You searched for subject:( NOx).
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Georgia Tech
1.
Li, Jianfeng.
Anthropogenic and natural nitrogen oxides emissions over the United States: Comprehensive evaluations and implications for surface ozone prediction.
Degree: PhD, Earth and Atmospheric Sciences, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/62675 
► Nitrogen oxides (NOx = NO + NO2) play a crucial role in the formation of ozone and has significant impacts on the production of secondary…
(more)
▼ Nitrogen oxides (
NOx = NO + NO2) play a crucial role in the formation of ozone and has significant impacts on the production of secondary organic and inorganic aerosols, thus affecting human health, global radiation budget, and climate. Accurate knowledge of
NOx emissions is essential for relevant scientific research and air pollution control policies. This thesis evaluates current estimates of anthropogenic and natural
NOx emissions over the United States and improves model’s prediction of surface ozone concentrations by using a 3-D Regional chEmistry and trAnsport Model (REAM) and various types of observations and investigate the impact of thunderstorms on surface
NOx and O3 concentrations.
The diurnal cycle of NO2 is a function of emissions, advection, deposition, vertical mixing, and chemistry. Its observations, therefore, provide useful constraints in our understanding of these factors. The REAM simulated diurnal cycles are evaluated by using the DISCOVER-AQ campaign measurements, EPA Air Quality System (AQS) observations, and OMI and GOME-2A tropospheric vertical column densities (TVCDs) products in July 2011 over the Baltimore-Washington region. The model simulations are in reasonably good agreement with the observations except that PANDORA measured NO2 TVCD show much less variation in the early morning and late afternoon than simulated in the model. High resolution (4 km in the horizontal) model simulations are also performed to examine the effects of emission distributions. The overestimation of NO2 concentrations from the 4-km REAM simulation in contrast to the well reproduction of observations by the 36-km REAM suggests that the 2011 National Emission Inventory (NEI2011) provide a good estimate of
NOx emissions at the 36-km scale but can’t resolve
NOx emission distributions at the 4-km resolution. By analyzing model simulations with the observations, the thesis shows that the diurnal emission profile of
NOx is different over the weekend from the weekdays and that weekend emissions are about 1/3 lower than weekdays. Observed ozone concentrations can be used to evaluate
NOx and volatile organic compound (VOC) emissions by using their relationships with ozone concentrations. The thesis shows that the time when ozone reaches its daily maximum (peak time) is also related to
NOx and VOC emissions. Through model sensitivity analyses of REAM in July 2011 over the contiguous United States (CONUS), it is found that ozone peak values are more sensitive to
NOx emissions while ozone peak time is more sensitive to VOC emissions in the eastern United States. By such relationships and the comparison between observations and model results, we find that the underestimation of soil
NOx emissions leads to a low bias of simulated ozone peak value in the South, while the overestimation of biogenic isoprene emissions results in earlier than observed ozone peak time in the Central, South and Southeast regions. The simulated formaldehyde columns, which are higher than satellite measurements, confirm the latter. We illustrate the…
Advisors/Committee Members: Wang, Yuhang (advisor), Huey, Greg (committee member), Weber, Rodney (committee member), Ng, Nga Lee (committee member), Kaiser, Jennifer (committee member).
Subjects/Keywords: NOx ozone
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APA (6th Edition):
Li, J. (2019). Anthropogenic and natural nitrogen oxides emissions over the United States: Comprehensive evaluations and implications for surface ozone prediction. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62675
Chicago Manual of Style (16th Edition):
Li, Jianfeng. “Anthropogenic and natural nitrogen oxides emissions over the United States: Comprehensive evaluations and implications for surface ozone prediction.” 2019. Doctoral Dissertation, Georgia Tech. Accessed March 01, 2021.
http://hdl.handle.net/1853/62675.
MLA Handbook (7th Edition):
Li, Jianfeng. “Anthropogenic and natural nitrogen oxides emissions over the United States: Comprehensive evaluations and implications for surface ozone prediction.” 2019. Web. 01 Mar 2021.
Vancouver:
Li J. Anthropogenic and natural nitrogen oxides emissions over the United States: Comprehensive evaluations and implications for surface ozone prediction. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1853/62675.
Council of Science Editors:
Li J. Anthropogenic and natural nitrogen oxides emissions over the United States: Comprehensive evaluations and implications for surface ozone prediction. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62675
University of Houston
2.
Perng, Charles C. Y.
Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts.
Degree: MS, Chemical Engineering, 2014, University of Houston
URL: http://hdl.handle.net/10657/1561
► Lean NOx (NO + NO2) reduction was carried out using rapid periodic injection of C3H6 over a NOx storage and reduction (NSR) monolith catalyst containing…
(more)
▼ Lean
NOx (NO + NO2) reduction was carried out using rapid periodic injection of C3H6 over a
NOx storage and reduction (NSR) monolith catalyst containing Pt/Rh/BaO/CeO2/Al2O3. The effects of injection speed, feed temperature, rich phase composition, lean phase duration, and feed concentration of CO2 were systematically studied to highlight distinct performance characteristics at faster injection frequencies. Increased
NOx and C3H6 conversions were achieved using high frequency injection. The detrimental effects of barium nitrate decomposition at high temperatures and barium carbonate formation were also found to be less significant using rapid pulsing. In addition, a prolonged approach to cyclic steady state was observed for high frequency operation. The results are indicative of a qualitative mechanistic change and suggest the generation of reactive “HCxNyOz” intermediate species that enable improved performance over traditional NSR cycling.
Advisors/Committee Members: Harold, Michael P. (advisor), Epling, William S. (committee member), Franchek, Matthew A. (committee member).
Subjects/Keywords: NOx; Platinum; Reduction; NOx storage; NOx reduction; Propylene; Periodic operation
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APA (6th Edition):
Perng, C. C. Y. (2014). Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts. (Masters Thesis). University of Houston. Retrieved from http://hdl.handle.net/10657/1561
Chicago Manual of Style (16th Edition):
Perng, Charles C Y. “Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts.” 2014. Masters Thesis, University of Houston. Accessed March 01, 2021.
http://hdl.handle.net/10657/1561.
MLA Handbook (7th Edition):
Perng, Charles C Y. “Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts.” 2014. Web. 01 Mar 2021.
Vancouver:
Perng CCY. Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts. [Internet] [Masters thesis]. University of Houston; 2014. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10657/1561.
Council of Science Editors:
Perng CCY. Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts. [Masters Thesis]. University of Houston; 2014. Available from: http://hdl.handle.net/10657/1561
University of California – Berkeley
3.
Weiss, Brian M.
Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces.
Degree: Chemical Engineering, 2010, University of California – Berkeley
URL: http://www.escholarship.org/uc/item/6s62946g
► NO oxidation catalysts are used in conjunction with NOx adsorbents to remove toxic nitrogen oxides from combustion effluents that lack CO and residual hydrocarbons as…
(more)
▼ NO oxidation catalysts are used in conjunction with NOx adsorbents to remove toxic nitrogen oxides from combustion effluents that lack CO and residual hydrocarbons as reductants. Efficient NOx trapping strategies require detailed knowledge of the reaction mechanism and the structural requirements for NO oxidation and for NOx adsorption, which are investigated here by kinetic, isotopic, and spectroscopic methods. NO oxidation rates on Pt, PdO, RhO2, and Co3O4 catalysts increase linearly with O2 and NO pressures and are inhibited by NO2, consistent with a kinetically-relevant NO oxidation step that requires the reaction of O2 with vacancies (*) on active sites nearly saturated with oxygen atoms (O*). Equilibrated reactions between catalyst surfaces and NO and NO2 molecules establish the concentration of oxygen vacancies during NO oxidation. Measurements of 16O2-18O2 exchange rates are used to confirm and to further investigate the O¬2 activation steps proposed for NO oxidation. NO oxidation rates on all catalysts are markedly higher on large metal and oxide clusters that bind oxygen more weakly than small clusters; consequently, oxygen vacancies become more abundant as cluster size increases. Both RhO2 and Co3O4 undergo one-electron reductions to intermediate oxidation states (Rh2O3 and CoO) when vacancies form during NO oxidation, which allows both Rh and Co oxides to effectively catalyze NO oxidation.The pervasive NO2 inhibition of NO oxidation turnovers leads to synergistic effects between NOx adsorbents and NO oxidation catalysts. NO oxidation rates are much higher when NO2 adsorption sites are present to bind NO2 as it forms on catalyst sites, and NO oxidation rates depend critically on the rate of NO2 adsorption on oxide substrates.NOx adsorption on BaO-containing solids leads to nitrites (NO2-) and nitrates (NO3-). The formation of nitrites on BaO/Al2O3 requires vicinal co-adsorption of NO and NO2 to displace carbonates that form during exposure to CO2 in combustion effluent. NO and NO2 bind rapidly as nitrite, but NOx uptakes as nitrite are limited in CO2-rich streams by thermodynamics that result in most binding sites being occupied with carbonate at high CO2/NOx ratios. Nitrates are more stable, and their formation is required to achieve large NOx uptakes from combustion effluent. The conversion of nitrites to nitrates, however, requires N2O4 molecules as oxidants that form slowly by non-activated homogeneous NO2 dimerization reactions, consistent with nitrate formation rates that increase with (NO2)2 and are independent of adsorbate coverage. Pt clusters present in close proximity to nitrite-saturated BaO domains provide a catalytic route for the formation of N2O4 that reacts subsequently with nitrites. These elementary steps lead to nitrate formation rates on BaO/Pt/Al2O3 that are inhibited by NO and are proportional to NO2 pressure and the coverage of unreacted nitrites. The results herein identify the physical limitations of oxidation catalysts and NOx adsorbents that are used for NOx trapping and provide…
Subjects/Keywords: Chemical Engineering; Chemistry; Lean NOx traps; NO oxidation catalysis; NOx adsorption; NOx storage-reduction
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APA (6th Edition):
Weiss, B. M. (2010). Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/6s62946g
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):
Weiss, Brian M. “Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces.” 2010. Thesis, University of California – Berkeley. Accessed March 01, 2021.
http://www.escholarship.org/uc/item/6s62946g.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Weiss, Brian M. “Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces.” 2010. Web. 01 Mar 2021.
Vancouver:
Weiss BM. Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces. [Internet] [Thesis]. University of California – Berkeley; 2010. [cited 2021 Mar 01].
Available from: http://www.escholarship.org/uc/item/6s62946g.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Weiss BM. Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces. [Thesis]. University of California – Berkeley; 2010. Available from: http://www.escholarship.org/uc/item/6s62946g
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
4.
Viswanathan K R.
Selective catalytic reduction of nox on new catalytic
systems;.
Degree: Selective catalytic reduction of nox on new catalytic
systems, 2015, Anna University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/33724
► Air pollution is the major part of overall atmospheric pollution and newlinemotor vehicle emissions usually constitute the most significant source for air newlinepollution In cities…
(more)
▼ Air pollution is the major part of overall
atmospheric pollution and newlinemotor vehicle emissions usually
constitute the most significant source for air newlinepollution In
cities across the globe the personal automobile is the single
newlinelargest polluter as emissions from a billion vehicles on the
road add up to newlineplanetwide problem Environmental pollution by
engine exhausts has newlinebecome more and more serious problem
especially with respect to nitrogen newlineoxidesNOx Since the
success in reducing the pollutant emission is newlineindispensable
for vehicles to survive great efforts have been devoted to
newlinedevelop efficient catalysts Important chemical pollutants
emitted by land newlinevehicles are carbon monoxide CO sulphur
dioxide SO2 nitrogen oxides newlineNOxand total suspended
particulates TSP newline newline newline
Reference p.124-136
Advisors/Committee Members: Periasamy VM.
Subjects/Keywords: catalytic reduction; mechanical engineering; nox
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APA (6th Edition):
R, V. K. (2015). Selective catalytic reduction of nox on new catalytic
systems;. (Thesis). Anna University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/33724
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):
R, Viswanathan K. “Selective catalytic reduction of nox on new catalytic
systems;.” 2015. Thesis, Anna University. Accessed March 01, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/33724.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
R, Viswanathan K. “Selective catalytic reduction of nox on new catalytic
systems;.” 2015. Web. 01 Mar 2021.
Vancouver:
R VK. Selective catalytic reduction of nox on new catalytic
systems;. [Internet] [Thesis]. Anna University; 2015. [cited 2021 Mar 01].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/33724.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
R VK. Selective catalytic reduction of nox on new catalytic
systems;. [Thesis]. Anna University; 2015. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/33724
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
5.
Bandura, Ryan Alexander.
Simple Zero Dimensional Quasi-predictive Thermodynamic Simulation for Prediction of NOx for Diesel Combustion.
Degree: MS, Mechanical Engineering, 2017, Texas A&M University
URL: http://hdl.handle.net/1969.1/161590
► Computational fluid dynamics (CFD) is now a ubiquitous computational tool for engine design and analysis. It is often necessary to provide well-known initial cycle conditions…
(more)
▼ Computational fluid dynamics (CFD) is now a ubiquitous computational tool for engine design and analysis. It is often necessary to provide well-known initial cycle conditions to commence the CFD computations. Such initial conditions can be provided by experimental data. To create an opportunity to computationally study engine conditions where experimental data are not available, a zero-dimensional quasi-predictive thermodynamic simulation is developed that uses a well-established spray model to predict rate of heat release and calculated burned gas composition and temperature to predict nitric oxide (NO) concentration. This thesis details the thermodynamic simulation for diesel engine operating conditions. The goal is to produce an algorithm that is capable of predicting NO emissions as well as performance characteristics such as mean effective pressure (MEP). The simulation uses general conservation of mass and energy approaches to model intake, compression, and exhaust. Rate of heat release prediction is based on an existing spray model to predict how fuel concentrations within the spray jet change with penetration. Rate of heat release provides predicted cylinder pressure, which is then validated against experimental pressure data under known operating conditions. An equilibrium mechanism is used to determine burned gas composition which, along with burned gas temperature, can be used for prediction of NO in the cylinder. NO is predicted using the extended Zeldovich mechanism. This mechanism is highly sensitive to temperature, and it is therefore important to accurately predict cylinder gas temperature to obtain correct NO values. iii The simulation focuses on single fuel injection events, but some multiple injection events are investigated, and improvements to the model to better handle these cases are suggested.
Advisors/Committee Members: Jacobs, Timothy (advisor), Caton, Jerald (committee member), Karpetis, Adonios (committee member).
Subjects/Keywords: Diesel; combustion; NOx; CFD; Simulation
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APA (6th Edition):
Bandura, R. A. (2017). Simple Zero Dimensional Quasi-predictive Thermodynamic Simulation for Prediction of NOx for Diesel Combustion. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/161590
Chicago Manual of Style (16th Edition):
Bandura, Ryan Alexander. “Simple Zero Dimensional Quasi-predictive Thermodynamic Simulation for Prediction of NOx for Diesel Combustion.” 2017. Masters Thesis, Texas A&M University. Accessed March 01, 2021.
http://hdl.handle.net/1969.1/161590.
MLA Handbook (7th Edition):
Bandura, Ryan Alexander. “Simple Zero Dimensional Quasi-predictive Thermodynamic Simulation for Prediction of NOx for Diesel Combustion.” 2017. Web. 01 Mar 2021.
Vancouver:
Bandura RA. Simple Zero Dimensional Quasi-predictive Thermodynamic Simulation for Prediction of NOx for Diesel Combustion. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1969.1/161590.
Council of Science Editors:
Bandura RA. Simple Zero Dimensional Quasi-predictive Thermodynamic Simulation for Prediction of NOx for Diesel Combustion. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/161590
Open Universiteit Nederland
6.
Binsbergen, Michael J G R van.
NOx het is niet niks: onderzoeksrapport NOx in de Europese richtlijnen IPPC, NEC, WID, LCP en de koppeling met Emissiehandel, beoordeling DIE tot samenvoeging IPPC, WID & LCP en samenhang NEC
.
Degree: 2010, Open Universiteit Nederland
URL: http://hdl.handle.net/1820/2458
in deze scriptie wordt onderzoek gedaan naar de verschillen en overeenkomsten van europese richtlijnen mbt de emissie van NOx.
Subjects/Keywords: NOx;
emissie;
europese richtlijnen
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APA (6th Edition):
Binsbergen, M. J. G. R. v. (2010). NOx het is niet niks: onderzoeksrapport NOx in de Europese richtlijnen IPPC, NEC, WID, LCP en de koppeling met Emissiehandel, beoordeling DIE tot samenvoeging IPPC, WID & LCP en samenhang NEC
. (Masters Thesis). Open Universiteit Nederland. Retrieved from http://hdl.handle.net/1820/2458
Chicago Manual of Style (16th Edition):
Binsbergen, Michael J G R van. “NOx het is niet niks: onderzoeksrapport NOx in de Europese richtlijnen IPPC, NEC, WID, LCP en de koppeling met Emissiehandel, beoordeling DIE tot samenvoeging IPPC, WID & LCP en samenhang NEC
.” 2010. Masters Thesis, Open Universiteit Nederland. Accessed March 01, 2021.
http://hdl.handle.net/1820/2458.
MLA Handbook (7th Edition):
Binsbergen, Michael J G R van. “NOx het is niet niks: onderzoeksrapport NOx in de Europese richtlijnen IPPC, NEC, WID, LCP en de koppeling met Emissiehandel, beoordeling DIE tot samenvoeging IPPC, WID & LCP en samenhang NEC
.” 2010. Web. 01 Mar 2021.
Vancouver:
Binsbergen MJGRv. NOx het is niet niks: onderzoeksrapport NOx in de Europese richtlijnen IPPC, NEC, WID, LCP en de koppeling met Emissiehandel, beoordeling DIE tot samenvoeging IPPC, WID & LCP en samenhang NEC
. [Internet] [Masters thesis]. Open Universiteit Nederland; 2010. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1820/2458.
Council of Science Editors:
Binsbergen MJGRv. NOx het is niet niks: onderzoeksrapport NOx in de Europese richtlijnen IPPC, NEC, WID, LCP en de koppeling met Emissiehandel, beoordeling DIE tot samenvoeging IPPC, WID & LCP en samenhang NEC
. [Masters Thesis]. Open Universiteit Nederland; 2010. Available from: http://hdl.handle.net/1820/2458
University of Surrey
7.
Yates, Anthony John.
LCA, clean-up technologies and abatement of gaseous pollutant emissions from chemical processing plant.
Degree: Thesis (Eng.D.), 1997, University of Surrey
URL: http://epubs.surrey.ac.uk/856871/
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388784
► This Doctorate study has been split into two distinct phases with two separate sponsoring companies. The first 27 months were spent with British Nuclear Fuels…
(more)
▼ This Doctorate study has been split into two distinct phases with two separate sponsoring companies. The first 27 months were spent with British Nuclear Fuels plc developing a End-of-Pipe technology for abatement of NOx emissions. The second phase of the Doctorate was concerned with developing Life Cycle Assessment as a means of predicting Environmental Burdens for End-of-Pipe technologies. The common theme linking the two projects is the comparison of End-of-Pipe, Clean-up technologies with Clean Technologies in the chemical processing industry. The research has been able to show that adsorption onto zeolite is suitable technology for removal of NOx and that compared to most other NOx abatement technologies offers a very low Environmental Burden. Only peroxide scrubbing has the potential of a lower Environmental Burden. Both technologies exhibit negative Environmental Burdens; i.e. by reusing the NOx they eliminate Environmental Burdens elsewhere in the life cycle. Such predictions have been possible through application of Life Cycle principles to the technology comparisons. Whilst the second phase of the research does develop definitive answers for the specific examples considered, the main aim of the work is to show how Life Cycle principles can be applied to End-of-Pipe technologies such that accurate comparisons between the Environmental Impacts of each technology can be made. The work shows how current BPEO thinking could be replaced by a Life Cycle based approach to ensure that pollution abatement projects actually do minimise Environmental Burden as a whole rather than shifting the Burden from one part of the life cycle to another.
Subjects/Keywords: 628.53; NOx
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APA (6th Edition):
Yates, A. J. (1997). LCA, clean-up technologies and abatement of gaseous pollutant emissions from chemical processing plant. (Doctoral Dissertation). University of Surrey. Retrieved from http://epubs.surrey.ac.uk/856871/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388784
Chicago Manual of Style (16th Edition):
Yates, Anthony John. “LCA, clean-up technologies and abatement of gaseous pollutant emissions from chemical processing plant.” 1997. Doctoral Dissertation, University of Surrey. Accessed March 01, 2021.
http://epubs.surrey.ac.uk/856871/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388784.
MLA Handbook (7th Edition):
Yates, Anthony John. “LCA, clean-up technologies and abatement of gaseous pollutant emissions from chemical processing plant.” 1997. Web. 01 Mar 2021.
Vancouver:
Yates AJ. LCA, clean-up technologies and abatement of gaseous pollutant emissions from chemical processing plant. [Internet] [Doctoral dissertation]. University of Surrey; 1997. [cited 2021 Mar 01].
Available from: http://epubs.surrey.ac.uk/856871/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388784.
Council of Science Editors:
Yates AJ. LCA, clean-up technologies and abatement of gaseous pollutant emissions from chemical processing plant. [Doctoral Dissertation]. University of Surrey; 1997. Available from: http://epubs.surrey.ac.uk/856871/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388784
University of Miami
8.
Cavallin, Lucas E.
The Role of PDGF AND Rac1-induced Oxidative Signaling in the Viral Oncogenesis of Kaposi's Sarcoma.
Degree: PhD, Microbiology and Immunology (Medicine), 2010, University of Miami
URL: https://scholarlyrepository.miami.edu/oa_dissertations/441
► Kaposi's sarcoma (KS), caused by the oncogenic Kaposi's sarcoma herpesvirus (KSHV), is an angiogenic tumor characterized by intense angiogenesis, inflammation and proliferation of KSHV-infected…
(more)
▼ Kaposi's sarcoma (KS), caused by the oncogenic Kaposi's sarcoma herpesvirus (KSHV), is an angiogenic tumor characterized by intense angiogenesis, inflammation and proliferation of KSHV-infected spindle cells. We describe the characterization of a mouse model of KS by transfection of a KSHV bacterial artificial chromosome (KSHVBac36) into mouse bone marrow endothelial-lineage cells which generated a cell (mECK36) that forms KS-like tumors in mice. Our results define mECK36 as a biologically sensitive animal model of KSHV-dependent KS with the following characteristics: (1) the pathological phenotype is a consequence of KSHV gene expression in normal progenitor cells subjected to in vivo growth conditions, (2) the histopathologic phenotype of the tumors resembles KS lesions, and (3) the model is suitable for analysis of vGPCR-driven tumorigenesis in the context of the whole KSHV genome. The mechanism by which vGPCR promotes tumorigenesis is not fully understood. The characterization of a Rac1 transgenic mouse model that produces KS-like lesions that highly resemble human KS has helped us to identify the potential role of Rac1, which is activated by vGPCR, in the pathogenesis of KS. The results from the RacCA transgenic mouse suggest that viral and host genes triggering Rac1 and ROS production may play an important role in KS tumorigenesis. We set out to determine how vGPCR physiologically activates Rac1 in KSHV-infected cells in the KS model mECK36. We found that KSHV oncogenesis in mECK36 is promoted by vGPCR activation of a paracrine oncogenic mechanism through PDGF-BB, which requires a Rac1- and ROS-mediated loop, leading to STAT3 transcriptional activation of c-Myc, VEGF and KSHV latent viral gene expression. We also found that the latency-associated nuclear antigen (LANA) upregulates the PDGFR in vivo, priming latently-infected cells to the PDGF signaling pathway. This oncogenic mechanism can be targeted with the antioxidant N-acetylcysteine (NAC) and FDA-approved PDGF receptor inhibitors to control KSHV-induced tumorigenesis. Our results highlight a ROS-dependent axis whereby Rac1 activating oncogenes and inflammatory signaling drive paracrine stimulation of neoplastic growth and angiogenesis in neighboring cells, defining this axis and its components as attractive anti-tumor targets in KS pathogenesis.
Advisors/Committee Members: Eli Gilboa, Edward W. Harhaj, Jaime R. Merchan, Kurt Schesser, Enrique A. Mesri, Elliott D. Kieff.
Subjects/Keywords: NOX; NADPH Oxidase; Herpesvirus; HHV8
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APA (6th Edition):
Cavallin, L. E. (2010). The Role of PDGF AND Rac1-induced Oxidative Signaling in the Viral Oncogenesis of Kaposi's Sarcoma. (Doctoral Dissertation). University of Miami. Retrieved from https://scholarlyrepository.miami.edu/oa_dissertations/441
Chicago Manual of Style (16th Edition):
Cavallin, Lucas E. “The Role of PDGF AND Rac1-induced Oxidative Signaling in the Viral Oncogenesis of Kaposi's Sarcoma.” 2010. Doctoral Dissertation, University of Miami. Accessed March 01, 2021.
https://scholarlyrepository.miami.edu/oa_dissertations/441.
MLA Handbook (7th Edition):
Cavallin, Lucas E. “The Role of PDGF AND Rac1-induced Oxidative Signaling in the Viral Oncogenesis of Kaposi's Sarcoma.” 2010. Web. 01 Mar 2021.
Vancouver:
Cavallin LE. The Role of PDGF AND Rac1-induced Oxidative Signaling in the Viral Oncogenesis of Kaposi's Sarcoma. [Internet] [Doctoral dissertation]. University of Miami; 2010. [cited 2021 Mar 01].
Available from: https://scholarlyrepository.miami.edu/oa_dissertations/441.
Council of Science Editors:
Cavallin LE. The Role of PDGF AND Rac1-induced Oxidative Signaling in the Viral Oncogenesis of Kaposi's Sarcoma. [Doctoral Dissertation]. University of Miami; 2010. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/441
University of Houston
9.
Liu, Yi 1986-.
NOx Removal by LNT-SCR Dual-layer Catalysts.
Degree: PhD, Chemical Engineering, 2012, University of Houston
URL: http://hdl.handle.net/10657/789
► The increasingly strict emission standards have driven the progress of NOx storage and reduction (NSR) technology. NOx is stored in a lean NOx trap (LNT)…
(more)
▼ The increasingly strict emission standards have driven the progress of
NOx storage and reduction (NSR) technology.
NOx is stored in a lean
NOx trap (LNT) catalyst during fuel-lean mode and reduced to N2 during fuel-rich mode.
First, we investigated the impact of ceria on NSR in an Pt/Ce LNT catalyst. The physisorbed oxygen over the ceria-containing LNT catalyst led to a spatio-temporal temperature rise in the monolith upstream after the cyclic introduction of H2/CO to a pre-oxidized catalyst. The stored oxygen over ceria enhanced NO storage by in-situ NO2 formation, while it competed with NO2 for storage sites. During the
NOx reduction over the Pt/Ceria, the Pt surface purgation was the first step and the oxygen reduction preceded the
NOx reduction.
Second, we studied the NSR by dual-layer catalysts consisting of a selective catalytic reduction (SCR) catalyst layer on top of a LNT catalyst. During periodic switching between lean and rich feeds, the LNT layer reduced
NOx to N2 and NH3. The SCR layer trapped the latter leading to additional
NOx reduction.
The dual-layer catalysts exhibited high N2 selectivity and low NH3 selectivity over the temperature range of 150-400 ºC. The
NOx conversion was incomplete due to undesired NH3 oxidation. The dual-layer catalyst has a higher
NOx conversion and N2 selectivity than the LNT catalyst when H2O and CO2 were present in the feed.
Ceria was used to adjust the dual-layer catalyst performance. The ceria addition increased
NOx storage capacity, promoted hydrothermal durability and mitigated CO poisoning. However, ceria decreased the high-temperature
NOx conversion by promoting NH3 oxidation. Ceria zoning led to the highest
NOx reduction for both low- and high- temperatures due to the beneficial interaction of ceria and H2.
The impact of catalyst design and operation strategy was evaluated. The low-temperature
NOx conversion of an aged dual-layer catalyst was increased by a high SCR catalyst loading. The ratio of lean to rich feed duration and the total cycle time were optimized to improve the
NOx conversion. The results suggest the dual-layer catalyst could be used to reduce precious metal loading and improve the fuel economy.
Advisors/Committee Members: Luss, Dan (advisor), Harold, Michael P. (advisor), Balakotaiah, Vemuri (committee member), Chellam, Shankar (committee member), Jacobson, Allan J. (committee member).
Subjects/Keywords: NOx; Catalysts; Lean NOx traps; NOx storage; NOx reduction; Selective catalytic reduction (SCR); Dual-layer catalysts; Chemical engineering
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APA (6th Edition):
Liu, Y. 1. (2012). NOx Removal by LNT-SCR Dual-layer Catalysts. (Doctoral Dissertation). University of Houston. Retrieved from http://hdl.handle.net/10657/789
Chicago Manual of Style (16th Edition):
Liu, Yi 1986-. “NOx Removal by LNT-SCR Dual-layer Catalysts.” 2012. Doctoral Dissertation, University of Houston. Accessed March 01, 2021.
http://hdl.handle.net/10657/789.
MLA Handbook (7th Edition):
Liu, Yi 1986-. “NOx Removal by LNT-SCR Dual-layer Catalysts.” 2012. Web. 01 Mar 2021.
Vancouver:
Liu Y1. NOx Removal by LNT-SCR Dual-layer Catalysts. [Internet] [Doctoral dissertation]. University of Houston; 2012. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10657/789.
Council of Science Editors:
Liu Y1. NOx Removal by LNT-SCR Dual-layer Catalysts. [Doctoral Dissertation]. University of Houston; 2012. Available from: http://hdl.handle.net/10657/789
10.
Cheraki, Mohamed.
Réactivité et spectroscopie de systèmes moléculaires d'intérêt atmosphérique et biologique : Reactivity and spectroscopy of molecular systems of atmospheric and biologic interest.
Degree: Docteur es, Chimie, 2019, Université Paris-Est
URL: http://www.theses.fr/2019PESC2075
► Cette thèse a pour objectif d'étudier la photochimie et la réactivité en phase gazeuse des systèmes moléculaires de formules [S,S,X,O]q où X=N,O et q=-1, ou…
(more)
▼ Cette thèse a pour objectif d'étudier la photochimie et la réactivité en phase gazeuse des systèmes moléculaires de formules [S,S,X,O]q où X=N,O et q=-1, ou 0, ou +1 ou +2, de comprendre ces réactions à l’échelle moléculaire. Nous avons donc étudier la possibilité d’utilisation des [S,S,N,O]- comme donneur de NO dans un contexte thérapeutique. Nous avons aussi pu identifier les espèces [O,S,S,O] dans l’atmosphère de Vénus. Nous avons montré que les espèces SS-XO ont une liaison centrale de faible énergie de dissociation qui est à l’origine de leur réactivité
This thesis aims to study the photochemistry and reactivity in the gaseous phase of molecular systems which formulas are [S,S,X,O]q where X=N,O and q=-1, or 0, or +1 or +2, to understand those reactions at a molecular scale. We thus have studied the possibility of using the [S,S,N,O]- species as NO donors in therapeutic context. We also have identified the [O,S,S,O] species in Venus’ atmosphere. We have shown that the SS-XO species have a weak, low dissociation energy central bond which is origin of their reactivity
Advisors/Committee Members: Hochlaf, Majdi (thesis director).
Subjects/Keywords: S-Nitrosothiols; Spectroscopie; Réactivité; NOx; S-Nistrosothiols; Spectroscopy; Reactivity; NOx
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APA (6th Edition):
Cheraki, M. (2019). Réactivité et spectroscopie de systèmes moléculaires d'intérêt atmosphérique et biologique : Reactivity and spectroscopy of molecular systems of atmospheric and biologic interest. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2019PESC2075
Chicago Manual of Style (16th Edition):
Cheraki, Mohamed. “Réactivité et spectroscopie de systèmes moléculaires d'intérêt atmosphérique et biologique : Reactivity and spectroscopy of molecular systems of atmospheric and biologic interest.” 2019. Doctoral Dissertation, Université Paris-Est. Accessed March 01, 2021.
http://www.theses.fr/2019PESC2075.
MLA Handbook (7th Edition):
Cheraki, Mohamed. “Réactivité et spectroscopie de systèmes moléculaires d'intérêt atmosphérique et biologique : Reactivity and spectroscopy of molecular systems of atmospheric and biologic interest.” 2019. Web. 01 Mar 2021.
Vancouver:
Cheraki M. Réactivité et spectroscopie de systèmes moléculaires d'intérêt atmosphérique et biologique : Reactivity and spectroscopy of molecular systems of atmospheric and biologic interest. [Internet] [Doctoral dissertation]. Université Paris-Est; 2019. [cited 2021 Mar 01].
Available from: http://www.theses.fr/2019PESC2075.
Council of Science Editors:
Cheraki M. Réactivité et spectroscopie de systèmes moléculaires d'intérêt atmosphérique et biologique : Reactivity and spectroscopy of molecular systems of atmospheric and biologic interest. [Doctoral Dissertation]. Université Paris-Est; 2019. Available from: http://www.theses.fr/2019PESC2075
University of Houston
11.
Zheng, Yang.
Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control.
Degree: PhD, Chemical Engineering, 2015, University of Houston
URL: http://hdl.handle.net/10657/5451
► The increasingly stringent both greenhouse gas (GHG) and tailpipe NOx emission standards have driven the continuous improvement of commercial deNOx technologies, NOx reduction & storage…
(more)
▼ The increasingly stringent both greenhouse gas (GHG) and tailpipe
NOx emission standards have driven the continuous improvement of commercial deNOx technologies,
NOx reduction & storage (NSR, also referred to as lean
NOx trap (LNT)) and selective catalytic reduction (SCR) technologies. This dissertation conducts applied and fundamental studies of coupled LNT-SCR dual-layer catalysts with the aim of expanding the operating temperature window of a conventional NSR system at lower cost. This is accomplished by a systems approach to identify the influencing factors such as catalyst composition and architecture, types of reducing agents, operating and regeneration strategies, as well as synergistic interactions between the LNT and SCR. We start with performance evaluation of dual-layer catalysts under different regeneration conditions such as H2 alone, CO/H2 mixture and a simulated diesel exhaust containing the CO/H2/C3H6 mixture. Spatial analyses of NH3 yield and
NOx conversion along the LNT monolith identify the upstream zone as major NH3 generator and
NOx reducer, especially at temperatures exceeding 300 °C. Zoning of either or both the SCR and LNT having a dual-layer structure enables an increase in the low-temperature (200-250 °C)
NOx conversion, and minimizes the high temperature (300-400 °C) conversion loss caused by the SCR diffusion resistance and undesired NH3 oxidation by the LNT. The hydrocarbon (HC) reductant leads to an alternative LNT-SCR synergy to classical NH3-pathway; a LNT-assisted HC-SCR pathway. The LNT promotes the formation of partially oxidized HC intermediates during the rich purge which are otherwise difficult to be generated by the Cu-zeolite layer at low temperatures. These activated intermediates can be captured and utilized by the SCR catalyst via HC-SCR during the ensuing lean phase. This pathway plays a major role at low temperatures (<= 225 °C) using the simulated diesel exhaust feed. We investigated the steady-state and transient effects of reductants (CO, H2 and C3H6) on Cu-SSZ-13 catalyzed NH3-SCR as the SCR component in the combined system is periodically exposed to a rich exhaust. The three reductants affect to different extent the NH3-SCR reactions. Propylene is most effective in promoting NO2 reduction to NO by formation of organic intermediates. CO effectively reduces nitrates to nitrites that react with NO2, releasing NO. H2 follows a similar pathway as CO but is less effective. Finally, the effects of the lean/rich cycling frequency on both LNT and combined catalysts are investigated. Rapid C3H6 pulsing into a lean exhaust steam expands the operating temperature window of a conventional NSR system in both low and high-temperature regions. The combination of rapid propylene pulsing and the dual-layer catalyst architecture achieves the highest low-temperature
NOx conversion. The working mechanisms of rapid propylene pulsing on both LNT and LNT-SCR catalysts are elucidated. Optimization of top-layer material and catalyst configuration like SCR and PGM zoning can improve system…
Advisors/Committee Members: Harold, Michael P. (advisor), Luss, Dan (committee member), Epling, William S. (committee member), Jacobson, Allan J. (committee member), Brankovic, Stanko R. (committee member).
Subjects/Keywords: Lean NOx traps; Selective catalytic reduction (SCR); NOx reduction
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APA (6th Edition):
Zheng, Y. (2015). Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control. (Doctoral Dissertation). University of Houston. Retrieved from http://hdl.handle.net/10657/5451
Chicago Manual of Style (16th Edition):
Zheng, Yang. “Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control.” 2015. Doctoral Dissertation, University of Houston. Accessed March 01, 2021.
http://hdl.handle.net/10657/5451.
MLA Handbook (7th Edition):
Zheng, Yang. “Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control.” 2015. Web. 01 Mar 2021.
Vancouver:
Zheng Y. Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control. [Internet] [Doctoral dissertation]. University of Houston; 2015. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10657/5451.
Council of Science Editors:
Zheng Y. Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control. [Doctoral Dissertation]. University of Houston; 2015. Available from: http://hdl.handle.net/10657/5451
University of Houston
12.
Dasari, Prasanna R. 1987-.
Experimental studies of NOx storage and reduction on Lean NOx Traps.
Degree: PhD, Chemical Engineering, 2013, University of Houston
URL: http://hdl.handle.net/10657/945
► Stricter emission standards have driven the research and development of several emission aftertreatment technologies like selective catalytic reduction (NH3-SCR) and lean NOX trap (LNT) technology.…
(more)
▼ Stricter emission standards have driven the research and development of several emission aftertreatment technologies like selective catalytic reduction (NH3-SCR) and lean
NOX trap (LNT) technology. On an NH3-SCR catalyst, NH3 is injected into the exhaust, which then selectively reduces
NOx to N2. During the LNT process,
NOX is stored on an alkali earth oxide during the lean phase, forming surface nitrite/nitrate species, which are then reduced to N2 over precious metals during periodic “rich” operation. A combined LNT-SCR hybrid system promises to be more cost-effective and operates by utilizing NH3 formed during the rich phase operation of LNT to reduce
NOx that breakthroughs LNT on the SCR catalyst downstream.
An experimental set-up was built to monitor the transient reactor temperatures and effluent gas concentrations. This work systematically investigated the production of NH3 on typical Pt-Rh/BaO/Al2O3 LNT monolithic catalysts during the reduction of
NOx by CO in the presence of excess water without any molecular H2 being fed to the system; under both steady-state and cyclic operation conditions. The objective was to determine the effect of various operating parameters and the involvement of intermediate species on the mechanism leading to NH3 formation and
NOx reduction. Under steady-state conditions, H2 formed by wgs reaction plays a dominant role in reducing
NOx to NH3. However, under cyclic operation conditions, hydrolysis of intermediate isocyanate species is shown to be the leading route to NH3 formation.
An extensive study of the
NOX storage mechanism and the impact of CO2 were conduced at low temperatures (< 300 ˚C). It was determined that the local minima in
NOx conversion observed at 200 ˚C, during the reduction of
NOx by H2 in the presence of CO2 was a result of the competition posed by CO2 for the two kinds of storage sites involved. Also, at 200 ˚C carbonates are relatively more stable on the Ba sites located far from Pt and were hard to replace by nitrates due to diffusion limitations. SpaciMS was employed to investigate
NOx reduction mechanism by C3H6 in LNT systems. Spatial and temporal profiles of concentrations and temperatures were developed along the catalyst length.
Advisors/Committee Members: Harold, Michael P. (advisor), Epling, William S. (committee member), Grabow, Lars C. (committee member), Franchek, Matthew A. (committee member), Jacobson, Allan J. (committee member).
Subjects/Keywords: Lean NOx traps; NH3; SpaciMS; NOx reduction; CO; H2; C3H6
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APA (6th Edition):
Dasari, P. R. 1. (2013). Experimental studies of NOx storage and reduction on Lean NOx Traps. (Doctoral Dissertation). University of Houston. Retrieved from http://hdl.handle.net/10657/945
Chicago Manual of Style (16th Edition):
Dasari, Prasanna R 1987-. “Experimental studies of NOx storage and reduction on Lean NOx Traps.” 2013. Doctoral Dissertation, University of Houston. Accessed March 01, 2021.
http://hdl.handle.net/10657/945.
MLA Handbook (7th Edition):
Dasari, Prasanna R 1987-. “Experimental studies of NOx storage and reduction on Lean NOx Traps.” 2013. Web. 01 Mar 2021.
Vancouver:
Dasari PR1. Experimental studies of NOx storage and reduction on Lean NOx Traps. [Internet] [Doctoral dissertation]. University of Houston; 2013. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10657/945.
Council of Science Editors:
Dasari PR1. Experimental studies of NOx storage and reduction on Lean NOx Traps. [Doctoral Dissertation]. University of Houston; 2013. Available from: http://hdl.handle.net/10657/945
Brno University of Technology
13.
Jedlička, Filip.
Zneškodňování spalin znečištěných NOx II: Treatment of flue gas polluted by NOx II.
Degree: 2019, Brno University of Technology
URL: http://hdl.handle.net/11012/8744
► My master’s thesis deals with the problems of NOx abatement that are included in flue gases. The accent is put on combined flue gases treatment…
(more)
▼ My master’s thesis deals with the problems of
NOx abatement that are included in flue gases. The accent is put on combined flue gases treatment throug ceramic candles, where the deposited catalyst enables
NOx reduction throug the method of selective catalytic reduction. The main aim of my master’s thesis has been the design of experimental equipment for current removal of gas pollutants (dioxins, VOC and
NOx) and fly-ash on catalitic ceramic candle. Design of experimental equipment consisted in the calculation of basic characteristics like pipe diameter, filtration chamber diameter, heater performance etc. During the design it was necessary to build pressure drop model that was split into head loss of ceramic candle and piping system. For the evaluation of experimentally measured data and for description of ongoing catalytic reaction in various operating conditions was made prediction model of catalytical filter. The last chapter deals with planned experimental testings.
Advisors/Committee Members: Dvořák, Radek (advisor), Jecha, David (referee).
Subjects/Keywords: SCR; NOx; keramické svíčky; SCR; NOx; ceramic candles
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APA (6th Edition):
Jedlička, F. (2019). Zneškodňování spalin znečištěných NOx II: Treatment of flue gas polluted by NOx II. (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/8744
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):
Jedlička, Filip. “Zneškodňování spalin znečištěných NOx II: Treatment of flue gas polluted by NOx II.” 2019. Thesis, Brno University of Technology. Accessed March 01, 2021.
http://hdl.handle.net/11012/8744.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Jedlička, Filip. “Zneškodňování spalin znečištěných NOx II: Treatment of flue gas polluted by NOx II.” 2019. Web. 01 Mar 2021.
Vancouver:
Jedlička F. Zneškodňování spalin znečištěných NOx II: Treatment of flue gas polluted by NOx II. [Internet] [Thesis]. Brno University of Technology; 2019. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/11012/8744.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Jedlička F. Zneškodňování spalin znečištěných NOx II: Treatment of flue gas polluted by NOx II. [Thesis]. Brno University of Technology; 2019. Available from: http://hdl.handle.net/11012/8744
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
14.
Madisetty, Naga Siva Sai Tarun.
Methods for Urea Crystallization Analysis: A problem in reduction of NOx for the internal combustion engines
.
Degree: Chalmers tekniska högskola / Institutionen för mekanik och maritima vetenskaper, 2020, Chalmers University of Technology
URL: http://hdl.handle.net/20.500.12380/302125
► Volvo Penta is at present looking to improve the existing engines and to develop a next generation of engines. One of the main challenges with…
(more)
▼ Volvo Penta is at present looking to improve the existing engines and to develop a next generation of engines. One of the main challenges with the present engines is the changes in the simulated exhaust flows and the backpressure developed due to the sedimentation of diesel exhaust fluids (DEF). This depends on various factors and parameters such as exhaust temperature, exhaust stream direction, DEF spray length etc. Therefore, a thorough research on this topic of DEF crystallization is useful to understand the behavior of the DEF in the exhaust pipes. The present report deals with the different phases of work involved in the methods that are developed to analyze the problem of Urea crystallization at Volvo Penta, Lundby, Göteborg.
Subjects/Keywords: Urea;
SCR catalyst;
NOx reductions;
Crystallization;
NOx;
Exhaust;
Regulations
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APA (6th Edition):
Madisetty, N. S. S. T. (2020). Methods for Urea Crystallization Analysis: A problem in reduction of NOx for the internal combustion engines
. (Thesis). Chalmers University of Technology. Retrieved from http://hdl.handle.net/20.500.12380/302125
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):
Madisetty, Naga Siva Sai Tarun. “Methods for Urea Crystallization Analysis: A problem in reduction of NOx for the internal combustion engines
.” 2020. Thesis, Chalmers University of Technology. Accessed March 01, 2021.
http://hdl.handle.net/20.500.12380/302125.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Madisetty, Naga Siva Sai Tarun. “Methods for Urea Crystallization Analysis: A problem in reduction of NOx for the internal combustion engines
.” 2020. Web. 01 Mar 2021.
Vancouver:
Madisetty NSST. Methods for Urea Crystallization Analysis: A problem in reduction of NOx for the internal combustion engines
. [Internet] [Thesis]. Chalmers University of Technology; 2020. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/20.500.12380/302125.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Madisetty NSST. Methods for Urea Crystallization Analysis: A problem in reduction of NOx for the internal combustion engines
. [Thesis]. Chalmers University of Technology; 2020. Available from: http://hdl.handle.net/20.500.12380/302125
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Kentucky
15.
Jones, Samantha.
Ceria Based Catalysts for Low Temperature NOx Storage and Release.
Degree: 2016, University of Kentucky
URL: https://uknowledge.uky.edu/chemistry_etds/67
► Model ceria catalysts were evaluated for NOx storage and desorption performance under lean conditions. Three different storage temperatures (80 °C, 120 °C, and 160 °C)…
(more)
▼ Model ceria catalysts were evaluated for NOx storage and desorption performance under lean conditions. Three different storage temperatures (80 °C, 120 °C, and 160 °C) were utilized to evaluate NOx storage. Higher temperatures resulted in higher NOx storage. It was observed that storage of platinum promoted ceria resulted in higher NOx storage compared to promotion with palladium. NOx desorption behavior of platinum promoted ceria indicated that the majority of NOx is released at high temperatures (> 350 °C), comparatively palladium promotion released more of the stored NOx at lower temperatures. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) indicated that platinum promotion results in NOx storage as thermally stabile nitrates, while palladium promotion results in NOx storage as thermally labile nitrites.
Doping ceria with trivalent rare earth oxides has been shown to improve NOx storage by generating lattice oxygen vacancies. Ceria doped with Pr, Y, La, Sm, and Nd at two different concentrations (5 and 20 mol%) and promoted with Pt were evaluated. Doping ceria with 5% Sm, Nd, and Pr improved the amount of NOx stored while the addition of Sm and La did not improve storage. Upon increasing dopant concentration, NOx storage decreased in all cases but Pr. However, increasing Pr concentration was found to increase NOx storage as well as low temperature NOx release. Ceria doped with Pr promoted with Pd increased the amount of NOx released at lower temperatures compared to Pt promotion, although palladium promotion resulted in lower storage. Similar DRIFTS spectra were obtained with Ce-Pr when promoted with Pt or Pd compared to model catalysts. Platinum promotion results in the storage of NOx at nitrates, which require high temperatures for removal. Comparatively, Pd promotion results in NOx stored at nitrites requiring lower temperatures for removal.
Ceria doped with Pr proved to be promising, although not thermally stable when exposed to high temperatures as may be seen during a DPF clean up. Therefor, stabilizing Ce-Pr catalysts with Zr were evaluated. It was found that stabilizing Ce-Pr with Zr was not found to be beneficial to the catalyst performance.
Subjects/Keywords: NOx; Low temperature NOx storage; Passive NOx Adsorbers; PNA; DRIFTS; Ce-Pr; and doped ceria.; Chemistry; Inorganic Chemistry
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APA ·
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Manager
APA (6th Edition):
Jones, S. (2016). Ceria Based Catalysts for Low Temperature NOx Storage and Release. (Doctoral Dissertation). University of Kentucky. Retrieved from https://uknowledge.uky.edu/chemistry_etds/67
Chicago Manual of Style (16th Edition):
Jones, Samantha. “Ceria Based Catalysts for Low Temperature NOx Storage and Release.” 2016. Doctoral Dissertation, University of Kentucky. Accessed March 01, 2021.
https://uknowledge.uky.edu/chemistry_etds/67.
MLA Handbook (7th Edition):
Jones, Samantha. “Ceria Based Catalysts for Low Temperature NOx Storage and Release.” 2016. Web. 01 Mar 2021.
Vancouver:
Jones S. Ceria Based Catalysts for Low Temperature NOx Storage and Release. [Internet] [Doctoral dissertation]. University of Kentucky; 2016. [cited 2021 Mar 01].
Available from: https://uknowledge.uky.edu/chemistry_etds/67.
Council of Science Editors:
Jones S. Ceria Based Catalysts for Low Temperature NOx Storage and Release. [Doctoral Dissertation]. University of Kentucky; 2016. Available from: https://uknowledge.uky.edu/chemistry_etds/67
University of Louisville
16.
Hachenberg, Niko, 1981-.
Predictions of NOx emissions in pulverized coal combustion.
Degree: PhD, 2014, University of Louisville
URL: 10.18297/etd/557
;
https://ir.library.louisville.edu/etd/557
► The purpose of this research work was to develop a transferable mathematically simple model which gives the possibility to make fast and easy predictions…
(more)
▼ The purpose of this research work was to develop a transferable mathematically simple model which gives the possibility to make fast and easy predictions regarding the
NOx emission behavior of a broad–spectrum of coals within a certain combustion environment. In this context, this thesis is a further step of a common ongoing investigation focused on predicting
NOx emissions from self–sustaining, pulverized coal combustion in dry bottom firing systems. A comprehensive literature research focused on already published
NOx prediction approaches from scientific publications based on fundamental quantitative relationships or empirical algorithms and statistical relationships was also carried out in this context. This research concentrated on three specific areas which were found to constitute a major gap in the knowledge of
NOx formation in industrial full–scale applications: the fuel properties; the dependence of furnace geometry factors; and the specific operating conditions. The developed model shows a strong statistical significance with a coefficient of determination of 0.9876 and a standard error of 28 mg / m³ STPdry at 6 % O2 based on 142 observations coming from 28 utility boilers. Direct comparisons between model history and observations reported by other researchers have also shown very good conformities. For that background, this thesis form a good basis for identifying individual factors which contributes to system related
NOx emissions in order to investigate how variations in the process parameters affect the emission level. Perhaps, as contribution to the understanding of
NOx formation during coal combustion what is still an imperfectly understood phenomenon, or as basis for possible process optimization which might find application on pulverized coal–fired boilers to make the world a little bit more green.
Advisors/Committee Members: Biles, William E..
Subjects/Keywords: NOx prediction; Effective volatiles; Low-NOx systems; NOx emissions; Combustion optimization; Pulverized coal combustion; Industrial Engineering
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APA (6th Edition):
Hachenberg, Niko, 1. (2014). Predictions of NOx emissions in pulverized coal combustion. (Doctoral Dissertation). University of Louisville. Retrieved from 10.18297/etd/557 ; https://ir.library.louisville.edu/etd/557
Chicago Manual of Style (16th Edition):
Hachenberg, Niko, 1981-. “Predictions of NOx emissions in pulverized coal combustion.” 2014. Doctoral Dissertation, University of Louisville. Accessed March 01, 2021.
10.18297/etd/557 ; https://ir.library.louisville.edu/etd/557.
MLA Handbook (7th Edition):
Hachenberg, Niko, 1981-. “Predictions of NOx emissions in pulverized coal combustion.” 2014. Web. 01 Mar 2021.
Vancouver:
Hachenberg, Niko 1. Predictions of NOx emissions in pulverized coal combustion. [Internet] [Doctoral dissertation]. University of Louisville; 2014. [cited 2021 Mar 01].
Available from: 10.18297/etd/557 ; https://ir.library.louisville.edu/etd/557.
Council of Science Editors:
Hachenberg, Niko 1. Predictions of NOx emissions in pulverized coal combustion. [Doctoral Dissertation]. University of Louisville; 2014. Available from: 10.18297/etd/557 ; https://ir.library.louisville.edu/etd/557
NSYSU
17.
Pan, Chung-po.
Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer.
Degree: Master, Environmental Engineering, 2005, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720105-161929
► In this study, a regenerative thermal oxidizer (RTO) was used to test the relationship between VOC concentration and nitrogen oxides(NOx) formed, and to estimate its…
(more)
▼ In this study, a regenerative thermal oxidizer (RTO) was used to test the relationship between VOC concentration and nitrogen oxides(
NOx) formed, and to estimate its performance. The RTO is electrically heated and contains two 0.152 m à 0.14 m à 1.0 m (L à W à H) beds both packed with gravel particles of around 1.11 cm in average diameter to a height of 1.0 m. The bed has a void fraction of 0.416.
Experiments include two phases: (1) tests to find the VOC destruction and
NOx formed with DMF only in the influent air stream in the following condition: setting temperature Tset=700-900 °C, flowrate Q=0.5-1.0 Am3/min, influent concentration Co=0-500ppm, shift time ts=1.5 min. and before that, to test the effect to thermal recovery efficiency and pressure drop. (2) tests to find the VOC destruction and
NOx formed for the air stream with MEK/DMF mixed in the influent air stream in the following condition: setting temperature Tset=600-900 °C ,flowrate Q=0.5 Am3/min, influent MEK/DMF ratio =100/100,200/100,500/100(ppm/ppm), shift time ts=1.5 min. and before that, to test the effect to thermal recovery efficiency and pressure drop.
Result show : (1)there have no
NOx formed in cool-bed with DMF only in the influent air stream. DMF destruction is proportional to influent concentration(low Co > high Co ) and setting temperature(900 > 800 > 700 °C).
NOx formed is inversely proportional to Co.(2)in the phase two Experiment, DMF destruction is proportional to add MEK in.
NOx formed is inversely proportional to Co. MEK/DMF ratio is proportional to (
NOx formed/DMF removed) at Tset=600 °C,but not closely related during Tset=700-800 °C.NO2 formation is significant at Tset=800 °C. (3)Ergun equation is suitable to estimate pressure drop of RTO.
Advisors/Committee Members: Qi-can Lin (chair), Kang-xing Chen (chair), Ming-xian Chou (committee member).
Subjects/Keywords: NOx; RTO; VOCs
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APA (6th Edition):
Pan, C. (2005). Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720105-161929
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):
Pan, Chung-po. “Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer.” 2005. Thesis, NSYSU. Accessed March 01, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720105-161929.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pan, Chung-po. “Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer.” 2005. Web. 01 Mar 2021.
Vancouver:
Pan C. Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer. [Internet] [Thesis]. NSYSU; 2005. [cited 2021 Mar 01].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720105-161929.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pan C. Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer. [Thesis]. NSYSU; 2005. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720105-161929
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Universidade do Porto
18.
Ferreira, Teresa Sofia Cunha.
Identificação e análise dos parâmetros de operação de um forno de fusão de vidro e a sua influência nas emissões de NOx para a atmosfera.
Degree: 2010, Universidade do Porto
URL: http://www.rcaap.pt/detail.jsp?id=oai:repositorio-aberto.up.pt:10216/71312
► Estágio realizado na empresa BA Vidro, S.A. - Unidade de Avintes e orientado por Sérgio Sousa
Documento confidencial. Não pode ser disponibilizado para consulta
Tese…
(more)
Subjects/Keywords: Emissões de NOx; Indústria do vidro
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APA (6th Edition):
Ferreira, T. S. C. (2010). Identificação e análise dos parâmetros de operação de um forno de fusão de vidro e a sua influência nas emissões de NOx para a atmosfera. (Thesis). Universidade do Porto. Retrieved from http://www.rcaap.pt/detail.jsp?id=oai:repositorio-aberto.up.pt:10216/71312
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):
Ferreira, Teresa Sofia Cunha. “Identificação e análise dos parâmetros de operação de um forno de fusão de vidro e a sua influência nas emissões de NOx para a atmosfera.” 2010. Thesis, Universidade do Porto. Accessed March 01, 2021.
http://www.rcaap.pt/detail.jsp?id=oai:repositorio-aberto.up.pt:10216/71312.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ferreira, Teresa Sofia Cunha. “Identificação e análise dos parâmetros de operação de um forno de fusão de vidro e a sua influência nas emissões de NOx para a atmosfera.” 2010. Web. 01 Mar 2021.
Vancouver:
Ferreira TSC. Identificação e análise dos parâmetros de operação de um forno de fusão de vidro e a sua influência nas emissões de NOx para a atmosfera. [Internet] [Thesis]. Universidade do Porto; 2010. [cited 2021 Mar 01].
Available from: http://www.rcaap.pt/detail.jsp?id=oai:repositorio-aberto.up.pt:10216/71312.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ferreira TSC. Identificação e análise dos parâmetros de operação de um forno de fusão de vidro e a sua influência nas emissões de NOx para a atmosfera. [Thesis]. Universidade do Porto; 2010. Available from: http://www.rcaap.pt/detail.jsp?id=oai:repositorio-aberto.up.pt:10216/71312
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
19.
Reddy, M Srinivasa.
Investigations on reduction of NOx emission in DI diesel
engines through CFD simulation.
Degree: Mechanical Engineering, 2013, Jawaharlal Nehru Technological University, Anantapuram
URL: http://shodhganga.inflibnet.ac.in/handle/10603/13001
► Direct Injection (DI) diesel engines have taken a prominent place in public and private transport. Emissions of the diesel engine emissions Carbon monoxide (CO), Hydro…
(more)
▼ Direct Injection (DI) diesel engines have taken a
prominent place in public and private transport. Emissions of the
diesel engine emissions Carbon monoxide (CO), Hydro Carbon (HC)
have been effectively controlled with improvement in engine deign.
However Nitrogen Oxides (NOx) and soot are still a matter of
concern for the engineers. The main objective of the present work
is to study the ways and means to reduce NOx emission in DI diesel
engines. A significant portion of the combustion process in DI
diesel engines takes place in diffusion flames. Under these
conditions, rates of chemical reaction and heat release are
therefore controlled by rates of fuel-air mixing. The physical
effects, which drive the fuel-air mixing in these engines, appear
to be related to the air motion effects, combustion chamber
geometry and fuel injection process. An understanding of relative
influences of these individual effects is necessary. With the
experimental techniques available today, it is possible to make
reasonably accurate measurements to study the in-cylinder fluid
characteristics. But they are very expensive and time consuming.
Over the past two decades, simulation of fluid dynamic based
multi-dimensional models for studying in-cylinder fluid dynamics
has become popular in the Internal Combustion (IC) engines field.
The main advantages of such models are that they reduce the cost
and time consuming experimental research. ii In this work, an
attempt is made to study the influence of engine operating
parameters on Nitric Oxide (NO) emissions using a Computational
Fluid Dynamic (CFD) code. STAR-CD a 3-dimensional (3-D) CFD code
based on finite volume method has been used for this purpose, which
is capable of solving 3-D unsteady turbulent flows, sprays and
combustion of IC engines. As a first step, a four-stroke single
cylinder Compression Ignition (CI) engine fitted with
hemi-spherical bowl-in-piston for which experimental results are
available is considered to carryout the CFD
analysis.
Conclusion p. 210-213, References p.
214-227
Advisors/Committee Members: Reddy, K Hemachandra.
Subjects/Keywords: CFD simulation; NOx emission; DI diesel engines
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APA (6th Edition):
Reddy, M. S. (2013). Investigations on reduction of NOx emission in DI diesel
engines through CFD simulation. (Thesis). Jawaharlal Nehru Technological University, Anantapuram. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/13001
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):
Reddy, M Srinivasa. “Investigations on reduction of NOx emission in DI diesel
engines through CFD simulation.” 2013. Thesis, Jawaharlal Nehru Technological University, Anantapuram. Accessed March 01, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/13001.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Reddy, M Srinivasa. “Investigations on reduction of NOx emission in DI diesel
engines through CFD simulation.” 2013. Web. 01 Mar 2021.
Vancouver:
Reddy MS. Investigations on reduction of NOx emission in DI diesel
engines through CFD simulation. [Internet] [Thesis]. Jawaharlal Nehru Technological University, Anantapuram; 2013. [cited 2021 Mar 01].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/13001.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Reddy MS. Investigations on reduction of NOx emission in DI diesel
engines through CFD simulation. [Thesis]. Jawaharlal Nehru Technological University, Anantapuram; 2013. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/13001
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
20.
Naser, Mona Ahmad Hussein.
Utility System Optimization Under Air Quality Considerations.
Degree: MS, Chemical Engineering, 2018, Texas A&M University
URL: http://hdl.handle.net/1969.1/173540
► Air pollution is a primary concern, and one of its major contributors is industry. Optimization of emissions from industrial facilities is well established in publications…
(more)
▼ Air pollution is a primary concern, and one of its major contributors is industry. Optimization of emissions from industrial facilities is well established in publications and reports. However, it does not extend beyond the stack or exhaust level i.e., emissions released to the atmosphere.
This work aspires to develop and test a methodology to optimize the operational scheme of a utility system considering air quality in the area around the facility by combining Process Design with Air Dispersion Modelling. The concept of this work is to investigate if atmospheric dispersion modeling can be used to improve pollution prevention/control by observing ground level concentration in the surrounding area of the unit at various operating scenarios and in different weather conditions. The methodology has been implemented in MATLAB following the coupling of a simple Gaussian dispersion model with a process model, both supplied with real meteorological and process data.
The case study used to test the methodology is a High Pressure Steam (HPS) generation unit. It consists of three identical boilers where the operational strategy is to operate two boilers, and the third is stand-by. The boilers accept two types of fuels: gas and liquid. Two separate optimization goals were studied. The first is to improve air quality in the surrounding area, i.e., minimize the ground level concentration, by changing the operating scheme of the three boilers. The second optimization goal is to reduce the operating costs by optimizing the ratio of the two fuels while keeping the resulting ground level concentration just below the regulations limit.
Finally, the methodology allowed to derive and assess the different operational strategies. The first goal improved the overall air quality and reached up to 46% reduction of the maximum concentration exceedances. The second goal proved that facilities can reduce operational costs and still be in compliance with environmental regulations. On the other hand, this cost reduction does lead to a decrease of overall air quality, since the average ground level concentration is increased. In the future, this methodology could be applied to more case studies and at the industrial city level to improve air quality and to assist on more appropriate environmental policies.
Advisors/Committee Members: Kakosimos , Konstantinos (advisor), Linke, Patrick (advisor), El-Halwagi, Mahmoud (committee member), Parsaei, Hamid (committee member).
Subjects/Keywords: Optimization; Air Dispersion Modeling; Operational Strategy; NOx
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APA (6th Edition):
Naser, M. A. H. (2018). Utility System Optimization Under Air Quality Considerations. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173540
Chicago Manual of Style (16th Edition):
Naser, Mona Ahmad Hussein. “Utility System Optimization Under Air Quality Considerations.” 2018. Masters Thesis, Texas A&M University. Accessed March 01, 2021.
http://hdl.handle.net/1969.1/173540.
MLA Handbook (7th Edition):
Naser, Mona Ahmad Hussein. “Utility System Optimization Under Air Quality Considerations.” 2018. Web. 01 Mar 2021.
Vancouver:
Naser MAH. Utility System Optimization Under Air Quality Considerations. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1969.1/173540.
Council of Science Editors:
Naser MAH. Utility System Optimization Under Air Quality Considerations. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173540
Texas A&M University
21.
Pemelton, John.
Shock-Tube Study of Methane Ignition with NO2 and N2O.
Degree: MS, Mechanical Engineering, 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188
► NOx produced during combustion can persist in the exhaust gases of a gas turbine engine in quantities significant to induce regulatory concerns. There has been…
(more)
▼ NOx produced during combustion can persist in the exhaust gases of a gas turbine engine in quantities significant to induce regulatory concerns. There has been much research which has led to important insights into
NOx chemistry. One method of
NOx reduction is exhaust gas recirculation. In exhaust gas recirculation, a portion of the exhaust gases that exit are redirected to the inlet air stream that enters the combustion chamber, along with fuel. Due to the presence of
NOx in the exhaust gases which are subsequently introduced into the burner, knowledge of the effects of
NOx on combustion is advantageous. Contrary to general
NOx research, little has been conducted to investigate the sensitizing effects of NO2 and N2O addition to methane/oxygen combustion.
Experiments were made with dilute and real fuel air mixtures of CH4/O2/Ar with the addition of NO2 and N2O. The real fuel air concentrations were made with the addition of NO2 only. The equivalence ratios of mixtures made were 0.5, 1 and 2. The experimental pressure range was 1 - 44 atm and the temperature range tested was 1177 – 2095 K. The additives NO2 and N2O were added in concentrations from 831 ppm to 3539 ppm. The results of the mixtures with NO2 have a reduction in ignition delay time across the pressure ranges tested, and the mixtures with N2O show a similar trend. At 1.3 atm, the NO2 831 ppm mixture shows a 65% reduction and shows a 75% reduction at 30 atm. The NO2 mixtures showed a higher decrease in ignition time than the N2O mixtures. The real fuel air mixture also showed a reduction.
Sensitivity Analyses were performed. The two most dominant reactions in the NO2 mixtures are the reaction O+H2 = O+OH and the reaction CH3+NO2 = CH3O+NO. The presence of this second reaction is the means by which NO2 decreases ignition delay time, which is indicated in the experimental results. The reaction produces CH3O which is reactive and can participate in chain propagating reactions, speeding up ignition.
The two dominant reactions for the N2O mixture are the reaction O+H2 = O+OH and, interestingly, the other dominant reaction is the reverse of the initiation reaction in the N2O-mechanism: O+N2+M = N2O+M. The reverse of this reaction is the direct oxidation of nitrous oxide. The O produced in this reaction can then speed up ignition by partaking in propagation reactions, which was experimentally observed.
Advisors/Committee Members: Petersen, Eric L. (advisor), Annamalai, Kalyan (committee member), Bowersox, Rodney (committee member).
Subjects/Keywords: Ignition Delay; NOx chemistry; Shock Tube
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APA (6th Edition):
Pemelton, J. (2012). Shock-Tube Study of Methane Ignition with NO2 and N2O. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188
Chicago Manual of Style (16th Edition):
Pemelton, John. “Shock-Tube Study of Methane Ignition with NO2 and N2O.” 2012. Masters Thesis, Texas A&M University. Accessed March 01, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188.
MLA Handbook (7th Edition):
Pemelton, John. “Shock-Tube Study of Methane Ignition with NO2 and N2O.” 2012. Web. 01 Mar 2021.
Vancouver:
Pemelton J. Shock-Tube Study of Methane Ignition with NO2 and N2O. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188.
Council of Science Editors:
Pemelton J. Shock-Tube Study of Methane Ignition with NO2 and N2O. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188
Penn State University
22.
Stines, Zachary O'cain.
Reducing the Impact of the Power Sector on Ozone Pollution: An Evaluation of Spatial and Temporal Differentiated Prices for Nitrogen Oxide Emissions.
Degree: 2016, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/28885
► Nitrogen oxide (NOx) is a common air pollutant that has impacts on human health and is a precursor to the formation of tropospheric (ground-level) ozone.…
(more)
▼ Nitrogen oxide (
NOx) is a common air pollutant that has impacts on human health and is a precursor to the formation of tropospheric (ground-level) ozone. The U.S. Environmental Protection Agency therefore regulates the emissions of nitrogen oxides through the Clean Air Act and the National Ambient Air Quality Standards (NAAQS). Approximately 14% of all
NOx emissions are produced by the electric power sector and as a result, regulations are often applied directly to the sector. However despite the success of regulations at reducing the amount of
NOx emissions over the last several decades, areas not meeting the ozone NAAQS still persist. Further reductions of emissions using current approaches result in rapidly increasing marginal costs. As a product, new research is needed to design and evaluate the effectiveness of alternative regulatory designs in reducing ground-level ozone.
This thesis seeks to evaluate and compare three regulatory designs: undifferentiated pricing, time differentiated pricing, and time and space differentiated pricing. Undifferentiated pricing is used to represent the current Cross-state Air Pollution Rule with constant emissions prices. Time differentiated pricing sets a higher emission price on days designated as having increased ozone formation. Time and space differentiated pricing would operate similarly to time differentiated pricing, except that different emission prices are applied to different regions. A unit commitment model is used to simulate the different regulatory designs for a study region based on the Electric Reliability Council of Texas (ERCOT) and to evaluate the cost and emissions impacts on the system. The short-term impacts result from the redispatching of resources to lower emitting generators and to generators not located within a region marked by higher permit prices.
The results show that of the scenarios analyzed, time and space differentiated pricing is cost effective at reducing
NOx emission prices in the nonattainment region on high ozone days, while time differentiation was the most cost-effective method at reducing system-wide emissions on high ozone days. The study also demonstrates the importance of the relative price differential between the emission prices of regions when utilizing time and space differentiated pricing. In particular, smaller differentials result in the greatest reduction in both the nonattainment and system-wide emissions. Very large differentials induce a shift of lower emitting gas generation in nonattainment regions to higher emitting coal generation in attainment regions, which increases the net
NOx emissions for the system as a whole.
Advisors/Committee Members: Mort D Webster, Thesis Advisor/Co-Advisor.
Subjects/Keywords: Ozone; NOx; Electricity; Differentiated; Emissions; Spatial
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APA ·
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MLA ·
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Manager
APA (6th Edition):
Stines, Z. O. (2016). Reducing the Impact of the Power Sector on Ozone Pollution: An Evaluation of Spatial and Temporal Differentiated Prices for Nitrogen Oxide Emissions. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/28885
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):
Stines, Zachary O'cain. “Reducing the Impact of the Power Sector on Ozone Pollution: An Evaluation of Spatial and Temporal Differentiated Prices for Nitrogen Oxide Emissions.” 2016. Thesis, Penn State University. Accessed March 01, 2021.
https://submit-etda.libraries.psu.edu/catalog/28885.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Stines, Zachary O'cain. “Reducing the Impact of the Power Sector on Ozone Pollution: An Evaluation of Spatial and Temporal Differentiated Prices for Nitrogen Oxide Emissions.” 2016. Web. 01 Mar 2021.
Vancouver:
Stines ZO. Reducing the Impact of the Power Sector on Ozone Pollution: An Evaluation of Spatial and Temporal Differentiated Prices for Nitrogen Oxide Emissions. [Internet] [Thesis]. Penn State University; 2016. [cited 2021 Mar 01].
Available from: https://submit-etda.libraries.psu.edu/catalog/28885.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Stines ZO. Reducing the Impact of the Power Sector on Ozone Pollution: An Evaluation of Spatial and Temporal Differentiated Prices for Nitrogen Oxide Emissions. [Thesis]. Penn State University; 2016. Available from: https://submit-etda.libraries.psu.edu/catalog/28885
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Newcastle
23.
Venpin, Wendy Koo Pao Foon.
Chemical trapping of nitric oxide by aromatic nitroso sulfonates.
Degree: PhD, 2013, University of Newcastle
URL: http://hdl.handle.net/1959.13/1038349
► Research Doctorate - Doctor of Philosophy (PhD)
This thesis investigates the employment of spin traps as NOx scavengers to control noxious NOx formation during nitrosation…
(more)
▼ Research Doctorate - Doctor of Philosophy (PhD)
This thesis investigates the employment of spin traps as NOx scavengers to control noxious NOx formation during nitrosation reactions. Most notably, the reaction conditions studied are relevant to the sensitisation of emulsion explosives activated by the chemical gassing, where the formation of these gases can trigger serious respiratory problems to explosives users. Spin traps are widely used by biochemists to detect and measure free radicals such as nitric oxide (NO) in biological systems. The spin trapping reaction involves the addition of a radical to the spin trap, which results in the formation of a complex adduct, detectable by electron paramagnetic resonance (EPR). Intuitively, as a result of the effect of the spin trapping reaction on free radical, these spin traps can potentially play an important role in the development of a new technology to reduce NOx emission. Four aromatic ortho substituted nitroso compounds, 3,5-dibromo-4-nitrosobenzene sulfonate (DBNBS), nitrosobenzene sulfonate (NBS), 3,5-dimethyl-4-nitrosobenzene sulfonate (DMNBS) and 3,5-dichloro-4-nitrosobenzene sulfonate (DCNBS) were subjected to detailed experimental and theoretical investigation in this thesis. These compounds were synthesised by the oxidation of their corresponding amine compounds and characterised by infrared (IR), ultraviolet visible (UV-Vis), nuclear magnetic resonance (NMR) spectroscopy and nanostructured assisted laser desorption ionisation mass spectrometric (NALDI-MS). The thesis initially studied the reaction of DBNBS with NO, where NO was generated in an acidic nitrite solution, conditions which are similar to the chemical gassing process of emulsion explosives, by examining gaseous and liquid products from the reaction. Membrane inlet mass spectrometer (MIMS) analysis disclosed the presence of significant amount of nitrogen gas (N₂) in the gas phase, whereas ion chromatographic analysis of the reaction mixture disclosed elevated amounts of nitrate were formed during the gassing reaction. During the reaction, DBNBS initially reacts with NO to form a short live DBNBS-NO adduct. The release of N₂ is a consequence of the homolytic cleavage of the C-N bond of a diazenyl radical. This assertion is based on quantum chemical calculations (Density Functional Theory) which validates the favourable formation of a diazenyl radical as well as oxygen. The elevated concentration of nitrate in solution provides additional evidence of the presence of oxygen released as a result of the decomposition of the radical intermediate (DBNBS-NO adduct). NALDI-MS analysis of liquid products in the study enabled the identification of 3,4,5-trinitrobenzene sulfonate (MW of 291.888 a.m.u) as the primary product from the reaction, and a number of other nitro compounds were also identified. Analysis of the gaseous and liquid products, in particular the NALDI-MS technique, demonstrates that the presence of nitrite leads to the formation of a competing reaction pathway whereby nitro group is…
Advisors/Committee Members: University of Newcastle. Faculty of Engineering & Built Environment, School of Engineering.
Subjects/Keywords: nitric oxide; scavenger; NOx control; emulsion explosives
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APA (6th Edition):
Venpin, W. K. P. F. (2013). Chemical trapping of nitric oxide by aromatic nitroso sulfonates. (Doctoral Dissertation). University of Newcastle. Retrieved from http://hdl.handle.net/1959.13/1038349
Chicago Manual of Style (16th Edition):
Venpin, Wendy Koo Pao Foon. “Chemical trapping of nitric oxide by aromatic nitroso sulfonates.” 2013. Doctoral Dissertation, University of Newcastle. Accessed March 01, 2021.
http://hdl.handle.net/1959.13/1038349.
MLA Handbook (7th Edition):
Venpin, Wendy Koo Pao Foon. “Chemical trapping of nitric oxide by aromatic nitroso sulfonates.” 2013. Web. 01 Mar 2021.
Vancouver:
Venpin WKPF. Chemical trapping of nitric oxide by aromatic nitroso sulfonates. [Internet] [Doctoral dissertation]. University of Newcastle; 2013. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1959.13/1038349.
Council of Science Editors:
Venpin WKPF. Chemical trapping of nitric oxide by aromatic nitroso sulfonates. [Doctoral Dissertation]. University of Newcastle; 2013. Available from: http://hdl.handle.net/1959.13/1038349
University of Connecticut
24.
Yang, Hongtao.
Emission Modeling in Turbulent Premixed Flames.
Degree: MS, Mechanical Engineering, 2013, University of Connecticut
URL: https://opencommons.uconn.edu/gs_theses/479
► Turbulent lean premixed combustion now plays a predominant role in reducing emission of pollutants such as NOx. For turbulent premixed flames located in the…
(more)
▼ Turbulent lean premixed combustion now plays a predominant role in reducing emission of pollutants such as
NOx. For turbulent premixed flames located in the thin-reaction-zones regime, small-scale eddies could penetrate into the preheat zone of the flames and enhance the mixing process. In this study, the effects of small-scale turbulence on emission (
NOx and CO) formation in premixed flame fronts are investigated through the incorporation of turbulence induced diffusion in the preheat zone of one-dimensional premixed flames. One-dimensional methane/air premixed flames are simulated with the 53-species GRI-Mech 3.0 mechanism at both atmospheric and engine conditions with different turbulence intensities. It is found that the NO generated in flame fronts deceases with increasing intensity of small-scale turbulence and the effect is more profound at high pressures. At high pressures, the turbulence induced diffusion in the preheat zone can reduce the
NOx formation in flame fronts by more than 40%. On the other hand, the CO mass fraction in flame fronts increases with increasing intensity of small-scale turbulence. In the cases considered, the CO mass fraction in the flame fronts can increase by more than 55%. In addition, a flamelet-based approach that accounts for the flame thickening effects has been formulated to simulate
NOx and CO formation in turbulent lean premixed combustion. In this approach, the species NO and CO are transported and solved in a simulation with chemical source terms being pre-calculated from 1-D premixed flames with detailed chemical kinetics and turbulence induced diffusion. The NO source term can be quantified by its formation in flame fronts and its formation rate in post-flame region. The CO source term can be calculated through its mass fraction at flame fronts, its mass fraction in the post-flame region and an oxidation time scale. The effect of heat loss on NO formation has been studied by investigate the relation between post-flame NO formation rate and flame temperature. Meanwhile, the effect of turbulent-chemistry interaction on NO were studied. The flamelet-based emission model has been implemented into Fluent and 3-Dimensional simulations were conducted in a combustion rig.
Advisors/Committee Members: Tianfeng Lu, Tai-Hsi Fan, Zhuyin Ren.
Subjects/Keywords: combustion; emission modeling; NOx; flamelet; premixed flame
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APA (6th Edition):
Yang, H. (2013). Emission Modeling in Turbulent Premixed Flames. (Masters Thesis). University of Connecticut. Retrieved from https://opencommons.uconn.edu/gs_theses/479
Chicago Manual of Style (16th Edition):
Yang, Hongtao. “Emission Modeling in Turbulent Premixed Flames.” 2013. Masters Thesis, University of Connecticut. Accessed March 01, 2021.
https://opencommons.uconn.edu/gs_theses/479.
MLA Handbook (7th Edition):
Yang, Hongtao. “Emission Modeling in Turbulent Premixed Flames.” 2013. Web. 01 Mar 2021.
Vancouver:
Yang H. Emission Modeling in Turbulent Premixed Flames. [Internet] [Masters thesis]. University of Connecticut; 2013. [cited 2021 Mar 01].
Available from: https://opencommons.uconn.edu/gs_theses/479.
Council of Science Editors:
Yang H. Emission Modeling in Turbulent Premixed Flames. [Masters Thesis]. University of Connecticut; 2013. Available from: https://opencommons.uconn.edu/gs_theses/479
Harvard University
25.
Silvern, Rachel Faye.
Using Orbital and Suborbital Observations to Constrain US Air Quality Trends.
Degree: PhD, 2019, Harvard University
URL: http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029828
► Ozone (O3) and particulate matter (PM) pollution in surface air are harmful to human health and the environment. Tropospheric ozone is produced by photochemical oxidation…
(more)
▼ Ozone (O3) and particulate matter (PM) pollution in surface air are harmful to human health and the environment. Tropospheric ozone is produced by photochemical oxidation of volatile organic compounds (VOCs) in the presence of nitrogen oxide radicals (
NOx = NO + NO2) and PM is directly emitted or formed in the atmosphere from oxidation and subsequent condensation of precursor gases (SO2, NH3,
NOx, VOCs) into the aqueous aerosol phase. In effort to improve US air quality, the Environmental Protection Agency (EPA) has been regulating these precursor emissions since the 1970s under the Clean Air Act. As emissions have drastically decreased and the dominant pollution sources have changed, regulatory control strategies must adapt in order to continue to limit human and environmental exposure to ozone and PM.
This thesis aims to address the emissions and formation processes that control ambient ozone and aerosol concentrations in surface air and the troposphere in the US over the past decade. The objectives of this work are to investigate the (1) processes controlling aerosol formation and composition in response to changes in emissions, (2) gas phase chemical cycling in the upper troposphere, and (3) consistency between long-term trends in US
NOx emissions and satellite observations. In order to address these questions, we rely on a wide range of atmospheric observations from surface networks, aircraft campaigns, and satellite observations, with a specific focus on the Southeast US in summer where observations are particularly comprehensive. Additionally, we use the 3D chemical transport model, GEOS-Chem, as a tool to interpret these atmospheric observations and identify gaps in our understanding of the chemical and physical processes controlling atmospheric pollutants.
In this thesis, we identify a fundamental discrepancy between thermodynamic equilibrium theory and observations of inorganic aerosol composition in the eastern US in summer that show low ammonium-sulfate aerosol ratios. In addition, we show that from 2003 to 2013, while SO2 emissions have declined due to US emission controls, aerosols have become more acidic in the Southeastern US. To explain these observations, we suggest that the large and increasing source of organic aerosol may be affecting thermodynamic equilibrium.
Next, we investigate the chemistry controlling NO and NO2 in the upper troposphere by identifying large inconsistencies between observed and modeled NO/NO2 ratios over the Southeast US during August–September 2013. We suggest that either unrecognized chemistry or errors in modeled cycling between NO, NO2, and O3 could explain this discrepancy. We discuss how either explanation will have important implications for global tropospheric chemistry and for the interpretation of satellite observations of NO2.
The EPA reports a steady decrease in
NOx emissions from fuel combustion over the 2005–2017 period, while satellite observations show a leveling off after 2009 suggesting emission reductions and related air quality gains have halted. In…
Advisors/Committee Members: Tziperman, Eli (advisor).
Subjects/Keywords: air quality; ozone; NOx; PM2.5; GEOS-Chem
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APA (6th Edition):
Silvern, R. F. (2019). Using Orbital and Suborbital Observations to Constrain US Air Quality Trends. (Doctoral Dissertation). Harvard University. Retrieved from http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029828
Chicago Manual of Style (16th Edition):
Silvern, Rachel Faye. “Using Orbital and Suborbital Observations to Constrain US Air Quality Trends.” 2019. Doctoral Dissertation, Harvard University. Accessed March 01, 2021.
http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029828.
MLA Handbook (7th Edition):
Silvern, Rachel Faye. “Using Orbital and Suborbital Observations to Constrain US Air Quality Trends.” 2019. Web. 01 Mar 2021.
Vancouver:
Silvern RF. Using Orbital and Suborbital Observations to Constrain US Air Quality Trends. [Internet] [Doctoral dissertation]. Harvard University; 2019. [cited 2021 Mar 01].
Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029828.
Council of Science Editors:
Silvern RF. Using Orbital and Suborbital Observations to Constrain US Air Quality Trends. [Doctoral Dissertation]. Harvard University; 2019. Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029828
Delft University of Technology
26.
Leune, Benjamin (author).
Detailed mapping of NO₂ pollution sources with the TROPOMI instrument operated in zoom-mode.
Degree: 2019, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:528cb172-3bee-4274-bb6f-25add2f17865
► Anthropogenic nitrogen dioxide (NO₂) in the troposphere is mainly produced by combustion engines in traffic, industry and energy production, and continues to affect air quality,…
(more)
▼ Anthropogenic nitrogen dioxide (NO₂) in the troposphere is mainly produced by combustion engines in traffic, industry and energy production, and continues to affect air quality, human health and environment. Daily global measurements of tropospheric NO₂ columns are obtained by satellites with increasing spatial resolution and signal-to-noise levels, to improve monitoring of emission sources and air quality forecasting. The recently launched TROPOMI instrument on-board ESA’s Sentinel-5 Precursor satellite measures tropospheric NO₂ with a spatial resolution of 7.1 km by 3.6 km. During its commissioning phase, the instrument was temporarily operated in ’zoom-mode’ to measure at a resolution of 2.4 km by 1.8 km. This research presents the processed results from this unique data-set, which allows mapping NO₂ pollution sources from space with unprecedented detail. Comparison to measurements at operational resolution shows the improvement in spatial information content, at the cost of increased noise and uncertainty. The benefits and possibilities of measuring tropospheric NO₂ at high resolution are explored with several case studies. Comparisons with chemical transfer model forecasts show the improved ability of these measurements to capture local NO₂ enhancements and possibly improve emission inventories. The found correlations with co-located space-borne CO₂ column observations and the performance of a plume detection algorithm applied to the data-set provide additional support for simultaneous high resolution measurements of co-emitted CO₂ and NO₂, planned for future satellites to improve CO₂ emission monitoring. Finally, test retrievals with the zoom-mode data, using experimental high resolution surface reflectivity and NO₂ profile shape input, demonstrate the potential impact of high resolution a priori databases on the retrieval performance.
Double Master’s Degree programme, combining the Space Flight track from the Aerospace Engineering MSc programme at the Faculty of Aerospace Engineering with the Geoscience and Remote Sensing track from the Applied Earth Sciences MSc programme at the Faculty of Civil Engineering and Geosciences
Advisors/Committee Members: Vlemmix, Tim (mentor), Veefkind, j. Pepijn (mentor), Stam, Daphne (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: TROPOMI; NOx; air quality; remote sensing
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APA (6th Edition):
Leune, B. (. (2019). Detailed mapping of NO₂ pollution sources with the TROPOMI instrument operated in zoom-mode. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:528cb172-3bee-4274-bb6f-25add2f17865
Chicago Manual of Style (16th Edition):
Leune, Benjamin (author). “Detailed mapping of NO₂ pollution sources with the TROPOMI instrument operated in zoom-mode.” 2019. Masters Thesis, Delft University of Technology. Accessed March 01, 2021.
http://resolver.tudelft.nl/uuid:528cb172-3bee-4274-bb6f-25add2f17865.
MLA Handbook (7th Edition):
Leune, Benjamin (author). “Detailed mapping of NO₂ pollution sources with the TROPOMI instrument operated in zoom-mode.” 2019. Web. 01 Mar 2021.
Vancouver:
Leune B(. Detailed mapping of NO₂ pollution sources with the TROPOMI instrument operated in zoom-mode. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 01].
Available from: http://resolver.tudelft.nl/uuid:528cb172-3bee-4274-bb6f-25add2f17865.
Council of Science Editors:
Leune B(. Detailed mapping of NO₂ pollution sources with the TROPOMI instrument operated in zoom-mode. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:528cb172-3bee-4274-bb6f-25add2f17865
Tampere University
27.
Senttula, Tuukka.
Data driven soft sensor for diesel engine emissions
.
Degree: 2020, Tampere University
URL: https://trepo.tuni.fi/handle/10024/121927
► The objective of this thesis was to compare different machine learning models for predicting raw nitrogen oxides values produced by non-road diesel combustion engine in…
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▼ The objective of this thesis was to compare different machine learning models for predicting raw nitrogen oxides values produced by non-road diesel combustion engine in non-laboratory environment. The models were evaluated by their accuracy and also by their ability to run real time. If the evaluation is enough, the predictor could be used to replace the real sensor.
The available data came from dozens of different engines: different engine types, different power restrictions, different applications such as tractors and harvesters. Some of the engines were in laboratory environment when the rest were in real customer use. In this thesis the training of the models is done with the data of a single customer use engine and the evaluation data is from crossvalidated data from the same engine, a combine harvester, a forwarder and a laboratory engine. The selected evaluation engines meet the stage V emission limits and are all exactly the same engines except their different software, engine aftertreatment system and type of work.
Results show that it is not possible to get similar accuracy as the real sensor with fast models, but it is possible to get close, especially in high engine speeds. Models with high prediction power have better results and it might be possible to exceed the real sensor accuracy, but with the cost of slower prediction. LSTM models perform better than other types of models.
Tämän työn tarkoitus oli vertailla eri koneoppimismalleja typpioksidiarvojen ennustamiseen dieselmoottorin raakapäästöistä kenttäolosuhteissa. Malleja evaluoidaan niiden tarkkuuden sekä kyvyn reaaliaikaisuuden mukaan ja mikäli evaluaatio on hyvä, mallia voidaan käyttää korvaamaan oikea sensori.
Käytetty data tulee monesta erilaisesta moottorista: eri tyyppisistä, eri tehorajoitetuista, eri applikaatioista kuten puimuri tai traktori sekä laboratorio- ja asiakaskäytössä olevista. Tässä työssä oppimisdatana käytetään vain yhtä asiakaskäytössä olevan traktorin dataa ja evaluointidatana käytetään saman moottorin ristiinvalidoitua dataa sekä puimurin, kuormatraktorin ja laboratoriomoottorin dataa. Valitut moottorit noudattavat stage V päästörajoituksia ja ovat täysin sama moottori erotuksena niiden ohjelmisto, jälkikäsittelyjärjestelmä ja työn tyyppi.
Tulokset näyttävät ettei ole mahdollista päästä oikean sensorin tarkkuuteen nopeilla malleilla, mutta lähelle on mahdollista päästä etenkin korkeissa moottorin pyörimisnopeuksissa. Suuremmat mallit saivat parhaita tuloksia ja on mahdollista että ne sivuaisivat oikean sensorin tarkkuutta, mutta mallin nopeus kärsii koon kasvaessa. LSTM mallit toimivat muita malleja paremmin.
Subjects/Keywords: machine learning
;
NOx emissions
;
diesel engine
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APA (6th Edition):
Senttula, T. (2020). Data driven soft sensor for diesel engine emissions
. (Masters Thesis). Tampere University. Retrieved from https://trepo.tuni.fi/handle/10024/121927
Chicago Manual of Style (16th Edition):
Senttula, Tuukka. “Data driven soft sensor for diesel engine emissions
.” 2020. Masters Thesis, Tampere University. Accessed March 01, 2021.
https://trepo.tuni.fi/handle/10024/121927.
MLA Handbook (7th Edition):
Senttula, Tuukka. “Data driven soft sensor for diesel engine emissions
.” 2020. Web. 01 Mar 2021.
Vancouver:
Senttula T. Data driven soft sensor for diesel engine emissions
. [Internet] [Masters thesis]. Tampere University; 2020. [cited 2021 Mar 01].
Available from: https://trepo.tuni.fi/handle/10024/121927.
Council of Science Editors:
Senttula T. Data driven soft sensor for diesel engine emissions
. [Masters Thesis]. Tampere University; 2020. Available from: https://trepo.tuni.fi/handle/10024/121927
28.
Hilton Costa Louzeiro.
Microemulsões combustíveis a partir do óleo de babaçu para substituir o diesel em motores estacionários.
Degree: 2012, Universidade Federal da Paraíba
URL: http://bdtd.biblioteca.ufpb.br/tde_busca/arquivo.php?codArquivo=2513
► Os óleos vegetais constituem uma alternativa renovável para substituir o diesel por causarem um menor impacto ambiental. Entretanto, devido suas propriedades fluidodinâmicas, o seu uso…
(more)
▼ Os óleos vegetais constituem uma alternativa renovável para substituir o diesel por causarem um menor impacto ambiental. Entretanto, devido suas propriedades fluidodinâmicas, o seu uso in natura em motores é limitado. Ainda assim, os mesmos podem ser utilizados como componentes de microemulsões combustíveis. O objetivo deste trabalho é obter três diferentes sistemas microemulsionados de óleo de babaçu e avaliar se os mesmos apresentam características de combustíveis. Inicialmente, foi se construindo um diagrama de fases pseudoternário para cada sistema. Na região homogênea de cada diagrama foram selecionadas proporções, em massa, de cada componente. Os sistemas microemulsionados estudados receberam a seguinte denominação: MAIb,formado por 54:3:43 % (m/m) (óleo de babaçu refinado: aguardente:álcool isobutílico). MAIa, formado por 51:1:48 % (m/m) (óleo de babaçu refinado: aguardente: álcool isoamílico) e MEF, formado por 49:5:46 % (m/m) (óleo de babaçu refinado: etanol hidratado: óleo fúsel). Os três sistemas foram submetidos à análise por espalhamento de luz, onde se observou que os mesmos apresentam tamanho de gotículas, característico de microemulsões, ou seja, 3,80; 1,55 e 26,0 nm para MAIb, MAIa e MEF, respectivamente. Logo após, foram preparadas misturas desses sistemas com o diesel, na proporção de [10, 20 e 30 % (m/m)]. Em seguida, cada microemulsão pura ou misturada ao diesel foi submetida a análises de caracterização (viscosidade cinemática a 40 C, massa específica a 20 C, ponto de fulgor, turbidez e índice de acidez), obtendo-se resultados satisfatórios. Também foram determinados os níveis de emissão e o número de cetano para os combustíveis. Os resultados mostraram uma diminuição das emissões de CO e uma elevação das emissões de NOx para o sistema MEF, para a microemulsão pura do sistema MAIa e para a sua mistura 30 % com o diesel. Os demais combustíveis emitiram menos NOx que o diesel. Quanto ao número de cetano, este foi menor que o determinado para o diesel em todas as misturas combustíveis. Dessa forma, acredita-se que é possível utilizar as microemulsões como combustíveis em substituição parcial ou total ao diesel, podendo utilizar uma ampla variedade de composições, a maioria disponível em localidades remotas.
Vegetable oils can be used as alternative for diesel fuel, due to their combustion characteristics and low environmental impact. However, due to their fluid dynamic properties its usage "in nature" is limited. But they may be used as a component for microemulsion fuels. In such context, the present work aims to obtain, characterize and evaluate the combustion properties of three different babassu microemulsions. Therefore, pseudo-ternary phase diagrams were constructed for each system. According to the phase diagrams, the following homogeneous regions were selected: MAIb consisting of 54:3:43 %(m/m.) (refined babassu oil: distilled alcohol: isobutyl alcohol); MAIa consisting of 51:1:48 %(m/m.) (refined babassu oil: distilled alcohol: isoamyl alcohol); MEF consisting of 49:5:46 %( m/m)…
Advisors/Committee Members: Antonio Gouveia de Souza, Fernando Carvalho Silva.
Subjects/Keywords: Microemulsion; Combustível; Microemulsão; Emissões de CO e NOx; QUIMICA; Fuel; Emissions of CO and NOx
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APA (6th Edition):
Louzeiro, H. C. (2012). Microemulsões combustíveis a partir do óleo de babaçu para substituir o diesel em motores estacionários. (Thesis). Universidade Federal da Paraíba. Retrieved from http://bdtd.biblioteca.ufpb.br/tde_busca/arquivo.php?codArquivo=2513
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):
Louzeiro, Hilton Costa. “Microemulsões combustíveis a partir do óleo de babaçu para substituir o diesel em motores estacionários.” 2012. Thesis, Universidade Federal da Paraíba. Accessed March 01, 2021.
http://bdtd.biblioteca.ufpb.br/tde_busca/arquivo.php?codArquivo=2513.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Louzeiro, Hilton Costa. “Microemulsões combustíveis a partir do óleo de babaçu para substituir o diesel em motores estacionários.” 2012. Web. 01 Mar 2021.
Vancouver:
Louzeiro HC. Microemulsões combustíveis a partir do óleo de babaçu para substituir o diesel em motores estacionários. [Internet] [Thesis]. Universidade Federal da Paraíba; 2012. [cited 2021 Mar 01].
Available from: http://bdtd.biblioteca.ufpb.br/tde_busca/arquivo.php?codArquivo=2513.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Louzeiro HC. Microemulsões combustíveis a partir do óleo de babaçu para substituir o diesel em motores estacionários. [Thesis]. Universidade Federal da Paraíba; 2012. Available from: http://bdtd.biblioteca.ufpb.br/tde_busca/arquivo.php?codArquivo=2513
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Houston
29.
Shakya, Bijesh Man.
Studies of Platinum Dispersion and Catalyst Architecture for Lean NOx Reduction.
Degree: PhD, Chemical Engineering, 2013, University of Houston
URL: http://hdl.handle.net/10657/1194
► The combination of NOx storage and reduction (NSR) and selective catalytic reduction (SCR) catalyst is a promising technology for the reduction of NOx emission from…
(more)
▼ The combination of
NOx storage and reduction (NSR) and selective catalytic reduction (SCR) catalyst is a promising technology for the reduction of
NOx emission from the exhaust of lean-burn or diesel engine vehicles. In the combined NSR/SCR system, NH3 generated in LNT during the rich phase is utilized in the SCR for additional
NOx conversion. Therefore, the performance of the combined NSR/SCR depends strongly on the NH3 generating function of the NSR catalyst. Earlier studies show that lower Pt dispersion NSR catalysts give higher selectivity to NH3 making them ideal candidates for this particular application.
In the first part of the work, we performed experiments on lower Pt dispersion catalysts to gain insights on the mechanistic effects of Pt dispersion on
NOx conversion and selectivity. We also developed an improved crystallite-scale model of NSR that explicitly accounts for the crystallite scale gradients of the stored
NOx. The calibrated model is able to capture the effects of Pt dispersion, rich phase duration and overall cycle time on cycle-averaged conversion and selectivity trends.
In the second part, we carried out a simulation study of dual-layer NSR+SCR monolithic catalyst using (1+1)-D model of catalytic monolith with individually-calibrated global kinetic models. Simulations show that multiple combinations of catalyst loading can attain a given
NOx conversion and N2 selectivity, and that there exists a loading of SCR washcoat for a given NSR catalyst for which the
NOx conversion is maximum. Simulations of the dual-brick monolith are also performed to analyze the effects of catalyst architecture. Under identical conditions, the simulations show that dual-layer catalyst outperforms the dual-brick largely because of the better utilization of generated NH3.
Finally, we performed an optimization study to identify optimal loading and configuration of combined Fe+Cu zeolite catalyst that gives overall high
NOx removal efficiency over a broad range of temperature. Simulations suggest that the brick configuration in which Fe- brick is followed by Cu- catalyst is slightly better than dual-layer in which Fe- is coated on top of Cu- architecture. This is attributed to the diffusional limitations in the washcoat that is more pronounced in the dual-layer catalysts.
Advisors/Committee Members: Balakotaiah, Vemuri (advisor), Harold, Michael P. (advisor), Luss, Dan (committee member), Franchek, Matthew A. (committee member), Jacobson, Allan J. (committee member).
Subjects/Keywords: NOx storage; NOx reduction; Selective catalytic reduction (SCR); Pt dispersion; Multi-layered catalyst; LNT+SCR
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APA (6th Edition):
Shakya, B. M. (2013). Studies of Platinum Dispersion and Catalyst Architecture for Lean NOx Reduction. (Doctoral Dissertation). University of Houston. Retrieved from http://hdl.handle.net/10657/1194
Chicago Manual of Style (16th Edition):
Shakya, Bijesh Man. “Studies of Platinum Dispersion and Catalyst Architecture for Lean NOx Reduction.” 2013. Doctoral Dissertation, University of Houston. Accessed March 01, 2021.
http://hdl.handle.net/10657/1194.
MLA Handbook (7th Edition):
Shakya, Bijesh Man. “Studies of Platinum Dispersion and Catalyst Architecture for Lean NOx Reduction.” 2013. Web. 01 Mar 2021.
Vancouver:
Shakya BM. Studies of Platinum Dispersion and Catalyst Architecture for Lean NOx Reduction. [Internet] [Doctoral dissertation]. University of Houston; 2013. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10657/1194.
Council of Science Editors:
Shakya BM. Studies of Platinum Dispersion and Catalyst Architecture for Lean NOx Reduction. [Doctoral Dissertation]. University of Houston; 2013. Available from: http://hdl.handle.net/10657/1194
Universitat Politècnica de València
30.
Blanco Rodríguez, David.
Modelling and observation of exhaust gas concentrations for diesel engine control
.
Degree: 2013, Universitat Politècnica de València
URL: http://hdl.handle.net/10251/32666
► La Tesis Doctoral estudia la observaci'on en tiempo real de la concentraci'on en el colector de escape de 'oxidos de nitr'ogeno (NOx) y del dosado…
(more)
▼ La Tesis Doctoral estudia la observaci'on en tiempo real de la concentraci'on en el colector de escape de 'oxidos de nitr'ogeno (
NOx) y del dosado en motores
diesel sobrealimentados (¿
'1
). Para ello se combinan dos fuentes de informaci'on diferentes:
¿ Sensores capaces de proporcionar una media de dichas variables,
¿ y modelos orientados a control que estiman estas variables a partir de otras
medidas del motor.
El trabajo parte de la evaluaci'on de la precisi'on de los sensores, realizada mediante la comparaci'on de su medida con la proporcionada por equipos anal'¿ticos de
alta precisi'on, que son usados como est'andares de calibraci'on est'atica. Tambi'en se
desarrollan en la Tesis m'etodos para la calibraci'on de la din'amica del sensor; dichos m'etodos permiten identi¿car un modelo de comportamiento del sensor y revelar
su velocidad de respuesta. En general, estos sensores demuestran ser precisos pero
relativamente lentos.
Por otra parte, se proponen modelos r'apidos para la estimaci'on de
NOx y ¿
'1
.
Estos m'etodos, basados en relaciones f'¿sicas, tablas de par'ametros y una serie de
correcciones, emplean las medidas proporcionadas por otros sensores con el ¿n de
proporcionar una estimaci'on de las variables de inter'es. Los modelos permiten una
estimaci'on muy r'apida, pero resultan afectados por efectos de deriva que comprometen
su precisi'on.
Con el ¿n de aprovechar las caracter'¿sticas din'amicas del modelo y mantener
la precisi'on en estado estacionario del sensor, se proponen t'ecnicas de fusi'on de la
informaci'on basadas en la aplicaci'on de ¿ltros de Kalman (KF). En primer lugar, se
dise¿na un KF capaz de combinar ambas fuentes de informaci'on y corregir en tiempo
real el sesgo entre las dos se¿nales. Posteriormente, se estudia la adaptaci'on en tiempo
real de los par'ametros del modelo con el ¿n de corregir de forma autom'atica los
problemas de deriva asociados al uso de modelos.
Todos los m'etodos y procedimientos desarrollados a lo largo de la presente Tesis
Doctoral se han aplicado de forma experimental a la estimaci'on de
NOx y ¿
'1
. De
forma adicional, la Tesis Doctoral desarrolla aspectos relativos a la transferencia de
estos m'etodos a los motores de serie.; The dissertation covers the problem of the online estimation of diesel
engine exhaust concentrations of
NOx and '1. Two information sources are utilised:
¿ on-board sensors for measuring
NOx and '1, and
¿ control oriented models (COM) in order to predict
NOx and '1.
The evaluation of the static accuracy of these sensors is made by comparing the
outputs with a gas analyser, while the dynamics are identified on-board by perform-
ing step-like transitions on
NOx and '1 after modifying ECU actuation variables.
Different methods for identifying the dynamic output of the sensors are developed in
this work; these methods allow to identify the time response and delay of the sensors
if a sufficient data set is available. In general, these sensors are accurate but present
slow responses.
Afterwards,…
Advisors/Committee Members: Guardiola García, Carlos (advisor).
Subjects/Keywords: NOx;
Richness;
Kalman filter;
Adaptive models;
Look-up tables;
NOx sensor;
Drift;
Diesel
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Blanco Rodríguez, D. (2013). Modelling and observation of exhaust gas concentrations for diesel engine control
. (Doctoral Dissertation). Universitat Politècnica de València. Retrieved from http://hdl.handle.net/10251/32666
Chicago Manual of Style (16th Edition):
Blanco Rodríguez, David. “Modelling and observation of exhaust gas concentrations for diesel engine control
.” 2013. Doctoral Dissertation, Universitat Politècnica de València. Accessed March 01, 2021.
http://hdl.handle.net/10251/32666.
MLA Handbook (7th Edition):
Blanco Rodríguez, David. “Modelling and observation of exhaust gas concentrations for diesel engine control
.” 2013. Web. 01 Mar 2021.
Vancouver:
Blanco Rodríguez D. Modelling and observation of exhaust gas concentrations for diesel engine control
. [Internet] [Doctoral dissertation]. Universitat Politècnica de València; 2013. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10251/32666.
Council of Science Editors:
Blanco Rodríguez D. Modelling and observation of exhaust gas concentrations for diesel engine control
. [Doctoral Dissertation]. Universitat Politècnica de València; 2013. Available from: http://hdl.handle.net/10251/32666
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