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Dissertations / Theses on the topic 'Lean hydrogen'

Author: Grafiati

Published: 29 March 2025

Last updated: 31 July 2025

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1

Topinka, Jennifer A. (Jennifer Ann) 1977. "Knock behavior of a lean-burn hydrogen-enhanced engine concept." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/34351.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.<br>Includes bibliographical references (p. 89-91).<br>Experiments to identify the knock trends of lean gasoline-air mixtures, and such mixtures enhanced with hydrogen (H2) and carbon monoxide (CO), were performed on a single-cylinder research engine with boosting capability. The experimental method used to investigate knock trends consisted of determining the octane number (ON) of the primary reference fuel (mixture of isooctane and n-heptane) supplied to the engine that just produced audible knock. Al

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2

Goldwitz, Joshua A. (Joshua Arlen) 1980. "Combustion optimization in a hydrogen-enhanced lean burn SI engine." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/27061.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.<br>Includes bibliographical references (p. 95-97).<br>Lean operation of spark ignition (SI) automotive engines offers attractive performance incentives. Lowered combustion temperatures inhibit NO[sub]x pollutant formation while reduced manifold throttling minimizes pumping losses, leading to higher efficiency. These benefits are offset by the reduced combustion speed of lean mixtures, which can lead to high cycle-to-cycle variation and unacceptable engine behavior characteristics. Hydrogen-enhancement

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3

Sykes, David Michael. "Design and Evaluation of a Lean-Premixed Hydrogen Injector with Tangential Entry in a Sector Combustor." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31722.

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Hydrogen use in a gas turbine engine has many benefits. Chief among these is the elimination of carbon based emissions. The only products and emissions from the combustion process are water vapor and oxides of nitrogen (NOx). However due to the lower flammability limit of hydrogen, it can be burned at much lower equivalence ratios that typical hydrocarbon fuels, and thus reducing the emissions of NOx. Multiple efforts have been made for the design of premixing injectors for gaseous hydrocarbon fuels, but very few attempts have been made for hydrogen. <p> To this end a premixing hydrogen in

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4

Ivanic, Å½iga 1978. "Predicting the behavior of a lean-burn hydrogen-enhanced engine concept." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17932.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.<br>Includes bibliographical references (p. 90-91).<br>(cont.) Lean operation of a spark ignition (SI) internal combustion engine (ICE) offers attractive performance incentives. Lowered combustion temperatures inhibit formation of nitrogen oxides (NOx), while reduced intake manifold throttling minimizes pumping losses leading to higher efficiency. These benefits are offset by the reduced combustion speed of lean mixtures, which can lead to high cycle-to-cycle variation and unacceptable engine behavior c

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5

Ross, Martin C. Shepherd J. E. "Lean combustion characteristics of hydrogen-nitrous oxide-ammonia mixtures in air /." Diss., Pasadena, Calif. : California Institute of Technology, 1997. http://resolver.caltech.edu/CaltechETD:etd-01182008-143226.

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6

Villarreal, Daniel Christopher. "Digital Fuel Control for a Lean Premixed Hydrogen-Fueled Gas Turbine Engine." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/34974.

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Hydrogen-powered engines have been gaining increasing interest due to the global concerns of the effects of hydrocarbon combustion on climate change. Gas turbines are suitable for operation on hydrogen fuel. This thesis reports the results of investigations of the special requirements of the fuel controller for a hydrogen gas turbine. In this investigation, a digital fuel controller for a hydrogen-fueled modified Pratt and Whitney PT6A-20 turboprop engine was successfully designed and implemented. Included in the design are safety measures to protect the operating personnel and the engine. A

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7

Perry, Matthew Vincent. "An Investigation of Lean Premixed Hydrogen Combustion in a Gas Turbine Engine." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/43532.

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As a result of growing concerns about the carbon emissions associated with the combustion of conventional hydrocarbon fuels, hydrogen is gaining more attention as a clean alternative. The combustion of hydrogen in air produces no carbon emissions. However, hydrogen-air combustion does have the potential to produce oxides of nitrogen (NOx), which are harmful pollutants. The production of NOx can be significantly curbed using lean premixed combustion, wherein hydrogen and air are mixed at an equivalence ratio (the ratio of stoichiometric to actual air in the combustion process) significantly

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8

Farina, Jordan Thomas. "Conversion of a Gas Turbine Engine to Operate on Lean-Premixed Hydrogen-Air: Design and Characterization." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/31067.

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The continued use of fossil fuels along with a rise in energy demand has led to increasing levels of carbon emissions over the past years. The purpose of this research was to design a lean premixed hydrogen fuel system that could be readily retrofit into an existing gas turbine engine to provide a clean renewable energy solution to this growing problem. There were major hurdles that had to be overcome to develop a hydrogen fuel system that would be practical, stable, and would fit into the existing space. High flame temperatures coupled with high flame speeds are major concerns when switchin

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9

Speth, Raymond L. 1981. "Effects of curvature and strain on a lean premixed methane-hydrogen-air flame." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35640.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.<br>Includes bibliographical references (leaves 74-77).<br>The elemental flame is a subgrid model for turbulent combustion, parameterized by time-varying strain rate and curvature. This thesis develops the unsteady one-dimensional governing equations for the elemental flame incorporating detailed chemical kinetics and transport and a robust and efficient numerical method for solving the governing equations. Hydrogen enrichment of some hydrocarbon fuels has been shown to improve stability and extend flam

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10

Coleman, Marc David. "Catalytic reduction of nitrogen monoxide using hydrogen at low temperatures under lean burn conditions." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246453.

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11

Ayala, Ferran A. (Ferran Alberto) 1976. "Combustion lean limits fundamentals and their application to a SI hydrogen-enhanced engine concept." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/38262.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.<br>Includes bibliographical references (p. 197-199).<br>Operating an engine with excess air, under lean conditions, has significant benefits in terms of increased engine efficiency and reduced emissions. However, under high dilution levels, a lean limit is reached where combustion becomes unstable, significantly deteriorating drivability and engine efficiency, thus limiting the full potential of lean combustion. Due to hydrogen's high laminar flame speed, adding a hydrogen-rich mixture with gasoline

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12

Homitz, Joseph. "A Lean-Premixed Hydrogen Injector with Vane Driven Swirl for Application in Gas Turbines." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/36334.

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Hydrogen, as an alternative to conventional aviation fuels, has the potential to increase the efficiency of a gas turbine as well as reduce emissions of greenhouse gases. In addition to significantly reducing the number of pollutants due to the absence of carbon, burning hydrogen at low equivalence ratios can significantly reduce emissions of oxides of nitrogen (NOx). Because hydrogen has a wide range of flammability limits, fuel lean combustion can take place at lower equivalence ratios than those with typical hydrocarbon fuels. <p> Numerous efforts have been made to develop gas turbine fu

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13

Karkow, Douglas W. "Combustion instabilities: an experimental investigation on the effects of hydrogen in a lean premixed combustor." Thesis, University of Iowa, 2012. https://ir.uiowa.edu/etd/2911.

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14

Tully, Edward J. (Edward Joseph) 1975. "Lean-burn characteristics of a gasoline engine enriched with hydrogen from a plasmatron fuel reformer." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/34349.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.<br>Includes bibliographical references (leaves 75-76).<br>If a small amount of hydrogen is added to a gasoline fueled spark ignition engine the lean limit of the engine can be extended. Lean running engines are inherently more efficient, and have the potential for significantly lower NOx emissions. Hydrogen addition reduces the combustion variability. In this engine concept supplemental hydrogen is generated on-board the vehicle by diverting a small fraction of the gasoline to a plasmatron where it is

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15

Zhang, Qingguo. "Lean blowoff characteristics of swirling H2/CO/CH4 Flames." Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22641.

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This thesis describes an experimental investigation of lean blowoff for H2/CO/CH4 mixtures in a swirling combustor. This investigation consisted of three thrusts. The first thrust focused on correlations of the lean blowoff limits of H2/CO/CH4 mixtures under different test conditions. It was found that a classical Damköhler number approach with a diffusion correction could correlate blowoff sensitivities to fuel composition over a range of conditions. The second part of this thesis describes the qualitative flame dynamics near blowoff by systematically characterizing the blowoff phenomeno

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16

Kaufman, Kelsey Leigh. "Effect of hydrogen addition and burner diameter on the stability and structure of lean, premixed flames." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4661.

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Low swirl burners (LSBs) have gained popularity in heating and gas power generation industries, in part due to their proven capacity for reducing the production of NOx, which in addition to reacting to form smog and acid rain, plays a central role in the formation of the tropospheric ozone layer. With lean operating conditions, LSBs are susceptible to combustion instability, which can result in flame extinction or equipment failure. Extensive work has been performed to understand the nature of LSB combustion, but scaling trends between laboratory- and industrial-sized burners have not been est

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17

Reichel, Thoralf G. [Verfasser], Christian Oliver [Akademischer Betreuer] Paschereit, Christian Oliver [Gutachter] Paschereit, Yeshayahou [Gutachter] Levy, and Arvind [Gutachter] Rao. "Flashback prevention in lean-premixed hydrogen combustion / Thoralf G. Reichel ; Gutachter: Christian Oliver Paschereit, Yeshayahou Levy, Arvind Rao ; Betreuer: Christian Oliver Paschereit." Berlin : Technische Universität Berlin, 2017. http://d-nb.info/1156185807/34.

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18

山本, 和弘, Kazuhiro YAMAMOTO, 義昭小沼 та Yoshiaki ONUMA. "希薄燃焼に及ぼす水素添加の効果 (第3報, 反応機構に着目した管状火炎の数値計算)". 日本機械学会, 1999. http://hdl.handle.net/2237/9326.

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19

山本, 和弘, Kazuhiro YAMAMOTO, 昌幸丸山, Masayuki MARUYAMA, 義昭小沼 та Yoshiaki ONUMA. "希薄燃焼に及ぼす水素添加の効果". 日本機械学会, 1998. http://hdl.handle.net/2237/9318.

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20

山本, 和弘, Kazuhiro YAMAMOTO, 昌幸丸山, Masayuki MARUYAMA, 義昭小沼 та Yoshiaki ONUMA. "希薄燃焼に及ぼす水素添加の効果 (第2報, 管状火炎の特性と輸送過程に及ぼす回転強さの影響)". 日本機械学会, 1999. http://hdl.handle.net/2237/9322.

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21

Katzy, Peter [Verfasser], Thomas [Akademischer Betreuer] Sattelmayer, Thomas [Gutachter] Sattelmayer, and Marco K. [Gutachter] Koch. "Combustion Model for the Computation of Flame Propagation in Lean Hydrogen-Air Mixtures at Low Turbulence / Peter Katzy ; Gutachter: Thomas Sattelmayer, Marco K. Koch ; Betreuer: Thomas Sattelmayer." München : Universitätsbibliothek der TU München, 2021. http://d-nb.info/1229620877/34.

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22

Katzy, Peter Verfasser], Thomas [Akademischer Betreuer] Sattelmayer, Thomas [Gutachter] Sattelmayer, and Marco K. [Gutachter] [Koch. "Combustion Model for the Computation of Flame Propagation in Lean Hydrogen-Air Mixtures at Low Turbulence / Peter Katzy ; Gutachter: Thomas Sattelmayer, Marco K. Koch ; Betreuer: Thomas Sattelmayer." München : Universitätsbibliothek der TU München, 2021. http://d-nb.info/1229620877/34.

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23

Ruel, Fiona. "Contribution électrochimique à l’étude de la corrosion sous contrainte des aciers inoxydables lean duplex en milieu purement chloruré et sous présence de sulfure d’hydrogène." Thesis, Saint-Etienne, EMSE, 2014. http://www.theses.fr/2014EMSE0743/document.

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Les aciers inoxydables lean duplex, à faible teneur en nickel et sans molybdène, représentent une alternative économique pour les usines de dessalement et l’industrie pétrolière. Celles-ci ont la particularité d’être exposées à des milieux très agressifs dont la présence de chlorure, de sulfure d’hydrogène, de hautes températures ou encore d’acides peut provoquer des phénomènes de fissuration sous contrainte.Cette étude est divisée en deux parties, la première se consacre aux milieux purement chlorurés et la seconde aux milieux contenant du sulfure d’hydrogène. Dans les deux parties, la compré

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24

Saffari, Yasaman. "Leak Test on High-Speed Separator." Thesis, KTH, Kemiteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-90477.

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High speed separators from Alfa Laval are widely in use for processing flammable and non-flammable liquids. The following work is focusing on the case of non-flammable liquid as the process liquid in case the working area around the equipment may contain quantities of explosive gases. As stated by Alfa Laval documentation, the major risk is leaking of the explosive atmosphere into the separator from the surrounding environment which may result in producing zone 1 or zone 2 of hazardous area classification. Zone 1: Area in which an explosive gas-air mixture is likely to occur for short periods

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25

De, Santis Donato. "Hydrogen reduction of lead from Kelex 100." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66077.

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26

Mohammadabadi, Ali Shafiei. "Hydrogen‐induced damage of lead‐zirconate‐titanate (PZT)." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44320.

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Lead-Zirconate-Titanate Pb(Zr,Ti)O₃ (PZT) based actuators are evaluated by automotive industry for advanced fuel-injection systems, including hydrogen injection. However, hydrogen can have deleterious effect on the PZT's functionality and properties. The general objective of this work is to study the interactions between PZT and hydrogen. The results of long-term (200-1200 hours) high-pressure (10 MPa) hydrogen exposure on the PZT microstructure show that hydrogen has only superficial effects on the microstructure of bare PZT. However, when an electrode is attached to PZT, the hydrogen damage

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27

Villenave, Nicolas. "Étude expérimentale des propriétés fondamentales de la combustion de l'hydrogène pour des applications de propulsion." Electronic Thesis or Diss., Orléans, 2025. http://www.theses.fr/2025ORLE1001.

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En vue d'atteindre la neutralité carbone d'ici 2050, l’Union européenne envisage l'hydrogène comme un vecteur énergétique prometteur afin de réduire la consommation des ressources fossiles. Alors que les piles à combustible et les véhicules électriques occupent déjà une place importante dans la décarbonation du secteur des transports, l'hydrogène est également considéré comme une alternative aux carburants conventionnels pour les véhicules lourds. Toutefois, de nombreux obstacles liés aux propriétés physico-chimiques ainsi qu’à la combustion pauvre en hydrogène sont encore à l’étude : appariti

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28

Halici, Safak. "Development Of Lead Alloys For Valve-regulated Lead-acid (vrla) Batteries." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612422/index.pdf.

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In this study, Mg, Sn, Cd, Bi and Sb containing, five binary, three ternary and two quaternary different alloys to be used in a Valve-Regulated Lead-Acid (VRLA) batteries have been studied in terms of their mechanical and electrochemical properties. The investigated properties are hardness, passivity, corrosion rate, hydrogen gassing and the conductivity of the passive film. All electrochemical tests were carried out in 3.75 M H2SO4 solution by using open-circuit potential, anodic polarization, polarization resistance measurement and gas collection techniques. The results showed that while the

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29

Ball, Allen Joseph. "Investigation of gaseous hydrogen leak detection using Raman scattering and laser-induced breakdown spectroscopy." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010545.

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30

Saini, Alpna. "An investigation of the cause of leak formation in palladium composite membranes." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-133412/.

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31

Barakat, Waël. "Chimie de coordination supramoléculaire avec des porphyrines à anses greffées en positions méso 5,10." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S049.

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Ce travail de thèse traite de la synthèse de porphyrines à une ou deux anses (6, 11, 8i and 14i) greffées sur les positions méso adjacentes 5,10 et 15,20 et portant une fonction acide carboxylique suspendue avec ou sans un autre groupement fonctionnel (cyano, pyridine) en position alpha. Cette conformation génère une flexibilité de l'anse avec deux positions clairement identifiées de l'acide carboxylique (intérieure/extérieure). Ainsi la synthèse et la caractérisation des composés sont discutées en détails puis la coordination des ligands 6, 11, et 8i avec les métaux Zn(II), Hg(II), Pb(II) et

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32

Vempati, Venkata Surya Raghuram. "Remote detection of hydrogen leak using Nd:YAG pulsed laser induced dual line detection Rayleigh light scattering." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0008640.

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33

Deshpande, Sameer Arun. "DIMESIONALITY ASPECTS OF NANO MICRO INTEGRATED METAL OXIDE BASED EARLY STAGE LEAK DETECTION ROOM TEMPERATURE HYDROGEN SENSOR." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2131.

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Detection of explosive gas leaks such as hydrogen (H2) becomes key element in the wake of counter-terrorism threats, introduction of hydrogen powered vehicles and use of hydrogen as a fuel for space explorations. In recent years, a significant interest has developed on metal oxide nanostructured sensors for the detection of hydrogen gas. Gas sensors properties such as sensitivity, selectivity and response time can be enhanced by tailoring the size, the shape, the structure and the surface of the nanostructures. Sensor properties (sensitivity, selectivity and response time) are largely modulate

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34

Can, Mukaddes. "Hydrogen Generation From Conventional Fuels Over Mesoporous Mixed Oxide Catalysts Under Time Interrupted Reaction Conditions." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12614520/index.pdf.

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In this study, catalytic activity of the Co and/or Pb-SBA-15 mesoporous catalysts in methane partial oxidation reaction was investigated. By using sol-gel, incipient wetness impregnation and post grafting method, SBA-15 samples are incorporated with Co and/or Pb at different weight loadings to provide a controlled geometry in nanometer scale. The characterization of the synthesized samples was done by XRD, N2 adsorption isotherms, FTIR, TEM images, Raman and XPS analysis. In the present study also, gas phase methane partial oxidation modeling and the synthesizing of mesoporous SBA-15 silica w

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35

Bates, Benjamin R. "Within Lake Spatial Variability of Long-chain n-alkanes and their Hydrogen Isotopic Compositions Adirondack Mountains, NY." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535373859284956.

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36

Rogoff, Eric Brian 1960. "Characterization of water interaction with the Apache Leap Tuff, Superior, Arizona, using stable isotopes of oxygen and hydrogen." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/191988.

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Alteration of rock by water is observed in all levels of the Apache Leap Tuff, Superior, Arizona. Possible alteration conditions range from hydrothermal circulation after eruption of the tuff to percolation of low temperature modern water. This study uses stable isotopes of oxygen and hydrogen in matrix phenocrysts and whole rocks to determine temperature and timing of alteration, and the extent of water-rock interaction at progressive distances from fractures. Data indicate low temperatures (20 to 30°C) of water-rock interaction. Water/rock ratios increase stratigraphically upward. Water/rock

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37

Tierney, Jessica E., Francesco S. R. Pausata, and Peter B. deMenocal. "Rainfall regimes of the Green Sahara." AMER ASSOC ADVANCEMENT SCIENCE, 2017. http://hdl.handle.net/10150/622881.

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During the "Green Sahara" period (11,000 to 5000 years before the present), the Sahara desert received high amounts of rainfall, supporting diverse vegetation, permanent lakes, and human populations. Our knowledge of rainfall rates and the spatiotemporal extent of wet conditions has suffered from a lack of continuous sedimentary records. We present a quantitative reconstruction of western Saharan precipitation derived from leaf wax isotopes in marine sediments. Our data indicate that the Green Sahara extended to 31 degrees N and likely ended abruptly. We find evidence for a prolonged "pause" i

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Suh, Yeon Jee. "Leaf Wax Stable Isotopes as Paleovegetation and Paleohydrologic Proxies: From a Modern Calibration Study to a Paleoclimate Application." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1512045032087257.

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SENNA, ROQUE M. de. "Desenvolvimento e demonstração de funcionamento de um sistema híbrido de geração de energia elétrica, com tecnologia nacional, composto por módulo de células a combustível tipo PEMFC e acumulador chumbo ácido." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10121.

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Made available in DSpace on 2014-10-09T12:35:00Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T13:59:32Z (GMT). No. of bitstreams: 0<br>Tese (Doutoramento)<br>IPEN/T<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Möller, Lena [Verfasser]. "Funktionalisierung von Oberflächen und Hyaluronsäure-basierte Hydrogele für die Anwendung in der regenerativen Medizin / Lena Möller." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2012. http://d-nb.info/1023627116/34.

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Mittlmeier, Lena [Verfasser], and Matthias [Akademischer Betreuer] Schieker. "Evaluation der Wirkung eines BMP-7-beladenen Hydrogels im murinen intramedullären Injektionsmodell / Lena Mittlmeier ; Betreuer: Matthias Schieker." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/1182899617/34.

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42

Bubnová, Kateřina. "Využití nízkotlakého plazmatu pro čistění olověných archeologických nálezů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449329.

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This diploma thesis builds on my bachelor thesis, which was focused on the application of low-pressure hydrogen plasma and argon-hydrogen plasma on layers of corrosion products. According to results of the experiments, an appropriate temperature for plasma chemical treatment of lead samples was detected. However, the process of corrosion removal through plasma chemical treatment needs to be further optimized to prevent potential damage to the original historical artefacts. Optimization of the treatment process is therefore the main subject of this work’s research. The model samples with artifi

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Shaw, Caitlin H. "A Preliminary Investigation of Treating Metal Pollutants in Water by Slow-Release Hydrogen Peroxide." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1493820099202382.

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44

Deloule, Etienne. "Analyses isotopiques à l'échelle intra-cristalline : une contribution à l'étude des systèmes géologiques." Vandoeuvre-les-Nancy, INPL, 1991. http://docnum.univ-lorraine.fr/public/INPL_T_1991_DELOULE_E.pdf.

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La composition isotopique du Plomb a été mesurée sur des lessivages progressifs des minéraux de sulfures des gisements métallifères de la ceinture archéenne de l'Abitibi (Québec). La signature isotopique des gisements en milieu sédimentaire montre que les métaux proviennent d'une croute continentale antérieure à la ceinture de roches vertes, âgée de 2,7 milliards d'années. Les minéralisations associées au volcanisme résultent d'un mélange entre cette source crustale et une source mantellique. L'analyse isotopique à la sonde ionique du plomb et du soufre des galènes de Tristate et du Viburnum t

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DIAS, André Luís de França. "Perfil fisiológico e bioquímico de três variedades de cana-de-açúcar (Saccharum spp.) durante a aclimatização." Universidade Federal Rural de Pernambuco, 2014. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4723.

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Submitted by (edna.saturno@ufrpe.br) on 2016-06-14T15:47:03Z No. of bitstreams: 1 Andre Luis de Franca Dias.pdf: 1058700 bytes, checksum: 0141cbefc140d89e9bd8891c383caa9b (MD5)<br>Made available in DSpace on 2016-06-14T15:47:03Z (GMT). No. of bitstreams: 1 Andre Luis de Franca Dias.pdf: 1058700 bytes, checksum: 0141cbefc140d89e9bd8891c383caa9b (MD5) Previous issue date: 2014-02-14<br>The cultivation of sugarcane in Brazil has notoriety for contributing significantly to the economy. The micropropagation is a tool for tissue culture plants to produce on a large scale genetically identica

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Peigat, Laurent. "Modélisation d'un joint viscoplastique pour la filière hydrogène." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2012. http://pastel.archives-ouvertes.fr/pastel-00756297.

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L'Electrolyse de la Vapeur d'eau à Haute Température (EVHT) est l'un des procédésde production d'hydrogène les plus prometteurs. Dans l'optique d'une économie del'hydrogène produit par EVHT, de nombreux verrous restent à lever. L'un d'entre euxporte sur l'étanchéité. En effet, dans un EVHT, la gestion des gaz est primordiale. Ilfaut pouvoir gérer et prévoir dans le temps le comportement des joints afin d'éviter unedégradation des performances. Or, en EVHT, les températures de fonctionnement sontélevées (classiquement autour de 800 °C), des phénomènes de fluage ou de relaxationapparaissent, le

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Tsvetkova, Galina Valeryevna. "An autonomous long-term fast reactor system and the principal design limitations of the concept." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/36.

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The objectives of this dissertation were to find a principal domain of promising and technologically feasible reactor physics characteristics for a multi-purpose, modular-sized, lead-cooled, fast neutron spectrum reactor fueled with an advanced uranium-transuranic-nitride fuel and to determine the principal limitations for the design of an autonomous long-term multi-purpose fast reactor (ALM-FR) within the principal reactor physics characteristic domain. The objectives were accomplished by producing a conceptual design for an ALM-FR and by analysis of the potential ALM-FR performance character

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Ross, Martin C. "Lean combustion characteristics of hydrogen-nitrous oxide-ammonia mixtures in air." Thesis, 1997. https://thesis.library.caltech.edu/227/1/Ross_mc_1997.pdf.

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We report experimental studies on the combustion of lean hydrogen-nitrous oxide-ammonia-air mixtures. This project is in support of the waste tank safety assessment for the storage facility at Hanford, WA. This study focuses on combustion limits, pressure histories, and flame speeds of flammable gas mixtures characteristic of this facility. A facility was constructed to study the lean combustion characteristics of mixtures containing ammonia. This facility consists of a gas-handling system, a remotely-controlled 400-liter pressure vessel, a vacuum system capable of pumping and disposing of

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Schlup, Jason Robert. "Numerical Investigations of Transport and Chemistry Modeling for Lean Premixed Hydrogen Combustion." Thesis, 2018. https://thesis.library.caltech.edu/10991/1/schlup_jason_2018.pdf.

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<p>The use of hydrogen as a fuel for power generation applications has been suggested as an additive to, or replacement of, hydrocarbon fuels. The safety of hydrogen combustion has also received recent attention due to nuclear power plant disasters and the rise of hydrogen refuelling stations. In these uses and scenarios, lean hydrogen--air flames are prone to thermo-diffusive instabilities which can be dangerous to equipment and personnel. These instabilities are heavily influenced by two mechanisms: transport properties (e.g., diffusion) and chemical species production rates. This thesis

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Hernandez, Perez Francisco Emanuel. "Subfilter Scale Modelling for Large Eddy Simulation of Lean Hydrogen-enriched Turbulent Premixed Combustion." Thesis, 2011. http://hdl.handle.net/1807/29744.

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Hydrogen (H2) enrichment of hydrocarbon fuels in lean premixed systems is desirable since it can lead to a progressive reduction in greenhouse-gas emissions, while paving the way towards pure hydrogen combustion. In recent decades, large-eddy simulation (LES) has emerged as a promising tool to computationally describe and represent turbulent combustion processes. However, a considerable complication of LES for turbulent premixed combustion is that chemical reactions occur in a thin reacting layer at small scales which cannot be entirely resolved on computational grids and need to be modelled.

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