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3469/rec/396
Chicago Manual of Style (16th Edition):
Stwertka, Carolyn H. “Carbon dioxide variability within the urban Salt Lake Valley: an observational and modeling study.” 2013. Masters Thesis, University of Utah. Accessed March 02, 2021.
http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3469/rec/396.
MLA Handbook (7th Edition):
Stwertka, Carolyn H. “Carbon dioxide variability within the urban Salt Lake Valley: an observational and modeling study.” 2013. Web. 02 Mar 2021.
Vancouver:
Stwertka CH. Carbon dioxide variability within the urban Salt Lake Valley: an observational and modeling study. [Internet] [Masters thesis]. University of Utah; 2013. [cited 2021 Mar 02].
Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3469/rec/396.
Council of Science Editors:
Stwertka CH. Carbon dioxide variability within the urban Salt Lake Valley: an observational and modeling study. [Masters Thesis]. University of Utah; 2013. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3469/rec/396
University of Newcastle
15.
Robinson, Kelly.
A mechanistic study into the reaction between carbon dioxide and amines.
Degree: PhD, 2012, University of Newcastle
URL: http://hdl.handle.net/1959.13/937543
► Research Doctorate - Doctor of Philosophy (PhD)
In this study the amine and carbamate properties that confer enhanced CO₂ absorption capacities, rates and carbamate lability…
(more)
▼ Research Doctorate - Doctor of Philosophy (PhD)
In this study the amine and carbamate properties that confer enhanced CO₂ absorption capacities, rates and carbamate lability has been investigated. This has been achieved using Attenuated Total Reflectance Fourier Transform Infrared (ATR FT-IR) spectroscopy to follow in situ the chemical reactions occurring between CO₂ and a series of heterocyclic monoamines and novel diamines. The monoamines investigated included piperidine and a series of commercially available functionalised piperidine derivatives, e.g. those with methyl-, hydroxyl- and hydroxyalkyl substituents. The diamines investigated included novel hexahyhropyrimidine (HHPY), methyl hexahydropyrimidines (MHHPY and DMHHPY) and hexahydropyridazine (HHPZ); piperazine (PZ), and 2,6- and 2,5- dimethylpiperazines (2,6-DMPZ and 2,5-DMPZ). The effect of structure on CO₂ / amine reactivity was assessed according to a correlation between the infrared active ionic reaction products (carbamate, bicarbonate and protonated amine) and cumulative CO₂ absorption; CO₂ absorption capacity; initial rate of CO₂ absorption; and a correlation between the atomic properties of the amine and carbamate derivative with the infrared spectral data, CO₂ absorption capacity and initial absorption rate. Calculations using B3LYP / 6-31+G** and MP2 / 6-31+G** were performed to investigate the atomic properties of the amines and carbamate derivative. The N-COO- carbamate bond and resonance structure of the carboxylate moiety were analysed. Knowledge of carbamate / bicarbonate speciation during the absorption process enabled the observation of reaction mechanisms as well as the determination of carbamate lability in the studied amine / CO₂ / H₂O systems. We report on the first real-time observation of carbamate hydrolysis in secondary amine absorbent systems.
Advisors/Committee Members: University of Newcastle. Faculty of Science & Information Technology, School of Environmental and Life Sciences.
Subjects/Keywords: carbon dioxide; heterocyclic; amine; carbamate
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APA (6th Edition):
Robinson, K. (2012). A mechanistic study into the reaction between carbon dioxide and amines. (Doctoral Dissertation). University of Newcastle. Retrieved from http://hdl.handle.net/1959.13/937543
Chicago Manual of Style (16th Edition):
Robinson, Kelly. “A mechanistic study into the reaction between carbon dioxide and amines.” 2012. Doctoral Dissertation, University of Newcastle. Accessed March 02, 2021.
http://hdl.handle.net/1959.13/937543.
MLA Handbook (7th Edition):
Robinson, Kelly. “A mechanistic study into the reaction between carbon dioxide and amines.” 2012. Web. 02 Mar 2021.
Vancouver:
Robinson K. A mechanistic study into the reaction between carbon dioxide and amines. [Internet] [Doctoral dissertation]. University of Newcastle; 2012. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1959.13/937543.
Council of Science Editors:
Robinson K. A mechanistic study into the reaction between carbon dioxide and amines. [Doctoral Dissertation]. University of Newcastle; 2012. Available from: http://hdl.handle.net/1959.13/937543
University of Alberta
16.
Zhu, Ren.
Role of Carbon Dioxide in Densification of Oil Sands
Tailings.
Degree: MS, Department of Chemical and Materials
Engineering, 2011, University of Alberta
URL: https://era.library.ualberta.ca/files/th83m0804
► Carbon dioxide (CO2) was shown as a promising alternative for oil sands tailings treatment with economical and environmental benefits. This thesis aims to understand the…
(more)
▼ Carbon dioxide (CO2) was shown as a promising
alternative for oil sands tailings treatment with economical and
environmental benefits. This thesis aims to understand the role of
CO2 addition in settling and densification of oil sands tailings.
In this study, CO2 was pressurized into two industrial whole
tailings. The optimal initial settling rate, supernatant clarity
and solids content of sediment were achieved at CO2 partial
pressure of about 100 kPa. Increasing the processing temperature
improved the effects of CO2 on the settling of tailings. The
improvement on settling and densification of tailings by CO2 was
mainly attributed to pH reduction, which led to a decrease in the
value of zeta potential of the fines. On the other hand, CO2
bubbles formed by dissolved gas under super-saturation pressure
caused a less clear supernatant by disturbing the formed sediments.
The limit of CO2 sequestration by oil sands tailings was
experimentally evaluated.
Subjects/Keywords: oil sands tailings; carbon dioxide
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APA (6th Edition):
Zhu, R. (2011). Role of Carbon Dioxide in Densification of Oil Sands
Tailings. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/th83m0804
Chicago Manual of Style (16th Edition):
Zhu, Ren. “Role of Carbon Dioxide in Densification of Oil Sands
Tailings.” 2011. Masters Thesis, University of Alberta. Accessed March 02, 2021.
https://era.library.ualberta.ca/files/th83m0804.
MLA Handbook (7th Edition):
Zhu, Ren. “Role of Carbon Dioxide in Densification of Oil Sands
Tailings.” 2011. Web. 02 Mar 2021.
Vancouver:
Zhu R. Role of Carbon Dioxide in Densification of Oil Sands
Tailings. [Internet] [Masters thesis]. University of Alberta; 2011. [cited 2021 Mar 02].
Available from: https://era.library.ualberta.ca/files/th83m0804.
Council of Science Editors:
Zhu R. Role of Carbon Dioxide in Densification of Oil Sands
Tailings. [Masters Thesis]. University of Alberta; 2011. Available from: https://era.library.ualberta.ca/files/th83m0804
17.
Yang, Fengyuan.
SUPERCRITICAL CARBON DIOXIDE (scCO2) PROCESSING OF DISPERSED POLYMER/CLAY NANOCOMPOSITES: STRUCTURAL AND BARRIER PROPERTIES.
Degree: 2014, Johns Hopkins University
URL: http://jhir.library.jhu.edu/handle/1774.2/37884
► Improved polymeric packaging materials have significantly economic and environmental impact on food, beverage and other industries. In this dissertation, we developed polymer/clay nanocomposites, by incorporating…
(more)
▼ Improved polymeric packaging materials have significantly economic and environmental impact on food, beverage and other industries. In this dissertation, we developed polymer/clay nanocomposites, by incorporating impermeable layered silicates into polymeric matrix to enhance barrier properties. We utilized the unique properties of super critical
carbon dioxide (scCO2) to exfoliate clay layers and improve polymer-clay interactions, which are two key challenges in the field of nanocomposites. Firstly, the scCO2 processing was applied to pre-disperse various commercial Cloisite® clays, the effects of scCO2 processing and chemical and physical properties of clay particles on clay pre-dispersion were investigated and the extent of clay pre-dispersion was assessed by SEM, WAXD and TGA. We found that the scCO2 processing results in pre-dispersion of organic modified clays regardless what kind of modifier on them. The degree of dispersion of different kind of clays actually is
a competitive result between
carbon dioxide philicity and modifiers interaction. In addition, TGA data confirm that the scCO2 processing does not remove surface modifiers from clays, which maintain good solubility of clay in organic solvent and compatibility with organic phase. Secondly, the pre-dispersed clay particles were solution blending with polystyrene (PS) to form nanocomposites, whose structural physical properties were characterized and evaluated by WAXD and TEM. The effects of scCO2 processing, clay dispersion, modification and fraction on improvements of physical properties such as rheology and barrier of nanocomposites were investigated. In addition, structure-barrier properties relationship was assessed based on several phenomenological models. In particular, we identified that 10A is the best reinforcement for improving PS barrier properties. Microstructural and barrier properties characterizations revealed that scCO2 processed clays prevent reorganization of platelets
and lead to more homogenously clay dispersion with improved interfaces. As the increase of clay fraction and dispersion, gas permeation decreased continuously, in this study ~83% reduction of permeation had been achieved with 3.1 vol% of scCO2 processed clays with a calculated effective aspect ratio of 109. Finally, the concept of scCO2 processing reinforced polymer/clay nanocomposites based on PS matrix was translated to more complex melting extrusion of engineering polymers, such as polyethylene terephthalate (PET) and high density polyethylene (HDPE). The effects of scCO2 processing, clay dispersion, modification and fraction and temperature on improvements of structural and physical properties of matrix were investigated and discussed. 30B and 20A were identified as the best candidate for improving barrier properties of PET and HDPE respectively. Similarly, we found that scCO2 processed clays lead to more homogenously clay dispersion with improved interfaces. Nevertheless, unlike
previous research, permeation of PET did not decrease continuously with increase of clay…
Advisors/Committee Members: Rangaramanujam, Kannan (advisor).
Subjects/Keywords: Nanocomposites; Super critical carbon dioxide
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APA (6th Edition):
Yang, F. (2014). SUPERCRITICAL CARBON DIOXIDE (scCO2) PROCESSING OF DISPERSED POLYMER/CLAY NANOCOMPOSITES: STRUCTURAL AND BARRIER PROPERTIES. (Thesis). Johns Hopkins University. Retrieved from http://jhir.library.jhu.edu/handle/1774.2/37884
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Yang, Fengyuan. “SUPERCRITICAL CARBON DIOXIDE (scCO2) PROCESSING OF DISPERSED POLYMER/CLAY NANOCOMPOSITES: STRUCTURAL AND BARRIER PROPERTIES.” 2014. Thesis, Johns Hopkins University. Accessed March 02, 2021.
http://jhir.library.jhu.edu/handle/1774.2/37884.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Yang, Fengyuan. “SUPERCRITICAL CARBON DIOXIDE (scCO2) PROCESSING OF DISPERSED POLYMER/CLAY NANOCOMPOSITES: STRUCTURAL AND BARRIER PROPERTIES.” 2014. Web. 02 Mar 2021.
Vancouver:
Yang F. SUPERCRITICAL CARBON DIOXIDE (scCO2) PROCESSING OF DISPERSED POLYMER/CLAY NANOCOMPOSITES: STRUCTURAL AND BARRIER PROPERTIES. [Internet] [Thesis]. Johns Hopkins University; 2014. [cited 2021 Mar 02].
Available from: http://jhir.library.jhu.edu/handle/1774.2/37884.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Yang F. SUPERCRITICAL CARBON DIOXIDE (scCO2) PROCESSING OF DISPERSED POLYMER/CLAY NANOCOMPOSITES: STRUCTURAL AND BARRIER PROPERTIES. [Thesis]. Johns Hopkins University; 2014. Available from: http://jhir.library.jhu.edu/handle/1774.2/37884
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Oregon State University
18.
Culberson, Charles Henry.
Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater.
Degree: MS, Oceanography, 1968, Oregon State University
URL: http://hdl.handle.net/1957/28203
Subjects/Keywords: Carbon dioxide
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APA (6th Edition):
Culberson, C. H. (1968). Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/28203
Chicago Manual of Style (16th Edition):
Culberson, Charles Henry. “Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater.” 1968. Masters Thesis, Oregon State University. Accessed March 02, 2021.
http://hdl.handle.net/1957/28203.
MLA Handbook (7th Edition):
Culberson, Charles Henry. “Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater.” 1968. Web. 02 Mar 2021.
Vancouver:
Culberson CH. Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater. [Internet] [Masters thesis]. Oregon State University; 1968. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1957/28203.
Council of Science Editors:
Culberson CH. Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater. [Masters Thesis]. Oregon State University; 1968. Available from: http://hdl.handle.net/1957/28203
Oregon State University
19.
Kaster, Suzanne Snead Perry.
Absorption of carbon dioxide in water using a multiple stage cross current packed column.
Degree: MS, Chemical Engineering, 1981, Oregon State University
URL: http://hdl.handle.net/1957/42201
► A cascade crosscurrent column, packed with Pall rings, was employed for carbon dioxide absorption from a carbon dioxide-rich air phase by contacting with water. Absorption…
(more)
▼ A cascade crosscurrent column, packed with Pall rings, was
employed for
carbon dioxide absorption from a
carbon dioxide-rich
air phase by contacting with water. Absorption efficiency was
presented as the percentage of CO₂ removed versus gas flow rates for
constant liquid to gas ratios (L/G).
Curves were developed for an L/G molar flow ratio of 25 and 50.
The curve for an L/G ratio of 25 exhibited a distinct mass transfer
transition point which corresponded to the flow transition point, the
point when cross flow first appears. The curve for L/G ratio of 50
did not exhibit the mass transfer transition point, however, the
efficiency changes were small and the mass transfer transition point
may well have been masked by experimental error even though a flow
transition point was observed.
The mass transfer data was found comparable to
carbon dioxide air-water data obtained by another investigator using a countercurrent
column. This information coupled with the higher throughput and
lower pressure drop attributed to the crosscurrent column make it an
attractive alternative to conventional towers.
Advisors/Committee Members: Wicks, Charles E. (advisor).
Subjects/Keywords: Carbon dioxide
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APA (6th Edition):
Kaster, S. S. P. (1981). Absorption of carbon dioxide in water using a multiple stage cross current packed column. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/42201
Chicago Manual of Style (16th Edition):
Kaster, Suzanne Snead Perry. “Absorption of carbon dioxide in water using a multiple stage cross current packed column.” 1981. Masters Thesis, Oregon State University. Accessed March 02, 2021.
http://hdl.handle.net/1957/42201.
MLA Handbook (7th Edition):
Kaster, Suzanne Snead Perry. “Absorption of carbon dioxide in water using a multiple stage cross current packed column.” 1981. Web. 02 Mar 2021.
Vancouver:
Kaster SSP. Absorption of carbon dioxide in water using a multiple stage cross current packed column. [Internet] [Masters thesis]. Oregon State University; 1981. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1957/42201.
Council of Science Editors:
Kaster SSP. Absorption of carbon dioxide in water using a multiple stage cross current packed column. [Masters Thesis]. Oregon State University; 1981. Available from: http://hdl.handle.net/1957/42201
Oregon State University
20.
Jones, Mark Murrison.
The solubility of carbon dioxide in waters of low alkalinity.
Degree: MS, Oceanography, 1969, Oregon State University
URL: http://hdl.handle.net/1957/29013
► A graphical method, based on a set of acid-base titrations, is presented for the determination of the carbon dioxide speciation in natural solutions. The application…
(more)
▼ A graphical method, based on a set of acid-base titrations, is
presented for the determination of the
carbon dioxide speciation in
natural solutions. The application of this method, in conjunction
with measurements of the partial pressure of
carbon dioxide with
which our solutions were in equilibrium permitted the calculation
of the solubility of
carbon dioxide.
The results of these calculations in dilute solutions of 1.00
meq/l alkalinity gave a value of 0.070 for the solubility at 25° C.
This value is considerably higher than that obtained by Harned and
Davis (1943), 0.0345, for solutions of zero alkalinity. Our experimental
method, with the conditions used by Harned and Davis, yielded
a result which agreed well with theirs.
It is concluded that the solubility of
carbon dioxide within the
alkalinity range found in many fresh waters, is greater than was
previously believed. The reason for this higher solubility is not
known. It is shown that it cannot be ascribed to a specific cation
effect.
Advisors/Committee Members: Pytkowicz, R. M. (advisor).
Subjects/Keywords: Carbon dioxide
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APA (6th Edition):
Jones, M. M. (1969). The solubility of carbon dioxide in waters of low alkalinity. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/29013
Chicago Manual of Style (16th Edition):
Jones, Mark Murrison. “The solubility of carbon dioxide in waters of low alkalinity.” 1969. Masters Thesis, Oregon State University. Accessed March 02, 2021.
http://hdl.handle.net/1957/29013.
MLA Handbook (7th Edition):
Jones, Mark Murrison. “The solubility of carbon dioxide in waters of low alkalinity.” 1969. Web. 02 Mar 2021.
Vancouver:
Jones MM. The solubility of carbon dioxide in waters of low alkalinity. [Internet] [Masters thesis]. Oregon State University; 1969. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1957/29013.
Council of Science Editors:
Jones MM. The solubility of carbon dioxide in waters of low alkalinity. [Masters Thesis]. Oregon State University; 1969. Available from: http://hdl.handle.net/1957/29013
Cornell University
21.
Valentine, Helen.
Assessing The Use Of Sedation Prior To Carbon Dioxide Euthanasia Of Mice.
Degree: M.S., Veterinary Medicine, Veterinary Medicine, 2011, Cornell University
URL: http://hdl.handle.net/1813/29142
► Carbon dioxide (CO2) administration is the most commonly used method of euthanasia of mice in research, yet questions remain regarding whether CO2 euthanasia is associated…
(more)
▼ Carbon dioxide (CO2) administration is the most commonly used method of euthanasia of mice in research, yet questions remain regarding whether CO2 euthanasia is associated with pain and stress. This study aims to characterize the level of pain and stress induced in mice during CO2 euthanasia, and to determine if premedication with acepromazine or midazolam, or anesthetic induction with isoflurane, alters these levels during CO2 euthanasia. Mice were assigned to one of six euthanasia groups: (control) CO2 only at a flow rate that displaces 20% of the cage volume per minute (V/min); premedication with acepromazine (5 mg/kg), midazolam (5 mg/kg), or saline followed by 20% V/min CO2; induction with 5% isoflurane followed by > 100% V/min CO2; or 100% V/min CO2 only. Behavioral measures of stress included ultrasonic sound recordings and analysis of video recordings, by an observer blinded to group identity, to assess increased respiratory effort, increased activity, and pain. Physiological parameters of stress were assessed by measuring plasma adrenocorticotropic hormone (ACTH) and corticosterone levels immediately post-euthanasia. Finally, we assessed the acute neuromolecular marker of pain and stress, c-fos, by quantitative PCR. The use of premedication with acepromazine or midazolam did not significantly alter behavioral indicators of stress but did significantly induce a higher level of c-fos expression in the brain compared to 20% V/min CO2 alone. Furthermore, the use of isoflurane induction prior to CO2 euthanasia significantly increased stress in the mice based on both behavioral and neuromolecular indicators. These data strongly indicate that in comparison to the other modalities analyzed in this study, 20% V/min CO2 is a humane, rapid euthanasia method that is not associated with significant pain or stress in mice.
Advisors/Committee Members: Maurer, Kirk (chair), Bailey, Michele M. (committee member).
Subjects/Keywords: Mice; Euthanasia; Carbon Dioxide
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APA (6th Edition):
Valentine, H. (2011). Assessing The Use Of Sedation Prior To Carbon Dioxide Euthanasia Of Mice. (Masters Thesis). Cornell University. Retrieved from http://hdl.handle.net/1813/29142
Chicago Manual of Style (16th Edition):
Valentine, Helen. “Assessing The Use Of Sedation Prior To Carbon Dioxide Euthanasia Of Mice.” 2011. Masters Thesis, Cornell University. Accessed March 02, 2021.
http://hdl.handle.net/1813/29142.
MLA Handbook (7th Edition):
Valentine, Helen. “Assessing The Use Of Sedation Prior To Carbon Dioxide Euthanasia Of Mice.” 2011. Web. 02 Mar 2021.
Vancouver:
Valentine H. Assessing The Use Of Sedation Prior To Carbon Dioxide Euthanasia Of Mice. [Internet] [Masters thesis]. Cornell University; 2011. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1813/29142.
Council of Science Editors:
Valentine H. Assessing The Use Of Sedation Prior To Carbon Dioxide Euthanasia Of Mice. [Masters Thesis]. Cornell University; 2011. Available from: http://hdl.handle.net/1813/29142
Cornell University
22.
Tsai, Wen-Chyan.
Characterization And Applications Of Liposomes Microencapsulated By A Novel Supercritical Fluid Process.
Degree: PhD, Food Science and Technology, 2015, Cornell University
URL: http://hdl.handle.net/1813/41168
► A novel supercritical fluid (SCF) process, composed of SCF extraction, rapid expansion of a supercritical solution, and vacuum-driven cargo loading based on the Bernoulli principle,…
(more)
▼ A novel supercritical fluid (SCF) process, composed of SCF extraction, rapid expansion of a supercritical solution, and vacuum-driven cargo loading based on the Bernoulli principle, was successfully developed for liposomal microencapsulation. It aimed to be a non-toxic and continuous process based on the flow-through design and without usage of any organic solvent. Soy lecithin and cholesterol in a 10:1 mass ratio were dissolved in SC-CO2 at 20 ± 0.5 MPa and 60 °C. The phospholipids/cholesterol-laden SC-CO2 was then passed through a 1000-micron nozzle and immediately mixed with the cargo solution to form liposomes. Liposome size, zeta potential, and encapsulation efficiency (EE) were characterized as functions of the operating parameters. The results showed that the average liposome size varied from 400-500 nm to 9001200 nm when the pressure was increased from 8.27 to 16.55 MPa. For the liposomal microencapsulation of 0.2 M glucose solution, it was found that the highest EE of 31.6 % was reached at 12.41 MPa, 90 °C, and 0.25 ml/second of cargo loading rate. Under a confocal laser scanning microscope, the large unilamellar vesicles (LUVs) and multivesicular vesicles (MVVs) accounted for a majority of the liposomal emulsion produced by this novel SCF technique. Simultaneous microencapsulation of hydrophilic and lipophilic compounds in the integrated liposomes were also conducted for versatile applications of this novel SCF process. The liposomal microencapsulation was run via a 1000-micron jetting nozzle at 12.41 MPa, 90 °C, and 0.25 ml/second of the cargo loading rate. Vitamins C and E were used as model hydrophilic and lipophilic compounds, respectively, for characterization and storage-stability evaluation of the SCF-based liposomes. The average vesicle size of vitamins C and E microencapsulated liposomes was 951.02 nm with a zeta potential of -51.87 mV. The EE for vitamin C was 32.97 %, and EE for vitamin E was 99.32 %. During 20 days of storage at 4 °C, the EEs were found to slightly decrease by 1.76 % and 0.88 %, for vitamins C and E, respectively. The simultaneous microencapsulation of hydrophilic and lipophilic compounds in the liposomes was successfully demonstrated using this SCF process.
Advisors/Committee Members: Rizvi,Syed S H (chair), Tabacchi,Mary Huddleston (committee member), Liu,Rui-Hai (committee member).
Subjects/Keywords: supercritical carbon dioxide; liposome; microencapsulation
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APA (6th Edition):
Tsai, W. (2015). Characterization And Applications Of Liposomes Microencapsulated By A Novel Supercritical Fluid Process. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/41168
Chicago Manual of Style (16th Edition):
Tsai, Wen-Chyan. “Characterization And Applications Of Liposomes Microencapsulated By A Novel Supercritical Fluid Process.” 2015. Doctoral Dissertation, Cornell University. Accessed March 02, 2021.
http://hdl.handle.net/1813/41168.
MLA Handbook (7th Edition):
Tsai, Wen-Chyan. “Characterization And Applications Of Liposomes Microencapsulated By A Novel Supercritical Fluid Process.” 2015. Web. 02 Mar 2021.
Vancouver:
Tsai W. Characterization And Applications Of Liposomes Microencapsulated By A Novel Supercritical Fluid Process. [Internet] [Doctoral dissertation]. Cornell University; 2015. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1813/41168.
Council of Science Editors:
Tsai W. Characterization And Applications Of Liposomes Microencapsulated By A Novel Supercritical Fluid Process. [Doctoral Dissertation]. Cornell University; 2015. Available from: http://hdl.handle.net/1813/41168
Texas A&M University
23.
Pidaparti, Sandeep R.
A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals.
Degree: MS, Mechanical Engineering, 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151884
► To meet future energy needs the use of alternative fuel sources are gaining popularity. The supercritical carbon dioxide Brayton cycle has been proposed as a…
(more)
▼ To meet future energy needs the use of alternative fuel sources are gaining popularity. The supercritical
carbon dioxide Brayton cycle has been proposed as a possible cycle for next generation nuclear and concentrated solar power generation. Large density fluctuations of
carbon dioxide in the supercritical region can be exploited to maintain compressor inlet conditions close to the critical point and thereby, reducing the compressor work and the back work ratio. In order to improve the efficiency of turbomachinery equipment it is important to reduce internal leakage through seals.
A computational study was performed to understand the leakage through seals
subject to large pressure differential using Open source CFD software OpenFOAM. FIT (Fluid Property Interpolation Tables) program is implemented in OpenFOAM to accurately model the properties of CO_(2) required to solve the governing equations. To predict flow behavior in the two phase dome HEM (Homogeneous equilibrium model) is assumed to be valid. Effects of geometrical parameters and operating conditions are isolated from each other and a parametric study was performed in two parts to understand the effects of both geometrical parameters and operating conditions.
Results of the geometrical parameter study indicated that the carryover coefficient of a seal is independent of pressure drop across the seal and is only a function of geometry. A model for carryover was developed as a function of c/s (clearance to pitch ratio) and w_(cavity)/c (cavity width to clearance). It has been identified that the major non-dimensional parameter influencing the discharge through an annular orifice is w_(tooth)/c (tooth width to clearance) and a model for Cd (discharge coefficient) can be developed based on the results we obtained. Flow through labyrinth seals can be considered as a series of annular orifices and cavities. Using this analogy, leakage rate equations can be written for each tooth and the mass flow rate can be modeled as a function of the discharge coefficient under each tooth and the carryover coefficient, which accounts for the turbulent dissipation of kinetic energy in a cavity. The discharge coefficient of first tooth in a labyrinth seal is similar to that of an annular orifice, whereas, the discharge coefficient of the rest of the tooth was found to be a function of the C_(d) of the previous tooth and the carryover coefficient.
To understand the effects of operating conditions, a 1-D isentropic choking model is developed for annular orifices resulting in upper and lower limit curves on a T-s diagram which show the choking phenomenon of flow through a seal. This model was applied to simulations performed on both an annular orifice and a labyrinth seal. It has been observed that the theory is, in general, valid for any labyrinth seal, but the upper and lower limit curves on a T-s diagram depend on number of constrictions. As the number of constrictions increases these two curves move farther away from the critical point.
Finally, some experimental results…
Advisors/Committee Members: Reddy, J. N. (advisor), Ranjan, Devesh (advisor), Vierow, Karen (committee member).
Subjects/Keywords: Supercritical carbon dioxide; labyrinth seals
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APA (6th Edition):
Pidaparti, S. R. (2013). A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151884
Chicago Manual of Style (16th Edition):
Pidaparti, Sandeep R. “A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals.” 2013. Masters Thesis, Texas A&M University. Accessed March 02, 2021.
http://hdl.handle.net/1969.1/151884.
MLA Handbook (7th Edition):
Pidaparti, Sandeep R. “A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals.” 2013. Web. 02 Mar 2021.
Vancouver:
Pidaparti SR. A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals. [Internet] [Masters thesis]. Texas A&M University; 2013. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1969.1/151884.
Council of Science Editors:
Pidaparti SR. A Computational Study on the Leakage of Supercritical Carbon Dioxide through Labyrinth Seals. [Masters Thesis]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151884
Texas A&M University
24.
Tovar, Francisco.
Experimental Investigation on the Use of Water Soluble Polyacrylamides as Thickeners During CO_(2) WAG EOR.
Degree: MS, Petroleum Engineering, 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/153449
► CO_(2) flooding often results in poor sweep efficiency due to the high mobility ratio caused by its low viscosity. To mitigate this problem, alternate injection…
(more)
▼ CO_(2) flooding often results in poor sweep efficiency due to the high mobility ratio caused by its low viscosity. To mitigate this problem, alternate injection of water and CO_(2) slugs (WAG) is widely applied. Recently, numerical simulation and core flood experiments in heavy oil indicate that the use of chemicals in the water slug may improve mobility control during WAG. Therefore, stability studies of common polymers used for EOR applications in CO_(2) saturated environments becomes necessary. Also, the possibility to extrapolate the benefits observed in heavy oil to light and medium oil reservoirs needs to be assessed as they gather the majority of the existing CO_(2) applications.
This thesis presents an evaluation of the use of polymers as water thickeners during CO_(2). The work has been divided into three stages: An investigation on the stability of acrylamide based polymers exposed to CO_(2) for 328 days at 122 °F. The determination of the MMP for the system crude oil – CO_(2) using the slim tubing technique in a fast approach that employs a short column of 20 ft in length. And the execution of 12 core flooding experiments under miscible and immiscible conditions, in homogeneous and heterogeneous rock.
We conclude that polyacrylamide based polymers can resist the presence of CO_(2). HPAM was able to retain 54% of its original viscosity after 215 days at 122 °F. PAM - ATBS increased its viscosity to 104% of its original viscosity after 328 days. A MMP of 1563 psia was calculated, which has a good correlation to previous laboratory measurements and EOS predictions for live oil. The core flooding experiments gave insights regarding the role of miscibility, frontal advance rate, heterogeneity and water viscosity on the viscous fingering of CO_(2) into the oil and suggested that thickening the water during WAG could be beneficial in highly heterogeneous formations. The limitations to scale reservoir heterogeneity prevented us to reach a fully understanding of the process. An approach combining numerical simulation with experimental work is recommended.
Advisors/Committee Members: Barrufet, Maria A (advisor), Schechter, David S (advisor), Nars-El-Din, Hisham (committee member).
Subjects/Keywords: Carbon Dioxide; EOR; polymer
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APA (6th Edition):
Tovar, F. (2014). Experimental Investigation on the Use of Water Soluble Polyacrylamides as Thickeners During CO_(2) WAG EOR. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153449
Chicago Manual of Style (16th Edition):
Tovar, Francisco. “Experimental Investigation on the Use of Water Soluble Polyacrylamides as Thickeners During CO_(2) WAG EOR.” 2014. Masters Thesis, Texas A&M University. Accessed March 02, 2021.
http://hdl.handle.net/1969.1/153449.
MLA Handbook (7th Edition):
Tovar, Francisco. “Experimental Investigation on the Use of Water Soluble Polyacrylamides as Thickeners During CO_(2) WAG EOR.” 2014. Web. 02 Mar 2021.
Vancouver:
Tovar F. Experimental Investigation on the Use of Water Soluble Polyacrylamides as Thickeners During CO_(2) WAG EOR. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1969.1/153449.
Council of Science Editors:
Tovar F. Experimental Investigation on the Use of Water Soluble Polyacrylamides as Thickeners During CO_(2) WAG EOR. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153449
Penn State University
25.
Gething, Brad Allen.
The computational modeling of supercritical carbon dioxide flow in solid wood materials
.
Degree: 2011, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/12532
► The use of supercritical carbon dioxide (SC CO2) as a solvent to deliver chemicals to porous media has shown promise in various industries. Recently, efforts…
(more)
▼ The use of supercritical
carbon dioxide (SC CO2) as a solvent to deliver chemicals to porous media has shown promise in various industries. Recently, efforts by the wood treating industry have been made to use SC CO2 as a replacement to more traditional methods of chemical preservative delivery. Previous studies have shown that the SC CO2 pressure treatment process is capable of impregnating solid wood materials with chemical preservatives, but concentration gradients of preservative often develop during treatment. Widespread application of the treatment process is unlikely unless the treatment inconsistencies can be improved for greater overall treating homogeneity.
The development of a computational flow model to accurately predict the internal pressure of CO2 during treatment is integral to a more consistent treatment process. While similar models that attempt to describe the flow process have been proposed by Ward (1989) and Sahle-Demessie (1994), neither have been evaluated for accuracy. The present study was an evaluation of those models. More specifically, the present study evaluated the performance of a computational flow model, which was based on the viscous flow of compressible CO2 as a single phase through a porous medium at the macroscopic scale. Flow model performance was evaluated through comparisons between predicted pressures that corresponded to internal pressure development measured with inserted sensor probes during treatment of specimens. Pressure measurements were applied through a technique developed by Schneider (2000), which utilizes epoxy-sealed stainless steel tubes that are inserted into the wood as pressure probes. Two different wood species were investigated as treating specimens, Douglas-fir and shortleaf pine.
Evaluations of the computational flow model revealed that it is sensitive to input parameters that relate to both processing conditions and material properties, particularly treating temperature and wood permeability, respectively. This sensitivity requires that the input parameters, principally permeability, be relatively accurate to evaluate the appropriateness of the phenomenological relationships of the computational flow model. Providing this stipulation, it was observed that below the region of transition from CO2 gas to supercritical fluid, the computational flow model has the potential to predict flow accurately. However, above the transition region, the model does not fully account for the physics of the flow process, resulting in prediction inaccuracy.
One potential cause for the loss of prediction accuracy in the supercritical region was attributed to a dynamic change in permeability that is likely caused by an interaction between the flowing SC CO2 and the wood material. Furthermore, a hysteresis was observed between the pressurization and depressurization stages of treatment, which cannot be explained by the current flow model. If greater accuracy in the computational flow model is desired, a more complex approach to the model is necessary, which would…
Advisors/Committee Members: John Jack Janowiak, Dissertation Advisor/Co-Advisor, John Jack Janowiak, Committee Chair/Co-Chair, Nicole Robitaille Brown, Committee Member, Jeffery J Morrell, Committee Member, Turgay Ertekin, Committee Member, Virendra Puri, Committee Member.
Subjects/Keywords: supercritical carbon dioxide wood treatment
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APA (6th Edition):
Gething, B. A. (2011). The computational modeling of supercritical carbon dioxide flow in solid wood materials
. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/12532
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Gething, Brad Allen. “The computational modeling of supercritical carbon dioxide flow in solid wood materials
.” 2011. Thesis, Penn State University. Accessed March 02, 2021.
https://submit-etda.libraries.psu.edu/catalog/12532.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gething, Brad Allen. “The computational modeling of supercritical carbon dioxide flow in solid wood materials
.” 2011. Web. 02 Mar 2021.
Vancouver:
Gething BA. The computational modeling of supercritical carbon dioxide flow in solid wood materials
. [Internet] [Thesis]. Penn State University; 2011. [cited 2021 Mar 02].
Available from: https://submit-etda.libraries.psu.edu/catalog/12532.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gething BA. The computational modeling of supercritical carbon dioxide flow in solid wood materials
. [Thesis]. Penn State University; 2011. Available from: https://submit-etda.libraries.psu.edu/catalog/12532
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Queens University
26.
Blaser, Amy.
Spatial and temporal patterns of carbon dioxide exchange for a wet sedge plant community, Melville Island, NU
.
Degree: Geography, 2016, Queens University
URL: http://hdl.handle.net/1974/13987
► Wet sedge meadows are the most productive vegetation communities in the High Arctic. Preliminary research suggests that this vegetation type is a net carbon sink,…
(more)
▼ Wet sedge meadows are the most productive vegetation communities in the High Arctic. Preliminary research suggests that this vegetation type is a net carbon sink, yet the controls – and the scale at which those controls act – are not well understood. If warming of the High Arctic enhances or limits wet sedge growth, we may observe changes in the percentage of land area occupied by these meadows, resulting in significant alterations to the carbon balance of high arctic landscapes.
Here, the factors controlling carbon dioxide (CO2) exchange of wet sedge meadows are examined at different spatial and temporal scales and environmental data is used to create predictive models of CO2 exchange. Automated and static CO2 exchange systems recorded CO2 exchange at three wet sedge sites at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, NU, from June to August, 2014. In conjunction, time-series normalized difference vegetation index (NDVI) data were collected to quantify the phenological stage of the wet sedge vegetation type through the growing season, and soil temperature, air temperature, photosynthetically active radiation (PAR), soil moisture, and active layer depth were measured.
Net ecosystem exchange (NEE) measurements indicated dominant plant uptake through photosynthesis, and spectrally separable ‘wet’ and ‘dry’ sedge areas yielded significantly different NEE values at both sampling scales. NDVI measurements indicated that spring greening and peak summer biomass differed between wet and dry areas, but that NDVI was not strongly related to CO2 exchange trends in these systems. Abiotic factors such as air and soil temperature and soil moisture – varying over time and space throughout the season – influenced CO2 exchange to varying degrees at each scale.
Predictive models of ecosystem carbon flux were created using NDVI in combination with environmental measurements as predictors. This facilitated an evaluation, at two scales, of the drivers of CO2 exchange in these communities – both spatially and temporally. Static chamber measurements (bi-weekly) were unsuccessful in modelling CO2 exchange, but autochamber measurements (half-hourly) provided reasonable predictions. I suggest, though, that linear multivariate-regression models are insufficient for capturing variation in these systems, and that more complex models may provide greater success in the future.
Subjects/Keywords: Arctic
;
climate change
;
carbon dioxide
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APA (6th Edition):
Blaser, A. (2016). Spatial and temporal patterns of carbon dioxide exchange for a wet sedge plant community, Melville Island, NU
. (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/13987
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Blaser, Amy. “Spatial and temporal patterns of carbon dioxide exchange for a wet sedge plant community, Melville Island, NU
.” 2016. Thesis, Queens University. Accessed March 02, 2021.
http://hdl.handle.net/1974/13987.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Blaser, Amy. “Spatial and temporal patterns of carbon dioxide exchange for a wet sedge plant community, Melville Island, NU
.” 2016. Web. 02 Mar 2021.
Vancouver:
Blaser A. Spatial and temporal patterns of carbon dioxide exchange for a wet sedge plant community, Melville Island, NU
. [Internet] [Thesis]. Queens University; 2016. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1974/13987.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Blaser A. Spatial and temporal patterns of carbon dioxide exchange for a wet sedge plant community, Melville Island, NU
. [Thesis]. Queens University; 2016. Available from: http://hdl.handle.net/1974/13987
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Johannesburg
27.
Barradas, Sean.
CO2 activation and functionalization.
Degree: 2012, University of Johannesburg
URL: http://hdl.handle.net/10210/5754
► M.Sc.
An Acinetobacter sp. strain RFB1 isolated in our laboratory has been shown to have the ability to metabolise inorganic cyanide salts, CO 2, and…
(more)
▼ M.Sc.
An Acinetobacter sp. strain RFB1 isolated in our laboratory has been shown to have the ability to metabolise inorganic cyanide salts, CO 2, and bicarbonate. The enzyme aggregate responsible for the conversion of these substrates, is located extra-cellularly. Resolution of the extra-cellular complex, a crude enzyme filtrate, was attempted in order to characterise the protein responsible for the reduction of CO 2. The crude enzyme filtrate was separated by means of molecular exclusion chromatography and afforded three fractions with molecular masses ranging from 76 000 to 191 000. Analysis by SDS-electrophoresis, showed that the first protein fraction contained more than ten proteins. Certain of these proteins were identified in the second fraction and other proteins in the third protein fraction. This implies that some denaturation already occurred during molecular exclusion separation. The functionali7ation of CO 2 by protein fractions 1 and 3 supports this argument, and, in addition , cyanide ions were only reduced by fractions 1 and 2. Fatty acids, ranging with chainlengths between C5 and C25, were shown to be present and certain fatty acids were unequivocally identified by GC-mass spectroscopy as the products resulting from CO2 functionali7ation and carbon-carbon bond formation. Ferrous ions, in an optimal concentration of 250 gg cm', were necessary and served as an essential ingredient of the reaction mixture. A rather unusual result was, however, that apart from an initial, relatively small uptake of Fe(II), significant amounts of Fe(III) were not formed and the Fe(II) concentration remained approximately constant during the reaction. This implies that the formed Fe(M) is rapidly reduced to Fe(II) again. Spectroscopic measurements, furthermore, strongly suggested the involvement of an iron-sulphur cluster in a cyclic redox process wherein both Fe(II) and Fe(III) are involved. Carefully conducted experiments pointed to light as the outside source of energy. Qualitative similarities with an artificial photosynthetic process, formulated earlier by J-M. Lehlliii, can be drawn and used partly to explain the experimental results.
Subjects/Keywords: Carbon dioxide; Reduction (Chemistry); Acinetobacter
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Export
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APA (6th Edition):
Barradas, S. (2012). CO2 activation and functionalization. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/5754
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Barradas, Sean. “CO2 activation and functionalization.” 2012. Thesis, University of Johannesburg. Accessed March 02, 2021.
http://hdl.handle.net/10210/5754.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Barradas, Sean. “CO2 activation and functionalization.” 2012. Web. 02 Mar 2021.
Vancouver:
Barradas S. CO2 activation and functionalization. [Internet] [Thesis]. University of Johannesburg; 2012. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/10210/5754.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Barradas S. CO2 activation and functionalization. [Thesis]. University of Johannesburg; 2012. Available from: http://hdl.handle.net/10210/5754
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
28.
Miao, Yu.
CO₂ Reduction in Microscale-Based Corona Reactor : Experiments and Modeling.
Degree: PhD, Chemical Engineering, 2016, Oregon State University
URL: http://hdl.handle.net/1957/59109
► Global warming is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Creating useful applications for CO₂…
(more)
▼ Global warming is becoming an increasingly important environmental concern and
CO₂ is considered as the major cause of global warming. Creating useful applications
for CO₂ would generate alternatives to merely venting CO₂ to the atmosphere, and
decreasing the
carbon intensity of human activities. Among various methods of CO₂
utilization, conversion of CO₂ to value-added chemical products is the most attractive.
In this study, microtechnology and application of corona discharge are combined and
introduced into CO₂ reduction process.
Experiments were conducted before the design and manufacture of the microreactor
to determine the configuration of the reactor, products of reaction and effect of active
volume ratio: (1) it is proved that through-gas corona discharge are much simpler to
implement than through-liquid, especially those with high solubility of CO₂; (2) the
V-I curve for the corona discharge reactors is characterized by a transition from a high
voltage low current (which we call spark discharge) to a low voltage high current state
(the corona discharge state), with this transition used as a diagnostic of the reactor
operation in the corona discharge mode even when direct observation of the discharge
is not practical; (3) the products for the reduction of dry CO₂ are
carbon monoxide
(CO) and oxygen (O₂), while for the reduction of wet CO₂, methane (CH4) is also formed in addition to these two products; (4) a larger active volume ratio results in
higher conversion of CO₂ to products.
Based on the experimental results listed above, two multi-discharge microscale-based
corona reactors were designed and manufactured. We found that for a needle-to-plate
gap of 110μm, at the voltage of 0.840kV and current of 0.62mA, a flow of CO₂ and
H₂O mixture (flow rate of CO₂ = 50sccm, CO₂-to-H₂O molar ratio = 1:2) can result in
5.5~6% conversion of CO₂ (with 40~50% conversion within the active volume of the
reactor) with energy efficiency of 85~95%. The influence of the three main factors,
namely the power applied to the reactor (specific points of the V-I curve used), flow
rate of CO₂, and CO₂-to-H₂O molar ratio, on the performance and energy efficiency
of the reactor were investigated. It was found that (1) the glow regime (or corona
regime) is the optimal operation regime for this process from both conversion and
energy efficiency perspectives, with higher current in this regime resulting in higher
CO₂ conversion; (2) lower flow rate of CO₂ can result in higher conversion with lower
energy efficiency, and conversely, the highest energy efficiency is achieved at the
highest flow rate; (3) the conversion of CO₂ increases as the CO₂-to-H₂O molar ratio
decreases, but the highest energy efficiency is achieved when this ratio matches the
ratio of stoichiometric numbers.
A numerical model of the process reflecting the geometry, momentum balance,
material balance and kinetics inside the reactor was developed to help understand the
chemical reaction process. The reaction scheme was modelled as…
Advisors/Committee Members: Jovanovic, Goran (advisor), Arnadottir, Liney (committee member).
Subjects/Keywords: CO2 reduction; Carbon dioxide mitigation
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APA ·
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Manager
APA (6th Edition):
Miao, Y. (2016). CO₂ Reduction in Microscale-Based Corona Reactor : Experiments and Modeling. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/59109
Chicago Manual of Style (16th Edition):
Miao, Yu. “CO₂ Reduction in Microscale-Based Corona Reactor : Experiments and Modeling.” 2016. Doctoral Dissertation, Oregon State University. Accessed March 02, 2021.
http://hdl.handle.net/1957/59109.
MLA Handbook (7th Edition):
Miao, Yu. “CO₂ Reduction in Microscale-Based Corona Reactor : Experiments and Modeling.” 2016. Web. 02 Mar 2021.
Vancouver:
Miao Y. CO₂ Reduction in Microscale-Based Corona Reactor : Experiments and Modeling. [Internet] [Doctoral dissertation]. Oregon State University; 2016. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1957/59109.
Council of Science Editors:
Miao Y. CO₂ Reduction in Microscale-Based Corona Reactor : Experiments and Modeling. [Doctoral Dissertation]. Oregon State University; 2016. Available from: http://hdl.handle.net/1957/59109
29.
Mervine, Evelyn M.
Determining timescales of natural carbonation of peridotite in the Samail Ophiolite, Sultanate of Oman.
Degree: 2012, MIT and Woods Hole Oceanographic Institution
URL: http://hdl.handle.net/1912/5279
► Determining timescales of the formation and preservation of carbonate alteration products in mantle peridotite is important in order to better understand the role of this…
(more)
▼ Determining timescales of the formation and preservation of carbonate alteration
products in mantle peridotite is important in order to better understand the role of this
potentially important sink in the global carbon cycle and also to evaluate the feasibility of
using artificially-enhanced, in situ formation of carbonates in peridotite to mitigate the
buildup of anthropogenic CO2 emissions in the atmosphere. Timescales of natural
carbonation of peridotite were investigated in the mantle layer of the Samail Ophiolite,
Sultanate of Oman. Rates of ongoing, low-temperature CO2 uptake were estimated
through 14C and 230Th dating of carbonate alteration products. Approximately 1-3 x 106
kg CO2/yr is sequestered in Ca-rich surface travertines and approximately 107 kg CO2/yr
is sequestered in Mg-rich carbonate veins. Rates of CO2 removal were estimated through
calculation of maximum erosion rates from cosmogenic 3He measurements in partiallyserpentinized
peridotite bedrock associated with carbonate alteration products. Maximum
erosion rates for serpentinized peridotite bedrock are ~5 to 180 m/Myr (average: ~40
m/Myr), which removes at most 105-106 kg CO2/yr through erosion of Mg-rich carbonate
veins.
Subjects/Keywords: Carbon dioxide sinks; Peridotite
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APA (6th Edition):
Mervine, E. M. (2012). Determining timescales of natural carbonation of peridotite in the Samail Ophiolite, Sultanate of Oman. (Thesis). MIT and Woods Hole Oceanographic Institution. Retrieved from http://hdl.handle.net/1912/5279
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mervine, Evelyn M. “Determining timescales of natural carbonation of peridotite in the Samail Ophiolite, Sultanate of Oman.” 2012. Thesis, MIT and Woods Hole Oceanographic Institution. Accessed March 02, 2021.
http://hdl.handle.net/1912/5279.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mervine, Evelyn M. “Determining timescales of natural carbonation of peridotite in the Samail Ophiolite, Sultanate of Oman.” 2012. Web. 02 Mar 2021.
Vancouver:
Mervine EM. Determining timescales of natural carbonation of peridotite in the Samail Ophiolite, Sultanate of Oman. [Internet] [Thesis]. MIT and Woods Hole Oceanographic Institution; 2012. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1912/5279.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mervine EM. Determining timescales of natural carbonation of peridotite in the Samail Ophiolite, Sultanate of Oman. [Thesis]. MIT and Woods Hole Oceanographic Institution; 2012. Available from: http://hdl.handle.net/1912/5279
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
30.
Follett, Christopher L.
Heterogeneous reservoirs in the marine carbon cycle.
Degree: 2014, MIT and Woods Hole Oceanographic Institution
URL: http://hdl.handle.net/1912/6751
► Understanding the fate of primary production in the ocean is a challenging task because once produced, organic material is oxidized over timescales which range from…
(more)
▼ Understanding the fate of primary production in the ocean is a challenging task because
once produced, organic material is oxidized over timescales which range from
minutes, to millions of years. This timescale diversity is matched by an equal heterogeneity
in both the local physical and chemical environment. In this thesis we explore
the relationship between the distinct reservoirs of organic carbon in the ocean and
their underlying complexity. First, we show how the heterogeneity of portions of
the carbon cycle can be packaged in terms of age structured models and their accompanying
age and rate distributions. We further relate the moments of the rate
distributions to bulk reservoir properties like average age and
flux. Explicit relationships
are then derived for the specific case of a single turnover time and a lognormal
distribution. We apply these ideas to the problem of dissolved organic carbon (DOC)
cycling in the ocean. Current models of bulk concentration and isotope data suggest
a microbially sourced DOC reservoir consisting of two components. A nearly homogeneous
background component with a long turnover time (> 6000 years) is joined by
a component of fast turnover time (~1 year) and equal concentration in the surface
ocean. We confirm the presence of isotopically enriched, modern DOC co-cycling
with an isotopically depleted older fraction in the upper ocean. However, our results
show that up to 30% of the deep DOC reservoir is modern and supported by a 1 Pg
per year carbon
flux, ten times higher than inferred from bulk isotope measurements.
Isotopically depleted material turns over at an apparent time scale of 30;000 years,
far slower than indicated by bulk isotope measurements. These results are consistent
with global DOC measurements and explain both the
fluctuations in deep DOC
concentration and the anomalous radiocarbon values of DOC in the Southern Ocean.
Finally, the thesis explores methods for determining the validity of diffusion limitation
as the mechanism behind the power-law slowdown in organic remineralization in
sediment. We find that diffusion limitation connects the decay behavior of organic
material to the correlations found between mineral surface area and organic matter
content in sediments.
Subjects/Keywords: Organic compounds; Carbon dioxide content
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APA (6th Edition):
Follett, C. L. (2014). Heterogeneous reservoirs in the marine carbon cycle. (Thesis). MIT and Woods Hole Oceanographic Institution. Retrieved from http://hdl.handle.net/1912/6751
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Follett, Christopher L. “Heterogeneous reservoirs in the marine carbon cycle.” 2014. Thesis, MIT and Woods Hole Oceanographic Institution. Accessed March 02, 2021.
http://hdl.handle.net/1912/6751.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Follett, Christopher L. “Heterogeneous reservoirs in the marine carbon cycle.” 2014. Web. 02 Mar 2021.
Vancouver:
Follett CL. Heterogeneous reservoirs in the marine carbon cycle. [Internet] [Thesis]. MIT and Woods Hole Oceanographic Institution; 2014. [cited 2021 Mar 02].
Available from: http://hdl.handle.net/1912/6751.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Follett CL. Heterogeneous reservoirs in the marine carbon cycle. [Thesis]. MIT and Woods Hole Oceanographic Institution; 2014. Available from: http://hdl.handle.net/1912/6751
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
◁ [1] [2] [3] [4] [5] … [92] ▶
. 
Open Access Theses and Dissertations
