Dissertations / Theses: 'Line emission study'

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Robinson, A. "A study of emission line variability in active galactic nuclei." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356433.

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Jarad, Majeed M. "A spectroscopic study of some early-type emission-line stars." Thesis, University of St Andrews, 1986. http://hdl.handle.net/10023/14418.

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Spectroscopic observations of 18 of the brighter Be and 0e stars in the Northern Hemisphere have been presented in this project. About 900 spectrograms were secured and measured using the more objective numerical technique (REDUCE and VCROSS) to obtain as many accurate radial velocities as possible for these stars. The analysis of these measurements has demonstrated clearly, that most of these early-type stars are indeed variable in radial velocity, while a real periodicity in the radial velocities of some of the programme stars is found. The long-term periodicities were attributed to the binary nature, while the short ones could be ascribed to the pulsation phenomenon. Orbital elements are determined for four newly discovered binary systems, and improved orbits are determined for four known binaries. Five other stars display short time-scale periodicity (less than 1.5 days) attributable to radial or non-radial pulsation, whilst three variables show little evidence for periodicity. Only two stars are found to have constant radial velocities. A brief summary of the properties of Be stars and all the available models to explain the Be phenomenon is presented in chapter one. Chapter two contains a brief description of the observing equipment and the techniques used. The reasons for selecting the programme stars are given in the same chapter. A complete explanation of the measuring technique used in this investigation is given in chapter three. In chapter four, all the analyses and the results for each star are given individually, while a discussion of previous work on these stars appears in the relevant sections. The final chapter contains a discussion of the results from this study together with an analysis of the energy distributions of the programme stars, compiled by the author from published fluxes and photometry from the ultraviolet to the infra-red parts of the electromagnetic spectrum. Some consideration of future work to be done on these types of stars is also given.

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Younes, George. "Complete X-ray study of low ionization nuclear emission line regions showing broad Hα emission (LINER 1s) and their spectral energy distribution." Strasbourg, 2011. http://www.theses.fr/2011STRA6088.

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Cette thèse concerne l'étude des noyaux actifs de galaxies (AGN) de faible luminosité dans l'univers proche, principalement peuplé par les "Low Ionization Nuclear Emission-line Regions" (LINERs) galaxies. L'étude a été basée sur un échantillon de LINERls montrant une détection robuste de raie large en émission Halpha, une propriété typique des AGN lumineux de type 1. J'ai étudié le mode d'accrétion et les processus radiatifs de ces LINER 1 s en examinant leurs propriétés en rayons X et multi-Iongueurs d'onde (distribution spectrale d'énergie, SED), et en les comparant t celles des AGN lumineux (Seyferts et quasars) et des binaires X. Les différences des propriétés en rayons X de cet échantillon par rapport aux AGN lumineux (variabilité sur des courtes échelles de temps rare, absence de la raie d'émission Fe Kalpha t 6. 4 keV, et anticorrélation de l'indice de la loi de puissance en rayons X avec le rapport d'Eddington) indiquent probablement la présence d'un mode d'accrétion et radiatif différent entre ces deux classes d'objets, c. -t. -d. Un processus radiatif RIAF/jet pour les LINER Is. A une luminosité en rayons X donnée, la SED de ces LINER 1 s, construite avec des flux simultanées en rayons X et UV, (1) ressemble dans le domaine radio t celles des AGN radio-émettrices (rapport du flux radio sur rayons X, =-1. 17), et (3) montre une luminosité bomométrique d'au moins deux ordres de grandeur plus faible que les AGN lumineuses. Ces propriétés multi-Iongueurs d'onde de ces LINERls sont également probablement compatibles avec un processus radiatif RIAF/jet
This thesis focuses on the faint end of the active galactic nuclei (AGN) luminosity function in the nearby universe, mainly populated by AGN-powered Low Ionization Nuclear Emission-line Regions (LINERs). The study was based on a LINERls sample anSllyzed showing a definite detection of a broad Halpha emission, a typical property of luminous type 1 AGN. 1 have investigated the accretion mode and radiative processes ofthese AGN-powered LINERls based on their X-ray and multi-wavelength (spectral energy distribution, SED) properties, and 1 have compared them to those ofluminous AGN (Seyfert galaxies and quasars) and X-ray binaries. The dissimilarities in the X-ray properties ofthis sample compared to luminous AGN (rare short timescale variability, no Fe Kalpha emission line at 6. 4 keV, ~nd the anticorrelation of the X-ray powerlaw index with the Eddington ratio) point toward probably a different accretion and radiative process in these two classes, i. E. A RIAF/jet radiative process in LINER ls. The SED ofthese LINER ls with simultaneous UV and X-ray fluxes, at a given X-ray luminosity, (1) resembles the SED ofradio-loud AGN in the radio band (mean radio-to-X-ray flux ratio, =-1. 17), and (3) displays bolometric luminosity of at least two orders of magnitude lower than luminous AGN. Again, the multi-wavelength properties ofthese LINERls are most likely consistent with a RIAF/jet radiative rocess

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4

Holt, Joanna. "An observational study of the emission line systems in compact radio sources." Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419256.

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Ferreira, João Pedro de Jesus. "A broad-band study of the evolving emission-line properties of galaxies." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/28717.

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This thesis describes a new approach to the study of high-redshift star-formation and its environments that can be applied to large high-redshift surveys. Instead of relying on spectroscopy or narrow-band photometry to study galaxy line emission in detail, the properties of large emission line galaxy (ELG)populations are estimated from broadband photometry by measuring colour-residuals against colours drawn from a set of line-free stochastic burst models-based on (Bruzual & Charlot, 2003). Simulated star-formation histories drawn from semi-analytic and adaptive-mesh-refinement codes were converted into mock galaxy colours, but neither could-span the range of observed galaxy colours at high redshift. Instead, an existing set of exponentially declining star-formation models with stochastic bursts was used, because it closely spanned the range in observed galaxy colours in the bandsthat were line-free at each redshift. Small colour offsets were measured between the models and the observations, corresponding to the equivalent widths (EWs)of Hα, [OIII] and [OII]. In this way, I measure the rest-frame Equivalent Widths of the Hα, [OIII]and [OII] emission lines as they are redshifted through all filters from CANDELS(near-continuous U to 4.5μm coverage) for a large sample of galaxies from z=0.1up to z=5. This approach relies solely on the line-free models, a set of existing reliable photometric redshifts, and a colour cut (B−K < 2 or equivalent) to select only the dust-free young objects (the majority of identified emission-line galaxies). Once correctly identified, I apply this method to the CANDELS-UDS photometry to characterise the properties of Emission-Line Galaxies (ELGs) through these lines. I find that in this sample the Hα and [OIII] ELG fraction with EW > 150Årises from < 5% at z < 1 up to 40% at z > 2. The co-moving ELG density rises from 5 to 30 ×10 −4 /Mpc −3 at z=2.3. The evolution of median Hα EW with redshift is consistent with results from HiZELS and 3D-HST yielding median EW ∼ M 0.25 (1+z) 1.75 up to z=2.3, from which it departs to values of 450Å atz=4.3. [OIII] remains weaker than Hα for z < 3 and matches its values above that redshift. [OIII] also displays a larger fraction of extreme EWs than Hα. [OII], while correctly identified, never becomes as extreme as the other two lines lines, even when corrected for the evolving continuum. This is evidence of an increasing [OIII]/[OII] ratio with increasing z through-out this sample. While these results agree with spectroscopic and narrow-band surveys, the use of the deeper broadband filter coverage enables a systematic measurement of the increasingly prevalent high EWs ( > 500Å) in galaxies at every redshift spanning the 10 8 to 10 10.5 M range. Subsequently, this method was applied to all the other CANDELS fields (GOODS-South and North, COSMOS and EGS) and further corroborates these results. These results further show that EW dependence on mass is steeper for [OIII] than for Hα. Line EWs are then converted into luminosities for the three lines and fitting formulas are obtained, displaying L Hα ∼(1+z) 3.2 M 0.45−0.6log(1+z), with similar results for the other lines. L Hα is converted into star-formation rate and specific star-formation rate (sSFR). sSFR at low-z aligns approximately with the main sequence (with a steeper dependence in mass), but at high-redshift sSFR remains above the main sequence by a factor of 2 and rising towards medians SFR=100/Gyr around log(M/M )=9, showing a departure of the main sequence of star formation at lower masses log(M/M ) < 9.5. The SFRD of ELGs is 1% at low redshift, but rises to 30% at z=4.5. The L [OIII] /L Hα ratio is used to estimate L [OIII] /L Hβ and the ionization parameter q, for which the median atz > 0.5 stays approximately constant at 10 8 cm/s, and increases with mass. Using the L [OIII] /L [OII] ratio and q, median metallicity is shown to be sub-solar, and can be tentatively estimated for z > 0.5 to be Z/Z ∼0.3. The errors are large, but this could also mean a large range in metallicity from Z to 0.1Z . L [OIII] /L [OII] rises with sSFR as shown in the literature. This method shows great potential to survey emission-line-derived physical quantities for large galaxy populations with a low computational footprint, which could be particularly useful for pixel-by-pixel EW imaging. It is also flexibile, which allows it to be applied to any future deep multi-broadband fields.

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Magno, Macon, and Richard Ignace. "A Study of the H-alpha Emission Line Shape in Beta Lyrae." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/150.

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Beta Lyrae is a complex binary star system with a 13-day orbital period containing two massive stars that are in the process of mass reversal accretion. The primary star is the higher mass star which is gaining mass from the secondary star. This reversal mass accretion causes gas to build and form a disk around the primary star. The disk is geometrically and optically thick. Previous interferometric studies in Optical and Infrared wavelengths have shown that a bipolar jet exists in the system and suggest that the jet contributes to the H-alpha emission. Meanwhile, other studies have suggested that the disk contributes to the H-alpha emission. We have taken into account various factors to model the emission of H-alpha from Beta Lyrae. The observed profile is double-peaked and varies with orbital phase. We found that the jet produces a single-peak for H-alpha emission. Meanwhile, the disk produces a double-peak for H-alpha emission if it is based on Keplerian motion. We use our model to interpret the observed H-alpha emission variations in the line shape with orbital phase.

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Melnick, Ian Mark. "A diagnostic study of chlorine X-ray line emission from the compass-D tokamak." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308930.

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8

Nobukawa(Kawabata), Kumiko. "X-ray Study of Neutral Iron Line Emission in the Galactic Ridge: Contribution of Low-Energy Cosmic Rays." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215310.

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Inui, Tatsuya. "X-ray study of the variable neutral iron line emission of the Sgr B2 complex in the galactic center region." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/136867.

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10

Nelson, Keith Phillip. "An Arcminute-Resolution Imaging Study of the H-alpha & [S II] Emission of the ISM from the Local Perseus Arm Using the Virginia Tech Spectral-Line Survey." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/28638.

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The Virginia Tech Spectral-Line Survey (VTSS) is a series of 10-degree wide, arcminute-resolution images of the warm ionized interstellar medium (WIM) within the Milky Way for declinations greater than -15 degrees. The Wisconsin Hydrogen-Alpha Mapper (WHAM) studies the kinematics and distribution of this same material on an angular scale of one degree. Comparing the spatially-resolved images of the VTSS with WHAM's high spectral resolution images shows that the ISM's characteristics appear to be very similar at both degree and arcminute scales --- we see similar structures, and notice the same [S II]/H-alpha trend between those structures at both degree and arcminute scales. VTSS fields show three basic types of structures --- compact clouds with diameters greater than several degrees, those that are 1-degree or less in diameter, and extended filaments that differ from the clouds by spanning several degrees in length but having thicknesses of only a few tens of arcminutes. The latter two morphological types cannot be observed by WHAM. Additionally, VTSS data confirms that the [S II] intensity values are directly proportional to H-alpha intensities, a result that is also observed at degree resolutions. Finally, VTSS data show that [S II]/H-alpha ratios are, on average, nearly six times higher in the filaments. This would indicate that collisional excitation of singly-ionized sulfur ions is the dominant emission source within filaments. In clouds, the lower [S II]/H-alpha values observed are evidence that the H-alpha recombination line of photo-excited neutral hydrogen dominates. Because automating the VTSS was a key part of obtaining many of the images used in this project, I begin with a discussion of general observatory automation. I then address the specific processes and techniques used in automating the VTSS before discussing data collection and reduction techniques.
Ph. D.

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Mosnier, Jean-Paul. "Spectre d'émission X d'ions silicium par la méthode "faisceau-feuille"." Paris 6, 1986. http://www.theses.fr/1986PA066025.

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Analyse du spectre de rayons X émis après la traversée d'une feuille de C par un faisceau d'ions de Si de 44mev. Identification des raies satellites observées à partir de résultats théoriques par la méthode de Dirac-fock multiconfigurationnelle; mise en évidence de plusieurs configurations ayant un électron m. Par analyse des spectres à partir des valeurs calculées des rapports de branchement, confirmation d'un processus de population statistique des états excités initiaux associés à une même configuration électronique. Effet de la réponse du gaz d'électrons libres de la cible sur l'énergie de la raie de résonnance.

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Smith, Graeme Robert. "A study of helium I and II lines in the solar atmosphere." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365391.

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Sedalor, Teddy. "Heat Transfer and Flow Characteristic Study in a Low Emission Annular Combustor." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32036.

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Modern Dry Low Emissions (DLE) combustors are characterized by highly swirling and expanding flows that makes the convective heat load on the combustor liner gas side difficult to predict and estimate. A coupled experimental-numerical study of swirling flow and its effects on combustor liner heat transfer inside a DLE annular combustor model is presented. A simulated scaled up annular combustor shell was designed with a generic fuel nozzle provided by Solar Turbines to create the swirl in the flow. The experiment was simulated with a cold flow and heated walls. An infrared camera was used to obtain the temperature distribution along the liner wall. Experimentally measured pressure distributions were compared with the heat transfer results. The experiment was conducted at various Reynolds Numbers to investigate the effect on the heat transfer peak locations and pressure distributions. A CFD study was performed using Fluent and turbulence models and used to corroborate and verify the experimental results. Results show that the heat transfer enhancement in the annulus has slightly different characteristics for the concave and convex walls. Results also show a much slower drop in heat transfer coefficient enhancement with increasing Reynolds number compared to can combustors from a previous study. An introductory study of the effect of a soft wall on the heat transfer on the combustor liner is also presented.
Master of Science

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Gendre, Laura. "A study of emission of nanoparticles during physical processing of aged polymer-matrix nanocomposites." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/12381.

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Nanotechnology research and its commercial applications have experienced an exponential rise in the recent decades. Although there are a lot of studies with regards to toxicity of nanoparticles, the exposure to nanoparticles, both in terms of quality and quantity, during the life cycle of nanocomposites is very much an unknown quantity and an active area of research. Unsurprisingly, the regulations governing the use and disposal of nanomaterials during its life cycle are behind the curve. This work aims to assess the quantity of nanoparticles released along the life cycle of nanocomposites. Machining operations such as milling and drilling were chosen to simulate the manufacturing of nanocomposites parts, and impact testing to recreate the end-of-life of the materials. Several studies have tried to simulate different release scenarios, however these experiments had many variables and in general were not done in controlled environments. In this study, a reliable method was developed to assess the release of nanoparticles during machining and low velocity impact of nanocomposites. The development and validation of a new prototype used for measurement and monitoring of nanoparticles in a controlled environment is presented, as along with release experiments on different nanocomposites. Every sample tested was found to release nanoparticles irrespective of the mechanical process used or the type of material tested. Even neat polymers released nanoparticles when subjected to mechanical forces. The type of matrix was identified to play a major role on the quantity of nanoparticles release during different process. Thermoset polymers (and especially polyester) were found to release a higher number concentration of particles, mainly due to their brittle properties. A polyester sample was found to release up to 48 times more particles than a polypropylene one during drilling. The nanofiller type and percentage used to reinforce the polymer is also a key point. For example, the addition of 2 wt.% of nano-alumina into polyester increases the number concentration of particles by 106 % following an impact. The nanofiller chosen and its quantity affect the mechanical properties and machinability of the composites and therefore its nanoparticles release potential. The mechanical process and the process parameters chosen were also found to be crucial with regards to the nanoparticles released with different trends observed during drilling and impact of similar materials. Finally, thermal ageing of nanocomposites increases the number concentration of nanoparticles released (by 8 to 17 times after 6 weeks).

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Facibeni, Gabriele. "Emissioni da uso dei pesticidi negli studi di Life Cycle Assessment: calcolo dell’inventario." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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Questo lavoro di tesi si inserisce nell'ambito del progetto LIFE+ AGRICARE, il cui obiettivo è quello di dimostrare come l’applicazione di avanzate tecniche di agricoltura di precisione, abbinate a diversi tipi di coltivazione conservativa, possa avere un effetto importante in termini di riduzione di gas climalteranti e di protezione del suolo. In particolare la tesi aveva come obiettivo quello di studiare come il software PestLCI risponde quando varia la lavorazione del terreno, informazione che è inserita fra le variabili di input. Il software PestLCI calcola il frazionamento fra i diversi comparti ambientali (aria, suolo, acque sotterranee) di un pesticida sparso su un campo coltivato. Per tale motivo PestLCI può essere definito un software di supporto al calcolo dell’inventario nell’applicazione della metodologia Life Cycle Assessment. I risultati di questo studio hanno evidenziato come PestLCI vari le frazioni di pesticida emesse nei diversi comparti ambientali in base alla lavorazione del terreno. In particolare, considerando gli scenari in cui viene applicata la Terbutilazina, è stato possibile mostrare come le frazioni emesse nelle acque sotterranee siano strettamente collegate alla lavorazione del campo. Infatti queste emissioni aumentano se diminuisce la lavorazione del campo; ciò è causato principalmente dall’incremento dei macropori presenti nel suolo dato dalla minor lavorazione del terreno, i quali permettono un collegamento diretto verso le acque sotterranee e quindi facilitano le emissioni in questo comparto ambientale.

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Bortuzzo, Luca. "An X-ray study of CIV-selected AGN in the COSMOS field." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/9921/.

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Negli ultimi vent’anni innumerevoli sforzi sono stati compiuti a livello internazionale per ottenere un censimento completo degli “Active Galactic Nuclei” (AGN), ovvero di nuclei galattici attivi, oscurati in banda X. Tale censimento potrebbe rappresentare infatti la soluzione alla problematica del cosiddetto fondo cosmico non risolto in banda X. Gli studi finora condotti sfruttano la forte correlazione fra l'attività del SMBH e l'evoluzione della galassia ospite attraverso osservazioni in banda X hard, nel vicino-medio infrarosso e nell'ottico. Questa tesi si colloca in questo scenario con lo scopo di verificare e confermare l'affidabilità della selezione tramite la riga di emissione del CIV a 1549 Å di AGN oscurati fino a z≈3. Per raggiungere tale obiettivo è stato assunto che il CIV rappresenti un indicatore affidabile della luminosità intrinseca degli AGN e del loro alto potenziale di ionizzazione. Inoltre, allo studio in banda ottica delle sorgenti sono stati associati i dati profondi in banda X per analizzarne le proprietà X e caratterizzarne l’ammontare dell’oscuramento in tale banda in termini di densità di colonna di idrogeno. In particolare, in questo lavoro vengono presentati i risultati dell’analisi in banda X del campione di 192 AGN selezionati nella survey ottica zCOSMOS-Deep, attraverso la riga di emissione del CIV a 1549 Å. Queste 192 sorgenti hanno un redshift medio di 2.2 e una magnitudine media AB in banda B di 23.7. La copertura in banda X del campo selezionato è data dalla survey Chandra COSMOS-Legacy comprendente 4.6 Ms di osservazioni in un’area di 2.2 deg2. I risultati ottenuti in questo progetto di tesi tramite la selezione possono ritenersi soddisfacenti: metà delle AGN di Tipo 2 selezionate con il CIV e rilevate in banda X risultano fortemente oscurate (NH>10^23 cm^(-2) ). Inoltre, le AGN di Tipo 2 non rilevate in banda X risultano consistenti con uno scenario di oggetti oscurati.

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Di, Carlo Alessia. "Building emissions in the pre-use phase: the case study of a multi-story residential building in Tampere Emissioni di edifici nella fase pre-uso: il caso studio di un edificio residenziale multipiano a Tampere." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23838/.

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A causa del largo utilizzo di acciaio e calcestruzzo per la costruzione degli edifici, il settore delle costruzioni è responsabile di un terzo delle emissioni globali di gas serra in atmosfera. Il presente lavoro di tesi mira a valutare le emissioni di anidride carbonica dovute alla costruzione di un edificio con materiali convenzionali e a confrontarle con le emissioni dello stesso edificio se fosse in legno laminato: in particolare vengono analizzati tre principali scenari: nel primo si analizza l’edificio costruito con materiali convenzionali, nel secondo vengono sostituiti da materiali convenzionali sostenibili, nel terzo viene eliminato il calcestruzzo e al suo posto vengono inseriti pannelli di legno laminato. Viene utilizzato il software One Click LCA prodotto dalla Bionova, che, valutando le fasi di estrazioni di materie prime, lavorazione, produzione, trasporto e messa in opera, permette di quantificare l’anidride carbonica immessa in atmosfera in seguito a tali processi. Dai risultati emerge un netto miglioramento sin dal secondo scenario in cui le emissioni si riducono del 47%, al terzo scenario dove si abbassano del 75% rispetto al valore iniziale: per questo motivo, un’analisi LCA dovrebbe essere sempre effettuata durante la progettazione di un edificio.

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Sharma, Sabita. "Life Cycle Assessment of Municipal Solid Waste Management regarding Green House Gas Emission: A Case Study of Östersund Municipality, Sweden." Thesis, Mittuniversitetet, Institutionen för teknik och hållbar utveckling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-17409.

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This study aims to undertake a comprehensive analysis of different waste management systems for the wastes produced in Östersund municipality of Sweden with an impact assessment limited to greenhouse gas emissions and their total environmental effects in terms of global warming potential, acidification potential, and eutrophication potential. A life cycle assessment methodology is used by integrating knowledge from waste collection, transportation, waste management processes and the product utilization. The analytical framework included the definition of functional unit, system boundaries, complimentary system design, waste management, and partial use of the energy. Three different municipal solid waste management scenarios, incineration, composting, and digestion were considered for the study. All wastes from Östersund municipality were classified into biodegradable and combustible and thereafter treated for energy and compost production. Greenhouse gas emissions and total environmental impacts were quantified and evaluated their corresponding benefits compared to three different types of marginal energy production system. The results showed that the major greenhouse gas carbon dioxide and nitrous oxide emissions are greater in composting scenario, whereas methane emission is greater in digestion scenario. Composting scenario that uses additional coal fuel has greater global warming potential and acidification potential compared to other scenarios. Composting scenario using wood fuel additional energy has greater eutrophication potential. The highest reduction in global warming potential is achieved when digestion scenario replace coal energy. The greater reduction in acidification and eutrophication potential achieved when digestion scenario replaced coal energy, and wood fuel respectively. Based on the assumptions made, digestion scenario appears to be the best option to manage solid waste of Östersund municipality if the municipality goal is to reduce total environmental impact. Although there may have plentiful of uncertainties, digestion and incineration scenario results are competitive in reducing environmental effects, and based on the assumptions and factors used for the analysis, the results and conclusions from this study appear to be strong. Key words: Solid waste, incineration, composting, digestion, total environmental effect, wood fuel, biogas.

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Sarda, Estève Roland. "Étude de la variabilité des bioaérosols atmosphériques en région île de France." Electronic Thesis or Diss., université Paris-Saclay, 2021. http://www.theses.fr/2021UPASJ004.

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Les bioaérosols atmosphériques sont des particules d’aérosols biologiques primaires en suspension dans l’air et référencés dans la littérature comme étant des: Primary Biological Aerosol Particles (PBAPs). Les PBAPs sont de tailles et de natures très différentes. Ils ont la capacité à agir comme noyaux de condensation nuageux ou de glace et participent ainsi au cycle de l’eau sur terre. Ils peuvent être transportés loin de leur zone d’émission et coloniser de nouveaux écosystèmes. Leur caractère allergisant ou pathogène a un impact sur la santé humaine et animale. Ce travail de thèse qui porte sur l’étude de la variabilité des bioaérosols atmosphériques en région île de France concerne les pollens, les moisissures et les bactéries. Les observations ont été réalisées dans la couche limite à l’observatoire du SIRTA/LSCE. Ce travail pionnier dans la région Francilienne a permis: (1) de documenter la variabilité interannuelle, saisonnière et journalière propre à chacun des PBAPs, (2) de déterminer leurs origines géographiques respective, (3) d’étudier les paramètres météorologiques qui gouvernent leur cycle de vie dans l’atmosphère. Mon dernier objectif (4) a été de developper un instrument de mesure en temps reel des PBAPs et plus specifiquement des pollens
Atmospheric bioaerosols are particles of primary biological aerosols suspended in the air and referred in the literature as: Primary Biological Aerosol Particles (PBAPs). PBAPs have very different sizes and coposition. They have the ability to act as cloud condensation nuclei or ice nuclei and thus participate in the water cycle on earth. They can be transported far from their sources and they can in this way colonize new ecosystems. Their allergenic or pathogenic propoeries have an impact on human and animal health. This work on the variability of atmospheric bioaerosols in the Ile de France region concerns pollens, molds and bacteria. The observations were made in the boundary layer at the SIRTA/LSCE observatory. This pioneering work in the Ile-de-France region had the objective to: (1) document the interannual, seasonal and daily variability specific to each of the PBAPs, (2) determine their respective geographical origins, (3) study the meteorological parameters that control their life cycle in the atmosphere. My last objective (4) has been to develop an on line instrumenst to measure in real time BPAPs concentrations with a focus on pollen

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Maroly, Anupam. "The development of a sensitive method to study volatile organic compounds in gaseous emissions of lung cancer cell lines." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2423.

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The ultimate objective of this research was to develop a low cost, reliable system that would lead to early detection of lung cancer. Tests involved the quantitation of gaseous metabolic emissions from immortalized lung cancer cell lines in order to correlate the chemical markers to be of cancerous origin. The specific aims of the project were the study of gas emissions in selected cancer cell lines and identification of volatile organic compounds (VOCs) in them. Disadvantages of earlier studies were that the measurements were not real time or state specific so that molecular identification was often inconclusive. Furthermore the methods of study used in the past were not quantitative, which limited their practicality for medical applications. We felt the need to prove or disprove these earlier results using a new technique. The method we proposed is different and unique when compared to previous methods because cell lines have not been studied extensively for cancer markers. We have studied cancer cell lines which are adherent, immortalized cultures originating from primary tumors obtained from patients with no prior treatment for lung cancer. We have used an alternative method for the spectrometric analysis and quantitation of the selected chemical markers. The pre-concentration method involved a Purge and Trap unit with a thermal desorber where the vapor concentration was enhanced. The concentrated head space gases were analyzed using a Gas Chromatograph ?? Mass Spectrometer setup. This setup eliminated the bulky apparatus used in earlier studies. It is simpler in design and more comprehensive so that external factors such as patient??s diet, habitat and lifestyle do not contribute to our study of recognition of cancer markers. Based on the results obtained in the above experiments, a more comprehensive, inexpensive study of lung cancer related markers could be made. The first section, after giving an introduction to lung cancer, goes on to explain the background work done by other researchers on cancer. The third section gives a detailed explanation of the experimental setup. This is followed by all the tests conducted with corresponding results. The final section deals with the conclusions drawn from all experiments.

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Nord, Iza. "Reducing Greenhouse Gas Emissions Through the Use of Free Shops : A Case Study of Two Free Shops in Gothenburg." Thesis, Mittuniversitetet, Avdelningen för ekoteknik och hållbart byggande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-33920.

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Products, throughout their life cycle from production to waste management, create emissions of greenhouse gases (GHG). This leads to environmental impacts on the climate (Swedish Environmental Protection Agency, 2016). The consumed products from households are increasing (World Wildlife Fund, 2008) and so is the waste generated from them (Avfall Sverige, n.d.). A more sustainable development generating from circular economy should be focused on to increases the reuse of products and by so reduce the amount of waste generated (Göteborgs Stad, n.d.a.) This study have examined if the use of Free Shops can help the city of Gothenburg to reach higher up the waste management hierarchy towards reuse and prevention, and if carbon dioxide equivalents (CO2e) can be avoided by using Free Shops. Two Free Shops with the purpose to increase reuse in Gothenburg have been studied and their effect on GHG emissions, presented as CO2e, have been analysed. A Life Cycle Inventory Study (LCI) has been conducted on all, but two, different materials entering the Free Shops for four weeks, including the production, waste management, transportation and storage. The result of the study shows that a mean of 10 ton CO2e per Free Shop per year can be avoided when reusing at a Free Shop instead of buying new products. This equals leaving a low energy lamp on for approximately 590 years (World Wildlife Fund, 2009) based on a low energy lamp using 0,007 kWh (Eon, 2007). To examine if the Free Shops can reduce the amount of waste disposed of by households in Gothenburg the material entering the Free Shops was weight and analysed to estimate how it corresponded to the amount of waste disposed of. The result shows that the material entering a Free Shop only corresponds to 0.0025 percent of the household waste disposed of in the city. This indicates that Free Shops by themselves will not solve the problem with increasing amounts of waste and emissions from increasing production. However, they can help in a small scale.

20180625

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22

Zhao, Huawei. "Computational models and numerical techniques for solving Maxwell's equations : a study of the heating of lossy dielectric materials inside arbitary shaped cavities." Thesis, Queensland University of Technology, 1997.

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Stempels, Henricus Cornelis. "An Observational Study of Accretion Processes in T Tauri Stars." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3420.

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Yuning, Jiang. "LCA of Microgrid System: a Case Study at ‘North-five Islands’ of Changshan Archipelago, China." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264264.

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Microgrid can provide stable, clean, and sustainable electricity supply for remote places since it can operate on renewable energy sources and work isolated from the utility grid. This thesis evaluates the life cycle greenhouse gas (GHG) emissions of the microgrid system which is located at the ‘North-five Islands’ of Changshan archipelago in China. The existing electricity generation technologies of the microgrid system are wind turbine, PV system and diesel generators with the capacity of 2 MW, 300 kW and 2046 kW, respectively. The total demand of electricity (362.2 GWh) will be supplied by the wind turbine, PV system and diesel generators with 32.03%, 2.36% and 65.62%, respectively, if the microgrid system is required to supply the electricity demand for the ‘North-five Islands’ area alone under the islanded mode during 20 years lifespan. The thesis uses the Life Cycle Assessment (LCA) to evaluate the life cycle GHG emissions of the microgrid system. The life cycle stages of this study include: raw material extraction, manufacturing, transportation and operation. In order to assess the environmental benefits of the microgrid system, three electricity supply options – ‘microgrid electricity supply option’, ‘grid extension electricity supply option’, and ‘conventional fossil diesel generators electricity supply option’ are designed to evaluate the life cycle GHG emissions for supplying 20 years electricity demand (362.2 GWh) of the ‘Northfive Islands’. The results show that the life cycle GHG emissions of the ‘microgrid electricity supply option’ are 223.19 million kgCO2eq. Compared to the ‘grid extension electricity supply option’ and ‘conventional fossil diesel generators electricity supply option’, the net savings of the GHG emissions are 70.56 and 112.18 million kgCO2eq, respectively. It mainly results from the differences of the electricity supply methods of the three electricity supply options. For the ‘microgrid electricity supply option’ itself, the operation stage takes the most responsibility of the life cycle GHG emissions with 97.6%. The raw material extraction, manufacturing and transportation stages account for 1.93%, 0.44% and 0.026%, respectively. For the system components of the microgrid system, the wind turbine, PV system, diesel generators, energy storage system, and cables account for 0.34%, 0.18%, 97.75%, 0.60%, and 1.12%, respectively, of the microgrid system’s life cycle GHG emissions. The thesis conducts the sensitivity analysis of diesel burn rate efficiency (L/kWh) of the microgrid system’s diesel generators due to a large quantity (60.84 million L) of diesel consumption by the diesel generators during 20 years operation time. According to the results of the sensitivity analysis, the diesel burn rate efficiency can directly impact the diesel consumption of the diesel generators, and consequently has a significant impact on the life cycle GHG emissions of the ‘North-five Islands’ microgrid system. Since the diesel burn rate efficiency represents the amount of diesel consumption, this results highlight the significance of any factors that affect the diesel consumption (e.g. quantity of diesel, temperature, altitude, etc.), in affecting the life cycle GHG emissions of the ‘North-five Islands’ microgrid system. In addition, the thesis performers the sensitivity analysis of renewable energy (wind and solar energy in specific) fraction of the studied microgrid system because of the huge potential of available renewable energy (63.65 MW of wind turbines) nearby the microgrid system. The results of the sensitivity analysis show that the life cycle GHG emissions of the microgrid system decrease linearly with the increase of wind and solar energy fraction. Particularly, the life cycle GHG emissions of the microgrid system decrease 1.46% (3.26 million kgCO2eq) and 1.37% (3.05 million kgCO2eq) with an increase of 1% in wind and solar energy, respectively.

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Moran, Madeline Elyse. "An environmental and cost comparison between polypropylene plastic drinking straws and a "greener" alternative: An Oberlin case study." Oberlin College Honors Theses / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1526393902586631.

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Chung, Ming-Hsien, and 鍾明憲. "Positron Emission Tomography-based study in Hepatocellular carcinoma: 18F-FDG and 11C-MET uptake in HCC cell line." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/78026005703905063226.

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碩士
國防醫學院
生物及解剖學研究所
99
Hepatocellular carcinoma (primary liver malignancy or called hepatoma) is the most common type of liver cancer. In Taiwan, the incidence of hepatoma has been estimated to be 27.7 of 100,000 peoples every year. It ranks the first and second cancer-related death in male and female, respectively. The clinical assessment tools for patients with hepatoma include serum alpha-fetoprotein (AFP) check up and several modalities of imaging study. The latter ones consist of sonography, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). Among which, PET is useful to survey tumor metabolism by using different tracers. In clinical practice 18F-Fluoro-deoxyglucose (FDG) is the most commonly used oncological PET tracer. Most cancer cells can accumulate FDG via membrane glucose transporter and phosphorylation of FDG by enriched hexokinase expression, thus allowing the FDG-avid tumor cells to be detected by PET. However FDG is not a completely satisfied tracer for hepatomas because of the various expression of glucose-6-dephosphatase (G6PD) inherent to hepatocytes, which may evacuate the tracer from tumor cells once FDG is de-phosphorylated by G6PD. The G6PD activity varies in hepatomas with different differentiation and therefore affects the detection rate of FDG PET. Alternative PET tracers such as 11C-acetate and 11C-choline have been proposed and their use to detect certain non-FDG-avid hepatomas has been reported preliminarily. Our previous study has demonstrated the use of 11C-methionine (Met) to localize hepatomas. Briefly we found that the primary hepatomas showed Met-void while extra-hepatic hepatomas presented as Met-avid lesions. Conversely the intra-hepatic Met-void lesion showed FDG avidity. To further explore the related mechanism, the study of in vitro Met uptake in hepatomas was performed using three different cell lines (HepG2, Hep3B, HA59T). Also two known differentiation modifiers including All-trans retinoic acid (ATRA) and Trichostatin A (TSA) were adopted to intervene the hepatomas. Met and FDG uptake in ATRA- or TSA-treated hepatomas were compared and correlated with the pertinent tumor growth. The result showed that all these three cell-lines shared the response of growth arrest as well as increased apoptotic potential with either ATRA or TSA treated hepatoma cells in vitro. Their FDG uptake was significantly lowered and Met uptake was enhanced in presence of TSA. The change followed a dose-depend manner. With ATRA treatment, dose-dependent increased Met uptake was also demonstrated in hepatomas. However there was similar change of FDG uptake in ATRA-treated hepatomas. In conclusion Met uptake in hepatomas can be regulated by ATRA or TSA treatment and whether it is related to the effects of differentiation or anti-tumor activity known for ATRA or TSA remains uncertain. The role of Met uptake as a biomarker for hepatoma therapeutics related research warrants for further study.

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Hsiang, Chih-Fan, and 范智翔. "Study of Microcrystalline Silicon Thin Film Deposition by 40.68 MHz In-Line PECVD and Plasma Emission Spectroscopy Analysis." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/32511263171754467003.

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碩士
國立清華大學
工程與系統科學系
101
Abstract Thin-film solar cells are fabricated by low-cost production processes, and deposited on low-cost substrate like glass, stainless steel or plastics. Therefore, thin-film solar cells are an alternative to conventionally used wafer solar cells based on crystalline silicon. The hydrogenated microcrystalline silicon(c-Si:H) thin film solar cells have better absorption efficiency at near infrared and better resistance to degradation caused by sunlight illumination. The purpose of this thesis is develop process for c-Si:H thin films by In-line plasma enhanced chemical vapor deposition(In-line PECVD). When in the process, optical emission spectroscopy(OES) be employed to monitor the stability of plasma and to build the relationship between plasma spectrum and process parameters such as RF power, gas pressure and silane concentration. Correlation among plasma reactive species, process parameters and thin film are established by analyzing material property of thin film and electric property. In addition to SiH* (412.8 nm), the H (656.2 nm), the H (486.2 nm) and the H2 Fulcher (600-630 nm), we also interest in Si* (288 nm) and use OES-ratio(Si*/SiH*, H/Si*H/Si*) to analyze connection between electron temperature and process parameter. We also compared new OES-ratio(Si*/SiH*, H/Si*H/Si*) with OES-ratio(H/H to understand the reaction mechanism of plasma further. H2 fulcher is used to represent the trend of electron density. c-Si:H thin films are prepared by the silane-hydrogen plasma with VHF-PECVD (40.68 MHz). The experiment results found that whether it is varying the silane concentration, RF power or gas pressure, the XC and OES-ratio(H/SiH*, H/SiH*) have the same trend, but the trend of photosensitivity is opposite except for RF power. In the part of electron temperature, OES-ratio(HH, Si*/SiH*) increase with RF power. They also increase with pressure but that are not consistent with the simulation results. But when we replaced OES-ratio(HH, Si*/SiH*) with OES-ratio(H/Si*, H/Si*), the trends of OES-ratio(H/Si*, H/Si*) are consistent with simulation result. The intensity of plasma characteristic species and electron density have the same trend. When the RF power increases, the emission intensity of plasma species get higher as a result of the increases of electron density. But when the gas pressure increases, the intensity of plasma species get lower as a result of the decreases of electron density.. For the different silane concentration, electron density has irregular trend when the silane concentration increase. In the part of electron temperature, there is opposite trend between OES-ratio(HH) and OES-ratio(Si*/SiH*). The trend of OES-ratio(H/Si*) and OES-ratio(H/Si*) are also different depend on variation of silane concentration. Among of them, OES-ratio(H/Si*) has irregular trend, too. Currently, In-line PECVD can deposit c-Si:H thin film which XC = 42% and photosensitivity = 8.74 × 102 at high power(1000 W), high pressure(5 torr) and high silane concentration(3.3%). But the cell efficiency is just 0.01%. Therefore we use lower RF power to reduce the defect at junction between Barrier-layer and I-layer by reduced ion bombardment. When the RF power lower to 600 W, gas pressure at 4 torr, the cell efficiency has been improved dramatically to 4.05%. If the N-I-P layer all deposited in In-line PECVD, we expect the cell efficiency will be improved more.

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Voisin, Fabien. "Environment Studies of Pulsar Wind Nebulae and Their Interactions with the Interstellar Medium." Thesis, 2017. http://hdl.handle.net/2440/119266.

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Pulsars, rapidly rotating neutron star born from the core-collapse of massive stars, convert a fraction of their rotational energy to accelerate electrons up to high energies. The generated pulsar wind eventually reaches the termination shock and creates a pulsar wind nebula (PWN). There, the particles’ trajectories become randomized, and they produce radio to X-ray emission via synchrotron radiation; and TeV γ-ray emission from the interaction of high energy electrons with the Cosmic Microwave Background; and the infra-red emission from Galactic dust. Although progress has been made towards the understanding of the structure of the pulsar environment, several issues, such as the composition of the pulsar winds, still need to be addressed. Indeed, no direct evidence of hadronic components have yet been discovered inside the PWN. However, nearby dense molecular clouds could provide sufficient target particles for the potential hadrons from the PWN and its progenitor supernova remnant (SNR) to produce significant TeV emission via proton-proton (p-p) interaction. My work thus first consists of conducting interstellar matter (ISM) studies towards several PWNe using the 22-metre Mopra and the 4-metre Nanten radio telescopes. Among the studied PWNe, I particularly focus on HESS J1825−137 and its plausible association with the nearby unidentified TeV source HESS J1826−130. I have mapped the HESS J1826−130 region with Mopra in the 7 and 12 mm bands which, combined with the Nanten CO(1–0) survey and the GRS ¹³CO(1–0), enable an accurate analysis of the morphological and physical properties of several dense molecular clouds found in the line of sight. Interestingly, I have found a massive molecular cloud adjacent to the PWN HESS J1825−137 and overlapping the HESS J1826−130 TeV emission. From our mass estimates, I suggest that the cosmic-rays originating from the progenitor SNR of the pulsar PSRJ1826−1334 can significantly contribute to the TeV emission. We then attempt to model and predict spectral and morphological properties of the TeV emission from the propagation of high energy CRs and electrons, originating from the progenitor SNR and potentially from the PWN.We find that the resulting spectral shape of the TeV γ-ray emission is very sensitive to the diffusion coefficient of high energy particles inside molecular clouds. I also find that only a ‘slow’ diffusion’ of CRs (diffusion coefficient D(E) ∼ 10²⁶ √E/10GeV cm² s⁻¹) results in a significant contribution of the gamma-ray emission towards HESS J1826−130 at all energies. We finally notice that the contribution from hypothetical CRs escaping the PWN HESS J1825−137 is expected to be overshadowed by the contribution of CRs escaping the progenitor SNR. As one expects the latter’s contribution to decrease as time evolves while the former’s contribution to remain somewhat constant, I thus argue that older PWNe may be more suitable candidates to obtain direct evidence of CRs inside PWNe. Among the studied PWNe, I find that, based on simplistic diffusion studies, the ISM surrounding HESS J1809−193 may be a good laboratory to detect CRs escaping the pulsar PSRJ1809−1917.
Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 2017

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Chuang, Feng-Yu, and 莊鋒域. "Study on Electron Field Emission Characteristics of Diamond-like Carbon Films." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/59845223994449579281.

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博士
國立台灣工業技術學院
電子工程技術研究所
84
In this thesis, pulsed laser deposition process was used to synthesized the diamond like carbon (DLC) films on silicon substrate, with different intermediate layer. The effects of crystal structure and morphology of the films on electron field emission characteristics were analyzed, in order to understand the electron field emission mechanism. The application of these films to electron emission devices, i.e., triode and diode emitters, are also characteristized. Raman spectra show that the DLC films deposited at 60~200℃ possess G- bandresonance peak occurred at around 1550 cm-1, inferring high sp3/sp2 ratio (~80%) of these films, whereas transmission electron microscopy indicates that the existence of nanocrystalline diamonds. By contrast, the DLC films grown at 400-600 degree were predominated with sp2-bond, i.e., G-band resonance peak occurred at around 1600 cm-1. The sp3/sp2 ratio is lower than 20 %. The DLC films deposited at low temperature, which have high sp3/sp2 ratio, possess lower turn-on electric field and imply that electron field emission arises from nanocrystalline sp3-phase. Atomic force microscopy (AFM) analyses indicate that the DLC films contain clusters of the size of 20~50 nm. The surface roughness is around 20 nm for the films deposited at higher temperature. The effective work functions estimated from the Fowler-Nordheim plot of I-V curve, measured by diode method, are around 0.02-0.04 eV, whereas those estimated from the I-V curve measured by STM are around 0.7-1.16 eV. These results imply that surface morphology of the DLC films markedly affected the electrical field concentration effect and, thereafter, pronouncedly modified the effective work function of the emission sites. Local field emission behavior measured by STM technique using 50 nm W-tip indicates that emission current density varied as the probe scanning across the clusters. A large emission current density as 760 A/ cm2 can be achieved under E=400 V/um applied field, which corresponding to 110 nA under 4.0 V with 5 nm tip-to-film distance. On the other hand, the intermediate layers were observed to significantly modify the films field emission characteristics. Among the intermediate layer studied, i.e., Mo, Cr, Pt and Au metallic layers, the Au-layer is most satisfactory. Pre-annealing is, however,necessary. The field emission can be lowered to 7 V/um, whereas the emission current density can reach 2 mA/cm2 at 20 V/um applied field. SIMS and SEM analyses indicated that interdiffusion between DLC and Au layers has occurred, which facilitates the electron transportation from substrate accrossing the interface to emission sites, the electron field emission properties. The average electron emission current density measured by diode method reached 2 mA/cm2 at 20 V/um. The local emission current density measured by STM method achieved a high value as 4400A/ cm2 at 100 V/um. The excellent emission current density was reached 3200 mA/cm2 and 140 mA/cm2 for triode and diode structure, respectively. The above results imply that the sp3-clusters are the emission sites and the sp2-clusters behaves as the electron transport path in the DLC films. Good conductivity at films-to-substrate interface, in DLC films (i. e., sp2- clusters) and inside the DLC clusters(i.e.,B-doping) facilitated the electron transport from substrate to emission sites. The field emission current density can thus be markedly enhanced at substantially lower the turn-on field.

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Shaiw, Chen Wei, and 陳維孝. "Study on Electron Field Emission Characteristics of Diamond-like Carbon Films." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/23666335998307808648.

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碩士
國立臺灣科技大學
電子工程學系
84
Diamond like carbon (DLC) films possessing excellent electron emission characteristics was obtained by pulsed laser deposition (PLD) technique. Either 193 nm (ArF) or 248 nm (KrF) laser beams was used to synthesize the DLC films under various conditions in this research. The deposition parameters: substrate temperature ,laser wavelength, laser energy density and ambient pressure were investigated to recognize the relationship between DLC-films and electron field emission characteristics. Raman spectra and atomic microscopy (AFM) were utilized to examine the structure and morphology of these films. The electron field emission properties were characterized using diode-method measurement. The diamond like carbon films were characterized among various deposition condition. For the films deposited at 200 ℃(ArF, 4J/Square centimeter) or 400 ℃(KrF,10J/Square centimeter), Raman spectrainferred that the G-Band located at 1550 cm-1, i.e. , sp3 and sp2hybrid bonding. The thickness of the films was about 3000and the cluster size around 5-20nm. Current-voltage (I-V) measurement using a diode method, however, indicated that theturn on electric field can be as low as 10 MV/meter and the emission current density was as large as 132 mA/Square centimeter under 20MV/meter .

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ZHANG, SHENG-HONG, and 張盛鴻. "A study about acoustic emission in drill-life predicting and abnormal drilling detecting." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/85894853622168289799.

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32

Tseng, Chien-tai, and 曾建臺. "Study on Electron Field Emission Characteristics of Boron-Doped Diamond-Like Carbon Films." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/72368621157670037205.

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碩士
國立台灣工業技術學院
電子工程技術研究所
85
In this thesis,the electron emission properties and stability of amorphousdiamond like carbon(DLC) films were examined by using pulse laser deposition(PLD) technique. The effects of intermediate layer and boron doping on electron field emission were also characterized. The current-voltage measurements indicated that a large emission current density as 1.4mA/cm2 turn-on electrical field 6.7 V/um for B-DLC/Au/Si was superior to 440 uA/cm2(turn-on electrical field 11.6 V/um) for DLC/Au/Si. Similar results were alsoshowed in B-DLC/Cr/Si and DLC/Cr/Si. The high stability in the emission properties had been confirmed under long time I-V testing (DC mode, 720 min.).The short-term fluctuations obtained are 5%. The above results imply that the intermediate layers and boron-doping wereobserved to significantly modify the emission behaviors. Among the intermediate layer studied, i.e., Mo, Cr and Au metallic layers, the Au-layeris most satisfactory. SIMS analysis indicated that interdiffusion betweenDLC and Au layers has occurred, which facilitates the electron transportaionfrom substrate acrossing the interface to emission sites. The interdiffusiondecreased the barrier height in the interface. Boron-species were also occurred in the intrinsic DLC films by using SIMS analysis. The incorporation of boroninduces more electron conduction path and thus induced large electron emission.The effects of deposition parameters,interface and boron-doping on electronfield emission will be discussed in detail in this study.

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33

Shen, Cheng-Yeng, and 沈政彥. "The Study of Diamond-like Carbon Films for the Application of Field Emission Display." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/71153713235604734715.

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34

Chiang, Dien-Shen, and 江典聲. "A Study on the filed emission of diamond-like carbon films on glass substrates." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/88825641021683926257.

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35

Zeng, Yi-cheng, and 曾頤誠. "Study on reduction potential of CO2 emission from daily life water saving in Taiwan." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/40702323783032807895.

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碩士
國立臺灣科技大學
建築系
101
Since the global warming becomes more serious in recent years, the countries have put forward strategies facilitating the reduction of CO2 emission. However, most of the strategies focus on the conservation of power consumption, energy and resources currently in Taiwan, with numbers of relative literatures and outcomes; but few study on the reduction of water consumption. Common families are seldom aware that water conversation can also reduce the CO2 emission efficiently, because the energy consumption of residential water is relatively smaller than that of air-conditioning system and is added up into the power consumption, which is not so easy to perceive its amount and importance. That is to say, the energy consumption in using water may be easily neglected in energy conversation measures in building. For this reason, this research tries to get rid of the general ideas about daily energy and power conversation, to explore the energy consumption in using water. According to the research results, 0.492 kg carbon will be discharged when using 1.0 m3 of water in daily life generally and 6.52 kg in case of 1.0 m3 of hot water. Based on the reconfirmation of energy consumption when using 1m3 of water and hot water respectively, it works out the prediction equation for carbon emission in using different types of water. From the research, it is learned that the annual average carbon emission per capita in total water used is 224 kg, accounting for 2.06% of the total annual carbon emission of 10.9 metric tons in Taiwan. To efficiently reduce the annual carbon emission in using water, this study proposes four water conservation strategies, which are estimated to reduce 153 kg carbon emission, from 2.06% to 0.6%. The carbon emission of residential water has a potential to be reduced by 11.4%, which contributes a total reduction of 1.5% in national total emission , proofing the reduction potential of CO2 emission. Finally, it is hoped that this research can reach the carbon emission standards made by the government in 2000 or even the baseline by Kyoto Protocol in 1990. Moreover, it may realize the standard of a water-saving society in which each person saves 150 m3 in terms of residential water every day, and even reach the level of 100 m3 before 2020 with the evolutions of technologies and equipments.

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Kuo, Shin-heng, and 郭信亨. "Study of Growth and Property on Field Emission Diamond-Like Carbon Film by MPECVD." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/yjvt86.

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碩士
國立臺北科技大學
材料科學與工程研究所
95
Diamond-like carbon film exhibits excellent properties which had a lot of corresponding application at the industry, especially, Diamond-like carbon film present the potentiality of development on the application of the field emission devices within thermal stability , low work function and negative electron affinity. In this study, a dual-ellipsoid type Microwave plasma enhanced chemical vapor deposition equipment for diamond-like carbon film deposition has been developed. The system pressure, H2CH4 flow rate, deposition temperature and microwave power were changed to investigated the microstructure、banding conformation and Field Emission properties of Diamond-like carbon film.Also, we observed the surface and cross section structure, analysis banding conformation and discuss Field Emission properties of Diamond-like carbon film by using Scanning Electron Microscope 、Raman Spectrometer and Electronics Measurement System. We find that the diamond-like carbon ( DLC ) near and outside the plasma can be deposited without heating . The turn-on voltage ( Vth ) decreased and current density increased with lowered the microwave power and H2 / CH4 flow rate. The parameters with microwave power, 400W, and the H2CH4 flow rate, 1:10, will optimize the turnon voltage and current density to 5.5V/μm and 300μm/cm2, respectively.

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37

李東哲. "Study on field emission characteristics of flake-like nanocrystalline graphite films fabricated by CVD method." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/91908151436754604991.

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碩士
國立清華大學
動力機械工程學系
101
In our research, flake-like nanocrystalline graphite(NCG) films were grown on the silicon substrate using hot-filament chemical vapor deposition(HFCVD) system. We observed NCG’s surface morphology, uniformity, crystal quality and measured their field emission properties after changing process parameters like gas ratio, growth temperature, adding nitrogen and using pretreatment. Afterward we fabricated the Ultra-nano crystalline diamond(UNCD) and NCG composite films and discussed their properties. Finally, we fabricated NCG, UNCD and UNCD/NCG pyramid-type field emission arrays by using lithography technique, anisotropic etching technique and molding technique. The experimental showed that the turn-on field on the NCG film grown by using 9% methane concentration was 12 V/μm. After adding nitrogen, the turn-on field decreased to about 6~8 V/μm. The turn-on field on the UNCD/NCG composite films were about6~7 V/μm. We observed the reproducibility on UNCD/NCG composite films’ field emission behavior due to the high thermal conductivity and mechanical strength on UNCD. For improving the field emission facter, we fabricated the pyramid-type field emission arrays. They were 8.4 μm in height, 12 μm in base length and 3 in the pitch to base length ratio . The lowest turn-on field of 4.78 V/μm can be obtained in NCG pyramid-type field emission arrays.

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Lai, Cheng-Wei, and 賴晟偉. "A study of life-cycle CO2 emission of residential building - case study of the reinforced concrete construction comparison with steel structure." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/y3vs65.

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碩士
國立臺北科技大學
建築與都市設計研究所
98
In this study, the building life-cycle assessment <Life Cycle Assessment ,LCA> the overall concept of the building plans to explore the building construction materials and the establishment of Taiwan''s carbon dioxide emissions, as a global ecological and green building environmental impact assessment indicators section. First, the present building to create the materials needed to calculate the amount of material made according to the calculation of CO2 emissions, and calculate the sum of total CO2 emissions from buildings, followed by the actual case for this analysis and discussion, to make concrete conclusions and recommendations. In this research, done in two different tectonic analog operation objects, in the same building height and the same total floor area of the structure in two different ways under the conditions of CO2 emissions, the data, drawn steel construction and reinforced concrete construction the overall emissions of carbon dioxide the amount of load on the environment, this study concludes with construction materials expected CO2 reduction countermeasures, in the production of low-power, high recycling, waste re-use of building materials, to reduce the load of the built environment objectives.

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Laio, Chun-Hao, and 廖俊豪. "The life cycle assessment of carbon emission and sequestration during the urbanization process: a case study of Linkou Designated Area." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/81928735108985937453.

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碩士
中國文化大學
景觀學系
99
The global warming phenomenon is getting more and more serious each day. To prevent the global environment from constantly getting worse, the IPCC (Intergovernmental Panel on Climate Change) has come up with a world climate change response structure based on mitigation and adaption. So far, the studies on climate change and the decrease of carbon dioxide were mostly concentrated on subjects such as, transportation, industrial department, energy technologies, and fuel economic policies, but we rarely discuss the carbon dioxide’s release and absorbsion that are produced from transportation needs and energy expense during the urbanization progress. Therefore, in this article, we are going to discuss the changing environment and greenhouse gas’ release and absorb under the changing landscape usage from the urbanization policies. Using Taipei county Linco area as an urbanization case study, we will combine the 1971, 1995, and 2007’s landscape usage statistics and use methods, like life cycle assessment and GIS (Geographical Information System) , to estimate the difference between he carbon dioxide’s release and absorb before and after the announcement of the area’s urbanization plan. From what we know, not only can we fully understand the changing of the whole process by using the Life Cycle Assessment, we can also show the difference in the carbon dioxide’s absorb and release under all kinds of city policy scenarios through the results of the study data. In this study, we discovered that the urbanization progress which was driven by area’s planning has caused the condition of the carbon dioxide’s absorb and release in the Linco area to change dramatically; we also find out in the analysis of policy scenarios, if we can combine all kinds of greenhouse gas decreasing policies and lower emission standards, we will be able to lower the impact of carbon releasing.

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40

(9746375), Timothy Simon. "A Study of Additive manufacturing Consumption, Emission, and Overall Impact With a Focus on Fused Deposition Modeling." Thesis, 2021.

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Additive manufacturing (AM) can be an advantageous substitute to various traditional manufacturing techniques. Due to the ability to rapidly create products, AM has been traditionally used to prototype more efficiently. As the industry has progressed, however, use cases have gone beyond prototyping into production of complex parts with unique geometries. Amongst the most popular of AM processes is fused deposition modeling (FDM). FDM fabricates products through an extrusion technique where plastic filament is heated to the glass transition temperature and extruded layer by layer onto a build platform to construct the desired part. The purpose of this research is to elaborate on the potential of this technology, while considering environmental impact as it becomes more widespread throughout industry, research, and academia.

Although AM consumes resources more conservatively than traditional methodologies, it is not free from having environmental impacts. Several studies have shown that additive manufacturing can affect human and environmental health by emitting particles of a dynamic size range into the surrounding environment during a print. To begin this study, chapters investigate emission profiles and characterization of emissions from FDM 3D printers with the intention of developing a better understanding of the impact from such devices. Background work is done to confirm the occurrence of particle emission from FDM using acrylonitrile butadiene styrene (ABS) plastic filament. An aluminum bodied 3D printer is enclosed in a chamber and placed in a Class 1 cleanroom where measurements are conducted using high temporal resolution electrical low-pressure impactor (ELPI), scanning mobility particle sizer (SMPS), and optical particle sizer (OPS), which combined measure particles of a size range 6-500nm. Tests were done using the NIST standard test part and a honeycomb infill cube. Results from this study show that particle emissions are closely related to filament residence time in the extruder while less related to extruding speed. An initial spike of particle concentration is observed immediately after printing, which is likely a result of the long time required to heat the extruder and bed to the desired temperature. Upon conclusion of this study, it is theorized that particles may be formed through vapor condensation and coagulation after being released into the surrounding environment.

With confirmation of FDM ultrafine particle emission at notable concentrations, an effort was consequently placed on diagnosing the primary cause of emission and energy consumption based on developed hypotheses. Experimental data suggests that particle emission is mainly the result of condensing and agglomerating semi-volatile organic compounds. The initial emission spike occurs when there is dripping of semi-liquid filament from the heated nozzle and/or residue left in the nozzle between prints; this supports the previously stated hypothesis regarding residence time. However, the study shows that while printing speed and material flow influence particle emission rate, the effects from these factors are relatively insignificant. Power profile analysis indicates that print bed heating and component temperature maintaining are the leading contributors to energy consumption for FDM printers, making time the primary variable driving energy input.

To better understand the severity of FDM emissions, further investigation is necessary to diligence the makeup of the process output flows. By collecting exhaust discharge from a Makerbot Replicator 2x printing ABS filament and diffusing it through a type 1 water solution, we are able to investigate the chemical makeup of these compounds. Additional exploration is done by performing a filament wash to investigate emissions that may already be present before extrusion. Using solid phase micro-extraction, contaminants are studied using gas chromatography mass spectrometry (GCMS) thermal desorption. Characterization of the collected emission offers more comprehensive knowledge of the environmental and human health impacts of this AM process.

Classification of the environmental performance of various manufacturing technologies can be achieved by analyzing their input and output material, as well as energy flows. The unit process life cycle inventory (UPLCI) is a proficient approach to developing reusable models capable of calculating these flows. The UPLCI models can be connected to estimate the total material and energy consumption of, and emissions from, product manufacturing based on a process plan. The final chapter focuses on using the knowledge gained from this work in developing UPLCI model methodology for FDM, and applying it further to the second most widely used AM process: stereolithography (SLA). The model created for the FDM study considers material input/output flows from ABS plastic filament. Energy input/output flows come from the running printer, step motors, heated build plate, and heated extruder. SLA also fabricates parts layer by layer, but by the use of a photosensitive liquid resin which solidifies when cured under the exposure of ultraviolet light. Model material input/output flows are sourced from the photosensitive liquid resin, while energy input/output flows are generated from (i) the projector used as the ultraviolet light source and (ii) the step motors. As shown in this work, energy flow is mostly time dependent; material flows, on the other hand, rely more on the nature of the fabrication process. While a focus on FDM is asserted throughout this study, the developed UPLCI models show how conclusions drawn from this work can be applied to different forms of AM processes in future work.

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BEIDARI, MOHAMED, and 裴牧和. "Integrated Study of Energy Consumption CO2 Emissions and Input-Output Life Cycle Assessment for the Electricity Sector in South Africa." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8ef6fg.

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博士
國立成功大學
環境工程學系
106
South Africa (SA) is the most industrialized and developed country in Africa. According to British Petroleum (BP) Statistical Review of Energy (2014), coal accounted for 72% of South Africa's total primary energy consumption, followed by oil (22%), natural gas (3%), nuclear (3%), and renewables (less than 1%) in 2013. This dependency on coal put SA as the leading carbon dioxide emitter in Africa and the 13th largest in the world, according to the latest U.S. Energy Information Administration report (EIA, 2015). Coal combustion is generally more carbon-intensive than the burning natural of gas or petroleum for electricity. Coal represents more than 90% of the electricity generated in South Africa, which accounts for about 99% of CO2 emissions from electricity sector (IEA data, 2015). In 2013, the electricity sector was the largest source of SA’s CO2 emissions, accounting for about 60% of the SA total as shown in Figure 1. Carbon dioxide emissions from electricity have increased by 64% since 1990 as electricity demand has grown and as coal has remained the dominant source for generation. Therefore, the purpose of this study is firstly to evaluate the occurrence of decoupling of CO2 emissions from the Gross Domestic Product (GDP) in South Africa (SA) for the period of 1990 to 2012 by using the Organization for Economic Cooperation and Development (OECD) and Tapio methods, and to identify the primary CO2 emissions driving forces by the Kaya identity. Then, the Log Mean Divisia Index (LMDI) is applied to analyze the influence of the factors which ruled electricity generation-related CO2 emission in SA over the period 1990–2013. For further investigations, the input-output linkage and multiplier methods have been applied to investigate the interrelationships of the 18 sectors’ input-output tables for the years 1995, 2000, 2005, 2010 and 2012, and to measure the total impact of their energy commodity input coefficients and CO2 emissions output coefficients for the year 2012. Finally, the Input-Output Life Cycle Assessment (IO-LCA) was employed to evaluate the potential global warming and other environmental impacts from the electricity generation and related industry. The impact 2002+ model was adopted from SimaPro 7.3.3 to analyze environmental impacts. The methodology also explores the level of uncertainty of various impact categories. Monte Carlo simulation is used to analyze the uncertainties associated with Life Cycle Inventory (LCI), Life Cycle Impact Assessment (LCIA), and the normalization and weighting processes. The uncertainty of the environmental performance for major impact categories and damage categories are also calculated and compared. The results from the decoupling investigation show a strong decoupling during the period of 2010–2012, which is considered as the best development situation. From 1994–2010 SA had a weak decoupling; while during the period 1990–1994, the development in SA presents an expansive negative decoupling state. The comparison of the OECD and Tapio’s methods shows well-correlated results but differs in their applications; however, the OECD method appears as the simpler one. The results of the Kaya identity demonstrate that the increase in population, GDP per capita and deteriorating energy efficiency were the main primary driving forces for the increase of CO2 emissions. Concerning the LMDI, results show that the electricity generation intensity effect plays the dominant role in decreasing CO2 emissions. However, the effect of economic activity is the major determinant that contributes to increasing CO2 emissions. Regarding the input-output linkage and multiplier analysis, results reveals that the electricity sector has a weak linkage with others sectors, which means it is mostly independent of other sectors. In another words, it does not induce and enable economic growth. Moreover, two sectors, namely Chemical and Petrochemical Industries and Basic Metals, were found as key sectors in SA’s economy in 1995, 2000 and 2012. In 2005 and 2010, only Chemical and Petrochemical Industries was the most important sector in SA. Additionally, Commercial and Public Services was the strongest forward linkage sector in SA. Our findings also showed that the electricity sector was the main direct monetary energy consumer and CO2 emitter and therefore the most dominant source in terms of energy and CO2 intensities among all the 18 sectors in SA. Furthermore, our investigation of the direct and indirect effects on energy consumption and CO2 emissions indicated that both total of direct energy consumption and CO2 emissions were higher than both total indirect energy consumption and CO2 emissions. Finally, the normalization results from IMPACT 2002+ demonstrates that the electricity power generation sector and the coal mining sector were respectively the two main sectors which had the highest environmental load during the study period. It also showed that the resources were the major environmental damages, followed by human health and climate change over those five years. In contrast, the ecosystem quality was barely affected, and their impact values were the lowest among those 4 damage categories over the study period. The cumulative of normalized impact values revealed that the respiratory inorganics, the non-renewable energy, and the global warming in that order were the most significant environmental impacts from the South Africa’s electricity generation sector. Results of direct and indirect effects revealed that the electricity sector had the highest direct impact on human health, followed by climate change and ecosystem quality in 1995, 2000, 2005, 2010 and 2012. In contrast, the resources impact was mainly caused from the indirect effect produced by other relevant sectors such as coal mining sector for three years. Results also pointed out that the Particulates, 〈 10 um mainly emitted from the electricity sector was the major substance that contributed to respiratory inorganics impact category and the human health damage category. The global warming impact category was largely caused by carbon dioxide from non-renewable energy which was as a result of the use of coal and unspecified energy at the power plant for the electricity generation. Thus, the electricity sector was the major emitter of carbon dioxide and had the highest share of the substances responsible of the global warming impact category. Moreover, the non-renewable energy is mainly caused by coal and unspecified energy with the coal mining and the electricity sectors being the main non-renewable energy consumers. The particulate matter PM10 and the carbon dioxide were identified as air pollutants with major health and environmental concerns. The results of the IO-LCA specified that majority of these two substance emissions were emitted from the electricity sector. Thus, Eskom (SA’s electricity national distributor) and the SA’s government should take actions to reduce more PM10 and CO2 emissions by finding strategies to decrease the amount of coal consumed to produce electricity, or shift to renewable. However, other substances such as Sulfur dioxide, Arsenic, Barium, Nitrogen oxides, Ammonia, Dioxin, 2,3,7,8 Tetrachlorodibenzo-p-, Dinitrogen monoxide, Sulfur hexafluoride and Methane which are also pollutants with major health and environmental concerns, shouldn’t be ignored. The results of the Monte Carlo simulation of the top 12 sectors showed that the standard deviations of the respiratory inorganics, global warming, climate change and human health do not widely vary from their means with coefficients of variation less than 32% overall. This point out some of level of consistency with the input data. The results also indicated that the score for non-renewable energy and resources have very high uncertainty compare to Global warming and Respiratory inorganics especially in 1995 and 2012 where the coefficients of variation were respectively 104% and 115%. That revealed the standard deviation varies widely from the mean. Finally, the simulation of Monte Carlo on Single score of the top 12 sectors presented a coefficient of variation less than 60% each year of the study, which means the standard deviation does not vary widely from the mean. Therefore, the results of this study revealed some of level of reliability with the input data overall. In addition to the results of this study, some potential suggestions on reducing the energy consumption and CO2 emissions deduced from this study are discussed.

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Themba, Nomathemba. "Control of stack emissions using hydrated lime injections during incineration of healthcare risk waste : a case study of Biomed in Benoni." Diss., 2020. http://hdl.handle.net/10500/26918.

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Incineration is still a widely utilised method for treating healthcare risk waste in the Republic of South Africa. As much as incinerators are needed, the fact that they are still a critical source of hazardous toxic air pollutants that are not easy to manage cannot be disregarded. The Ministry of Environmental Affairs has promulgated a new regulation for General and Hazardous Waste Thermal Treatment. This exceedingly stringent air pollution legislation requires that existing incinerators be modified or redesigned to meet the new air quality standards, or face closure in the event that they fail to comply. The regulation contains strict emission requirements for concentrations of stack gases such as CO2, NO2, NOx, HCl, HF, CO, SO2, as well as TOC and PM. To be certain that emissions are within the standard, incineration facilities are instructed to reduce the acid gas emissions and to have permanent on-line monitoring equipment for stack testing of regulated pollutants. Since the promulgation of the new legislation in April 2015, none of the incinerators in South Africa has been able to achieve the new requirements. This study, based on the quantitative approach, was conducted in search of a cost-effective method of controlling acid gas emissions from incinerators without major adjustments to the plants. During the study, 60 kg of sorbacal Ca(OH)2 was injected into a lime feeder every day. A variable speed drive was used to inject Ca(OH)2 into the furnace continuously at a rate of between 2.5 kg/h and 3.5 kg/h. The temperature was maintained between 850°C and 1200°C with the use of four gas burners. Two manual blowers were utilised to ensure a continuous flow of Ca(OH)2 into the reaction chamber and filtration system. Comparative analysis was done to compare gas emission levels before and after the use of hydrated lime. Descriptive statistics were used to compute the mean, frequency and percentages, while Wilcoxon sign rank test established whether hydrated lime was significant in reducing gaseous emissions or not. Wilcoxon sign rank test showed a statistically significant difference (P<0.05) in the reduction of all gaseous emissions using hydrated lime, except particulate matter where there was a significant increase in emissions. This technology was able to achieve high removal efficiency of 97% for HCl, 86% for HF, 83% for NOx, 87% for SO2 and 74% for NO2. The optimum temperature for SO2 and NOx was 1020°C. For HCl it was between 1190°C and 1200°C, and for NO2 it was between 1120°C and 1200°C. The amount of particulate matter increased along with the concentration of the Ca(OH)2 injections. Ca(OH)2 was found to be cost effective in the controlling and capturing of gaseous emissions. It is recommended that combustion requirements, such as heat, oxygen and turbulence, be considered to reduce the amount of gases generated during the incineration of healthcare risk waste. It is also recommended that electrostatic precipitators be used instead of fabric filters to improve the efficiency of capturing the particulate matter.
Environmental Sciences
M.Sc. (Environmental Science)

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Hsieh, Chang-Jun, and 謝長潤. "Life Cycle Cost Analysis and the Comparative of Carbon Dioxide Emissions of Concrete and Asphalt Pavements in Taiwan Freeway Network: A Case Study." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/67009918407936718526.

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碩士
國立臺灣大學
土木工程學研究所
104
The 9.25 km (5.8 mile) Daxi-Longtan section of National Freeway No. 3 was the first large scale concrete pavement of major highway in Taiwan. Based on the recorded maintenance data for the past 22 years since its opening, concrete pavement has shown much lower frequency of maintenance and consequently lower maintenance costs than that of asphalt pavement. The major maintenance works involve diamond grinding, full depth and partial depth patch, joints resealing, and a few slab replacements. This study conducted life cycle cost analysis (LCCA) and life cycle assessment (LCA) on the concrete pavement and two conjunctive sections of asphalt pavement with the same length, one at each end of the concrete pavement section. The LCCA approach considers not only direct agency costs (initial construction costs and maintenance costs) but also extra user costs induced by congestion at maintenance work zone. The LCA mainly focused on CO2 emission of paving materials preparation, transportation, and construction equipment operation. The results show that for the first 22 years, the ratio of life cycle costs of concrete pavement over that of asphalt pavement is 1.11. On the other hand, the ratio of CO2 emission of concrete pavement over that of asphalt pavement is 1.34. Researchers also conducted the forecasting analysis for a total life of 40 years. It is found that both types of pavement have almost the same life cycle costs and CO2 emission. Since a relatively large portion of the user costs and CO2 emission of concrete pavement are caused by traffic congestion during maintenance, it is believed that both extra user costs and CO2 emission can be reduced significantly if the fast-track concrete pavement maintenance method can be adopted.

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Dissertations / Theses on the topic 'Line emission study'

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