Thèses sur le sujet « Emissions monitoring »
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Fan, Yibo Edward. « Condition monitoring of mechanical seals using acoustic emissions ». Thesis, University of Manchester, 2007. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.749604.
Texte intégralHonegger, Ueli. « Gas turbine combustion modeling for a Parametric Emissions Monitoring System ». Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/371.
Texte intégralKeller, Ryan A. « Studies of parametric emissions monitoring and DLN combustion NOx formation ». Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/9165.
Texte intégralDepartment of Mechanical and Nuclear Engineering
Kirby S. Chapman
The increased emissions monitoring requirements of industrial gas turbines have created a demand for less expensive emissions monitoring systems. Typically, emissions monitoring is performed with a Continuous Emissions Monitoring System (CEMS), which monitors emissions by direct sampling of the exhaust gas. An alternative to a CEMS is a system which predicts emissions using easily measured operating parameters. This system is referred to as a Parametric Emissions Monitoring System (PEMS). A review of the literature indicates there is no globally applicable PEMS. Because of this, a PEMS that is applicable to a variety of gas turbine manufacturers and models is desired. The research presented herein includes a literature review of NOx reduction techniques, NOx production mechanisms, current PEMS research, and combustor modeling. Based on this preliminary research, a combustor model based on first-engineering principles was developed to describe the NOx formation process and relate NOx emissions to combustion turbine operating parameters. A review of available literature indicates that lean-premixed combustion is the most widely-used NOx reduction design strategy, so the model is based on this type of combustion system. A review of the NOx formation processes revealed four well-recognized NOx formation mechanisms: the Zeldovich, prompt, nitrous oxide, and fuel-bound nitrogen mechanisms. In lean-premixed combustion, the Zeldovich and nitrous oxide mechanisms dominate the NOx formation. This research focuses on combustion modeling including the Zeldovich mechanism for NOx formation. The combustor model is based on the Siemens SGT-200 combustion turbine and consists of a series of well-stirred reactors. Results show that the calculated NOx is on the same order of magnitude, but less than the NOx measured in field tests. These results are expected because the NOx calculation was based only on the Zeldovich mechanism, and the literature shows that significant NOx is formed through the nitrous oxide mechanism. The model also shows appropriate trends of NOx with respect to various operating parameters including equivalence ratio, ambient temperature, humidity, and atmospheric pressure. Model refinements are suggested with the ultimate goal being integration of the model into a PEMS.
FERRE', CHIARA. « Monitoring of greenhouse gas emissions from agricultural and forest soils ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7483.
Texte intégralHeidari, Haratmeh Bardia. « New Framework for Real-time Measurement, Monitoring, and Benchmarking of Construction Equipment Emissions ». Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64345.
Texte intégralMaster of Science
Malins, Julian Paul. « The monitoring and control of specialist ceramic kiln atmospheres and emissions ». Thesis, Robert Gordon University, 1993. http://hdl.handle.net/10059/616.
Texte intégralDhamija, Tanush. « Deep Learning Architectures for time of arrival detection in Acoustic Emissions Monitoring ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/24620/.
Texte intégralXu, Jiangong Barnes Robert W. « Nondestructive evaluation of prestressed concrete structures by means of acoustic emissions monitoring ». Auburn, Ala, 2008. http://hdl.handle.net/10415/1429.
Texte intégralMeyer, Eric Todd. « Evaluation of exhaust flowrate measurement techniques for a mobile emissions monitoring system ». Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1855.
Texte intégralTitle from document title page. Document formatted into pages; contains xii, 89 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 67-68).
Bredemeyer, Stefan [Verfasser]. « Monitoring gas emissions of active volcanoes - identification of natural degassing variations and combination of volcano monitoring techniques / Stefan Bredemeyer ». Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/112814932X/34.
Texte intégralFagbeja, M. « Applying remote sensing, GIS and emissions techniques to air quality and carbon dioxide emissions measurements and monitoring in the Niger Delta ». Thesis, University of the West of England, Bristol, 2012. http://eprints.uwe.ac.uk/24727/.
Texte intégralSheppard, Victoria. « The near real time monitoring of NMHCs in tropospheric air ». Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299310.
Texte intégralBoltze, Uta. « Gas emissions relevant to waste management, through watertables in porous media ». Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307822.
Texte intégralChighine, Andrea. « Towards chemical species tomography of carbon dioxide for aviation turbine emissions ». Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29577.
Texte intégralWallius, Julia. « New concept for monitoring SO2 emissions from Tavurvur volcano in Papua New Guinea ». Thesis, Uppsala universitet, Geofysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-337344.
Texte intégralAkerstrom, Frida. « Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska : Monitoring Methane Emissions ». University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354.
Texte intégralHargreaves, K. J. « The development and application of diffusion tubes for air pollution monitoring ». Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235733.
Texte intégralCassino, Christopher Daniel. « Detection of fiber fracture in Unidirectional Fiber Reinforced Composites using an In-Plane Fiber Optic Sensor ». Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/32419.
Texte intégralMaster of Science
O'Beirne, Greg A. « Mathematical modelling and electrophysiological monitoring of the regulation of cochlear amplification ». University of Western Australia. School of Biomedical and Chemical Sciences, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0115.
Texte intégralHörmann, Christoph [Verfasser], et Ulrich [Akademischer Betreuer] Platt. « Space-based Monitoring of Volcanic Emissions Using the GOME-2 Instrument / Christoph Hörmann ; Betreuer : Ulrich Platt ». Heidelberg : Universitätsbibliothek Heidelberg, 2013. http://d-nb.info/1177148242/34.
Texte intégralDavies, Nicholas M. « The application of open-path fourier transform infrared spectrometry using resolution enhancement to gaseous emissions monitoring ». Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312528.
Texte intégralDATTA, SAURABH. « ACTIVE FIBER COMPOSITE CONTINUOUS SENSORS FOR STRUCTURAL HEALTH MONITORING ». University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1061293378.
Texte intégralGreeff, Maria. « Evaluation of the monitoring system for volatile organic compound (VOC) emissions at NATREF, South Africa / M. Greeff ». Thesis, North-West University, 2004. http://hdl.handle.net/10394/528.
Texte intégralThesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2005.
Sohn, Alexander H. 2173675. « Field Emissions of (Hydro)Chlorofluorocarbons and Methane from a California Landfill ». DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1686.
Texte intégralShakirin, Georgy. « System solution for in beam positron emission tomography monitoring of radiation therapy ». Doctoral thesis, Dresden TUDpress, 2009. http://d-nb.info/996092544/04.
Texte intégralKinrade, Joe. « Ionospheric imaging and scintillation monitoring in the Antarctic and Arctic ». Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619217.
Texte intégralWei, Nasha. « The investigation into the condition monitoring of tribological behaviour between piston ring and cylinder liner using acoustic emissions ». Thesis, University of Huddersfield, 2018. http://eprints.hud.ac.uk/id/eprint/34761/.
Texte intégralDasari, Rachana Shukthija. « Phase Locked Loop Based Signal Processing Approach for the Health Monitoring of Power Systems from their RF Emissions ». University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1545311503705164.
Texte intégralNouri, Arash. « Correlation-Based Detection and Classification of Rail Wheel Defects using Air-coupled Ultrasonic Acoustic Emissions ». Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78139.
Texte intégralMaster of Science
Kirchner, William Thomas. « Ultrasonic acoustic health monitoring of ball bearings using neural network pattern classification of power spectral density ». Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/36130.
Texte intégralMaster of Science
Stützer, Kristin. « Positron emission tomography for the dose monitoring of intra-fractionally moving targets in ion beam therapy ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-131398.
Texte intégralDie Ionenstrahltherapie (englisch: ion beam therapy, IBT) ist eine vielversprechende Behandlungsoption im Bereich der Strahlentherapie. Die charakteristischen physikalischen und biologischen Eigenschaften der Ionenstrahlen werden genutzt, um tumorkonformale Dosisverteilungen zu erzeugen. Die verbesserte Schonung des an den Tumor angrenzenden Normalgewebes und eventuell naheliegender Risikoorgane ermöglicht eine Dosissteigerung im Zielgebiet und somit potentiell höhere Tumorkontroll- und Überlebensraten. Für tiefliegende, gegenüber konventioneller Strahlung resistente, statische und gut fixierte Tumore wurden bereits beachtliche klinische Resultate erzielt. Wahrscheinlich könnten noch mehr Patienten von den Vorteilen der IBT profitieren, wenn diese auch für häufiger auftretende und intrafraktionell bewegliche Tumore uneingeschränkt nutzbar wäre. Verschiedene bewegungskompensierte Bestrahlungsmethoden wurden entwickelt und stehen zumindest unter experimentellen Bedingungen für weitere Untersuchungen am GSI Helmholtzzentrum für Schwerionenforschung (GSI) in Darmstadt zur Verfügung. Um eine sichere und präzise Dosisapplikation in der IBT zu ermöglichen, werden hohe Anforderungen an die Qualitätssicherung gesetzt. Sowohl auftretende Überdosierungen im Normalgewebe als auch Unterdosierungen im Tumor können den Therapieerfolg gefährden. Da bereits kleine, unerwartete anatomische Veränderungen, zum Beispiel durch Fehlpositionierung des Patienten, Schrumpfung des Tumors oder Schwellungen, zu erheblichen Abweichungen zwischen geplanter und applizierter Dosisverteilung führen können, gibt es Bestrebungen, die applizierte Dosis zumindest qualitativ zu verifizieren. Die Positronen-Emissions-Tomografie (PET) ist derzeit die einzige, bereits klinisch erprobte Methode für ein in vivo, in situ und nicht-invasives qualitatives Dosismonitoring. Diese Methode ist im Stande, die Autoaktivierung des bestrahlten Gewebes zu erfassen, welche aufgrund von Kernfragmentierungsprozessen entlang des Strahlweges erzeugt wird. Unter anderem werden in diesen Reaktionen instabile Nuklide erzeugt, die entsprechend ihrer Halbwertszeit unter Emission eines Positrons zerfallen. Bei der anschließenden Positron-Elektron-Annihilation werden zwei 511keV Photonen in entgegengesetzter Richtung emittiert und können mittels eines geeigneten PET-Scanners als Koinzidenzereignis detektiert werden. Die im Patienten induzierte dreidimensionale (3D) β+-Aktivitätsverteilung kann aus den gemessenen Koinzidenzen rekonstruiert werden. Ein Vergleich der gemessenen mit einer erwarteten, mittels Monte-Carlo Simulation erzeugten β+-Aktivitätsverteilung erlaubt es, Schlussfolgerungen über die tatsächlich im Patienten deponierte 3D Dosisverteilung zu ziehen. Diese Art der Datenauswertung wurde erfolgreich für die qualitative Dosisverifikation von über 440 Patienten eingesetzt, deren Tumore (vorwiegend im Kopf- und Halsbereich) an der GSI mit 12C-Ionen bestrahlt wurden. Bei der konventionellen 3D IBT-PET-Datenverarbeitung wird eine mögliche intrafraktionelle Bewegung des Zielgebietes nicht berücksichtigt und fehlerhaft rekonstruierte β+-Aktivitätsverteilungen sind die Folge. Daher werden vierdimensionale, zeitaufgelöste (4D) Rekonstruktionsalgorithmen benötigt, die für die spezielle Geometrie eines in-beam PET-Scanner adaptiert wurden und eine Kompensation der bewegungsinduzierten Artefakte ermöglichen. Im Rahmen der vorliegenden Arbeit wurde für den an der GSI installierten Doppelkopf-PET-Scanner Bastei ein 4D Maximum-Likelihood-Expectation-Maximization (MLEM) Algorithmus implementiert. Die Funktionsfähigkeit des Algorithmus sowie dessen verbesserte Reduktion von Bewegungsartefakten im Vergleich zu einem bereits vorhandenen Koregistrierungsansatz wurde anhand verschiedener Messungen mit bewegten radioaktiven Quellen und bestrahlten Phantomen sowie einer vergleichenden Simulationsstudie dargelegt. Für die Experimente wurden entsprechende Phantomgeometrien (zumeist aus Polymethylmethacrylat (PMMA)) sowie ein Bewegungstisch für reguläre eindimensionale (1D) Bewegungsmuster entworfen und gefertigt. Zudem wurde durch die erfolgreiche, quasi-statische und nahezu artefaktfreie Rekonstruktion einer rotierenden und sich damit zweidimensional bewegenden Aktivitätsverteilung die prinzipielle Anwendbarkeit des 4D MLEM Algorithmus für komplexere Bewegungsmuster gezeigt. Systematische Punktquellenmessungen mit 1D cos^2- und cos^4-förmigen Bewegungsmustern haben deutlich gemacht, dass der Bewegungseinfluss mit der gleichen Anzahl an Bewegungsphasen besser kompensiert werden kann, wenn die Bewegungsphasen entsprechend der Bewegungsamplitude anstelle der -phase unterteilt sind. In jedem Fall können aber zufriedenstellende Rekonstruktionsergebnisse erzielt werden, wenn durch geeignete Parameterwahl eine mittlere Restbewegung pro Bewegungsphase von maximal etwa der halben Größe eines Detektorkristalls eingestellt wird. Durch weitere Experimente konnte gezeigt werden, dass nach der Rekonstruktion mit dem 4D MLEM Algorithmus die relevanten Parameter für die qualitative Dosisverifikation (Teilchenreichweite, laterale Feldposition und -gradienten) zuverlässig erfasst werden können. Dies ist auch dann der Fall, wenn nur eine verminderte Anzahl an Koinzidenzereignissen, so wie sie unter klinischen Bedingungen zu erwarten ist, für die Auswertung verwendet wird. Um die gemessene β+-Aktivitätsverteilung besser zu beurteilen, sollte sie mit einer simulierten, für die bewegungskompensierte Bestrahlung erwarteten Verteilung verglichen werden und es bedarf deshalb einer 4D Version der Simulationssoftware. Diese muss die Erzeugung sowie den Zerfall der Positronenemitter unter Berücksichtigung der intrafraktionellen Bewegung simulieren und aus den gültigen Koinzidenzereignissen Listmode-Datensätze erstellen. Eine derart überarbeitet Version des Simulationsprogramms wurde für den Bastei PET-Scanner erstellt und wird in dieser Arbeit vorgestellt. Informationen über den exakten Verlauf der bewegungskompensierten Bestrahlung werden durch das Therapiekontrollsystem geliefert. Diese Informationen sowie die intrafraktionelle Bewegung werden in die Simulation realistischer β+-Aktivitätsverteilungen bzw. der zugehörigen Listmode-Datensätze einbezogen. Anhand einer präklinischen Phantom-Simulationsstudie wurde die korrekte Funktionsweise des Simulationsprogramms sowie die Notwendigkeit der zusätzlichen Parameter gezeigt. Im Gegensatz zur Datenauswertung für statische Zielvolumina bedarf es bei intrafraktioneller Bewegung gegebenenfalls zusätzlichen Aufwand, um eine Fehlinterpretation aus dem Vergleich der gemessenen und simulierten β+-Aktivitätsverteilung zu vermeiden. In der vorliegenden Arbeit wird beispielhaft gezeigt, dass sich bei fehlerhafter Bewegungskompensation die gemessene und simulierte β+-Aktivitätsverteilung einander ähneln können, obwohl die applizierte Dosisverteilung deutlich von der geplanten abweicht. Im Gegensatz dazu können auch Abweichungen zwischen Messung und Simulation auftreten, die nicht auf anatomische Veränderungen, sondern auf eine ungenaue 4D Datenverarbeitung zurückzuführen sind. Es werden Vorschläge unterbreitet, um den Prozess der 4D IBT-PET Datenauswertung zu optimieren und somit Fehlinterpretationen zu vermeiden. Die vorliegende Dissertationsschrift enthält durch die Bereitstellung der benötigten 4D Rekonstruktions- und Simulationsprogramme grundlegende Arbeiten für eine mögliche zukünftige Anwendung der 4D IBT-PET als qualitatives Dosismonitoring bei intrafraktionell bewegten Zielvolumina. Für weitere Verbesserungen des Verfahrens sind zusätzliche systematische Betrachtungen mit realistischeren, mehrdimensionalen und unregelmäßigen Bewegungsmustern notwendig. Zukünftige Untersuchungen sollten außerdem echte Bestrahlungspläne, Atemkurven sowie 4D Patienten-CT-Daten einschließen, um den erwartbaren Nutzen eines 4D IBT-PET Dosismonitorings besser abschätzen zu können
Smurzynski, Jacek. « Monitoring the Recovery from a Temporary Threshold Shift Using an Adaptive Procedure and Measurements of Spontaneous and Distortion Product Otoacoustic Emissions ». Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/2209.
Texte intégralPettersson, Niclas. « Efterlevnad av svaveldirektiven : En studie over hur landerna i svavelkontrollomradena agerar for att sakerstalla svaveldirektivens efterlevnad ». Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-25720.
Texte intégralBaldauf, Thomas [Verfasser], et Michael [Akademischer Betreuer] Köhl. « Monitoring Reduced Emissions from Deforestation and Forest Degradation (REDD+) : Capabilities of High- Resolution Active Remote Sensing / Thomas Baldauf. Betreuer : Michael Köhl ». Hamburg : Staats- und Universitätsbibliothek Hamburg, 2013. http://d-nb.info/1036729591/34.
Texte intégralBolyard, Steven Jeffrey. « Monitoring and Modeling to Estimate Hydrogen Sulfide Emissions and Dispersion from Florida Construction and Demolition Landfills to Construct Odor Buffering Distances ». Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5134.
Texte intégralID: 031001460; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: .; Title from PDF title page (viewed July 8, 2013).; Thesis (M.S.Env.E.)--University of Central Florida, 2012.; Includes bibliographical references (p. 76-77).
M.S.Env.E.
Masters
Civil, Environmental, and Construction Engineering
Engineering and Computer Science
Environmental Engineering
MAROTTA, VERONICA. « Implementation of impact mitigation measures for maritime transport : an analysis of alternative waste management practices, air emissions monitoring and GHG reduction ». Doctoral thesis, Università degli studi di Genova, 2023. https://hdl.handle.net/11567/1103474.
Texte intégralFacciotto, Nicolò. « Source differentiation and identification of acoustic emission signals by time-frequency analysis ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Trouver le texte intégralSnowden, Mareena Robinson. « Nuclear warhead monitoring : a study of photon emissions from fission neutron interactions with high explosives as a tool in arms control verification ». Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113723.
Texte intégralThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references.
Since the signing of the Nuclear Nonproliferation Treaty, the technical community has been working to develop verification options that provide confidence in the reduction or elimination of nuclear warheads, while respecting countries' requirement of limited access to national secrets. This dissertation used a simplified open-source warhead model as a vehicle to investigate the use of secondary gammas, generated passively by neutron interactions inside high explosive (HE), as a signature for the presence of a warhead-like object. Analytical calculations were done to estimate the detectability of radiative capture and inelastic scatter emissions generated within the warhead model. Results showed the emission of gammas from nitrogen, between 5-7 MeV, to be detectable above background with dwell-times exceeding 90 minutes. These calculations motivated the systematic study of the signal experimentally using surrogate materials to represent the warhead's weapons-grade plutonium and HE. The experiment did not show the expected signals. This motivated a simulation of the mock-up experiment using the radiation transport code MCNP6 to help understand the observed results. The experimental and simulation data suggest that correlated backgrounds from neutron interactions with environmental materials dominate the signal. This finding helped provide a basis for understanding the feasibility and challenges to detecting this neutron-induced gamma signal. Three sets of pulse-height spectra have been analyzed: experimental spectra that looked at the effect of the HE surrogate on the overall detected counts; simulated spectra that helped to understand the underlying contributors to the observed experimental result; and a data-MCNP6 comparison that assessed the accuracy of the simulated results. Each set contributed to the quantification of detectability for the emissions of interest. The findings suggest the passive detection of the expected high-energy gamma signal is not feasible, unless backgrounds can be better controlled. The difficulty is attributed to low solid-angle coverage of the neutron source by the melamine explosive surrogate, and competing backgrounds produced by neutron-source interactions with surrounding materials. This thesis also examined the benefits and tradeoffs of this particular verification approach by investigating the non-technical context of the verification, such as the preferences of negotiators. The tradeoffs between confidence and intrusiveness highlight the need for technical verification solutions that span the diversity of options. Factors limiting the development of warhead verification systems, from the bias of researchers to issues of classification and sensitive geometries, were discussed.
by Mareena Robinson Snowden.
Ph. D.
Leclere, Bruno. « Endommagement induit par cristallisation dans les conditions de réservoirs géologiques ». Thesis, Pau, 2021. http://www.theses.fr/2021PAUU3004.
Texte intégralVeins in geological reservoir settings are mineral-filled fractured long being associ- ated with the model of ‘crack seal’. However, some veins exhibit features that do not match with the model of ‘crack seal’ but would better fit with a ‘seal-crack’ model driven by the concept of crystallisation pressure. From this, two main experimental tests are conducted. We start with an experiment of counter diffusion to precipitate a barite front in an oolite limestone, the Lavoux limestone, and a sandstone with a shale fraction, the Adamswiller sandstone. The reacted samples are analysed via 3D X-ray microtomography, microscopy and SEM-EDS microanalysis. Although we do not ob- serve damage, we show that barite nucleation and crystallisation is linked to the pore distribution and the matrix mineral. In particular, barium interacts with clay min- erals like the smectite-chlorite complex. Ultimately, this interaction may expand the complex basal space when barite precipitates. Then salt studies for the understanding of damage induced on cultural heritage are the starting point of a new protocol with Na2SO4 and MgSO4 to be tested under isotropic confining pressure inside a triaxial cell (ENS Paris). It consists of precipitating an anhydrous salt layer in an Adamswiller sandstone. Later the anhydrous salt layer is rewetted to precipitate a more hydrated salt phase. The damage is monitored at a confining pressure up to 27 MPa with acous- tic emission, elastic wave propagation, strain gauges and 3D X-ray microtomography. These experiments emphasize the competition between salt cementation of the porous medium and salt crystallisation induced damage. The last point is confirmed by the ef- fective modeling of the elastic properties of a porous medium impregnated with sodium sulphate when it is rewetted without confining pressure
Fialová, Lada. « Hodnocení plynných výpustí ». Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217176.
Texte intégralSöderström, Hanna. « Semipermeable membrane devices as integrative tools for monitoring nonpolar aromatic compounds in air ». Doctoral thesis, Umeå University, Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-378.
Texte intégralAir pollutants pose a high risk for humans, and the environment, and this pollution is one of the major environmental problems facing modern society. Active air sampling is the technique that has been traditionally used to monitor nonpolar aromatic air pollutants. However, active high volume samplers (HiVols) require a power supply, maintenance and specialist operators, and the equipment is often expensive. Thus, there is a need to develop new, less complicated sampling techniques that can increase the monitoring frequency, the geographical distribution of the measurements, and the number of sites used in air monitoring programs. In the work underlying this thesis, the use of semipermeable membrane devices (SPMDs) as tools for monitoring gas phase concentrations of nonpolar aromatic compound was evaluated using the compound classes polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs (alkyl-PAHs) and nitrated PAHs (nitro-PAHs) as test compounds.
High wind-speeds increased the uptake and release in SPMDs of PAHs and PCBs with log KOA values > 7.9, demonstrating that the uptake of most nonpolar aromatic compounds is controlled by the boundary layer at the membrane-air interface. The use of a metal umbrella to shelter the SPMDs decreased the uptake of PAHs and PCBs by 38 and 55 percent, respectively, at high wind/turbulence, and thus reduced the wind effect. Further, the use of performance reference compounds (PRCs) to assess the site effect of wind on the uptake in SPMDs reduced the between-site differences to less than 50 percent from as much as three times differences in uptake of PCBs and PAHs. However, analytical interferences reduced the precision of some PRCs, showing the importance of using robust analytical quality control.
SPMDs were shown to be efficient samplers of gas phase nonpolar aromatic compounds, and were able to determine local, continental and indoor spatial distributions of PAHs, alkyl- PAHs and nitro-PAHs. In addition, the use of the SPMDs, which do not require electricity, made sampling possible at remote/rural areas where the infrastructure was limited. SPMDs were also used to determine the source of PAH pollution, and different approaches were discussed. Finally, SPMDs were used to estimate the importance of the gas phase exposure route to the uptake of PAHs in plants. The results demonstrate that SPMDs have several advantages compared with HiVols, including integrative capacity over long times, reduced costs, and no need of special operators, maintenance or power supply for sampling. However, calibration data of SPMDs in air are limited, and spatial differences are often only semi-quantitatively determined by comparing amounts and profiles in the SPMDs, which have limited their use in air monitoring programs. In future work, it is therefore important that SPMDs are properly sheltered, PRCs are used in the sampling protocols, and that calibrated sampling rate data, or the SPMD-air partition data, of specific compounds are further developed to make determination of time weighted average (TWA) concentrations possible.
Sears, Jill. « Spatial Distribution of Nitrogen Oxides, Benzene, Toluene, Ethylbenzene, and Xylenes in Hillsborough County, Florida : An Investigation of Impacts of Urban Forests on Ambient Concentrations of Air Pollutants Associated with Traffic ». Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4842.
Texte intégralThomas, Jacob Matthew. « Photoacoustic CO2 Detection in Biomass Cookstove Applications ». BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8740.
Texte intégralMartins, Ana Paula Garcia. « Cascas de árvores como biomonitores da poluição atmosférica de origem veicular em parques urbanos da cidade de São Paulo ». Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5144/tde-25022010-150352/.
Texte intégralThe present study was designed to characterize the area of influence of high traffic corridors by monitoring trace element concentrations on tree barks. Samples (n=98) of tree barks were collected from several tree species in five urban parks of the city of São Paulo. For controlling purposes, we collected tree barks in a rural area of Embu-Guaçu which is far from traffic or industries. Concentrations of Ba, Co, Cr, Cu, Fe, Ca, Pb, S and Zn were determined in these barks by X-ray fluorescence spectrometry. Samples from urban parks exhibited higher levels of trace elements in comparison with those from control region. Elements related to anthropogenic activities exhibited higher concentrations in tree barks at the periphery of the parks, decreasing when moving towards their centers. Areas facing the busy streets or those close to traffic lights or traffic junctions presented higher concentrations of elements in barks. In conclusion, the present study showed that measures of trace elements accumulation in tree barks within geostatistical methods can indicate areas of strong influence of vehicular pollution in the urban scene
Rix, Meike [Verfasser], Richard [Akademischer Betreuer] Bamler, Donald Bruce [Akademischer Betreuer] Dingwell et Richard (Prof Dr habil ):Trautmann Thomas [Akademischer Betreuer] Bamler. « Monitoring of volcanic sulfur dioxide emissions and estimation of the plume height using GOME-2 measurements / Meike Rix. Gutachter : Donald Bruce Dingwell ; Richard (Prof. Dr. habil.):Trautmann, Thomas Bamler. Betreuer : Richard Bamler ». München : Universitätsbibliothek der TU München, 2012. http://d-nb.info/1031512799/34.
Texte intégralAji, John Pushpam Joseph. « Wireless Air Quality and Emission Monitoring ». Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-295992.
Texte intégralMlotha, McArd Joseph. « Analysis of Land Use/Land Cover Change Impacts Upon Ecosystem Services in Montane Tropical Forest of Rwanda : Forest Carbon Assessment and REDD+ Preparedness ». Antioch University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1527773591460797.
Texte intégralSouza, Paulo Cesar de. « Desenvolvimento de um espectrômetro por absorção diferencial para medidas de poluentes na atmosfera ». Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-27052008-135818/.
Texte intégralThis work presents the results of the construction of a spectrometer using the differential optical absorption spectroscopy (DOAS) for determination of pollutants in the atmosphere. The determination and quantification of trace gas contaminations in atmosphere is possible by recording and later evaluation of characteristic absorption structures in a known path length in open atmosphere. The parts optics and electronic had been characterized and the software of command and spectral processing was developed. The system was built and tested in laboratory and vehicle emissions measures of four cars were performed. The results in vehicle emissions showed a noticeable difference between vehicles in the system of operation (hot and cold engine) by a factor ranging between 5 and 8.
Moreira, Tiana Carla Lopes. « Biomonitoramento intra-urbano da poluição de origem veicular : utilização da casca de árvore na identificação de fontes de poluição atmosférica ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/5/5144/tde-08042016-160957/.
Texte intégralDue to the heterogeneous dispersion of air pollution, it is important to understand sources of local pollution to assess impacts on human health. Chemical elements, especially metals, can affect human health, causing genotoxic effects, cancer induction, and damage in the immune and neurological systems. Some elements are considered markers of vehicle emissions. Consequently it is of great interest to evaluate if there is a relationship between the vehicular traffic flow and deposition of elements measured using the biomonitoring technique. In this study, tree barks from 171 sampling sites in the inner city of São Paulo were collected. The chemical elements (Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, Pb, Rb, S, Sr and Zn) were determined by the energy dispersive x-ray fluorescence (EDXRF) spectrometry. The principal component analysis (PCA) statistical technique was applied to the analytical results in order to identify the origin of element pollutants. The results indicated that major source of air pollution is due to vehicular emission derived mainly from wear processes and road dust resuspension (characterized by Al, Ba, Cu, Fe, Mn and Zn), which was explained by 27.1 % of the variance, followed by cement from building constructions and road pavements (14.8 %), sea salt (11.6 %) and wood burning (10 %) at São Paulo inner city. The algorithm called positive matrix factorization (PMF) likewise used to identify the air pollution sources showed that the vehicular emission is also the main source of atmospheric pollution. We also verified that the elements related to vehicular emission presented different concentrations at different sampling sites of the same street, which might be possible to identify a new street classification according to the elemental concentration. The spatial distribution maps of element concentrations were obtained to evaluate the different levels of pollution on streets and avenues. Results indicated that biomonitoring technique can be applied to evaluate dispersion of air pollution
Eftekharnejad, Babak. « Condition monitoring of gearboxes using acoustic emission ». Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6780.
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