Дисертації з теми "NIR emission"
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1
Piecuch, Scott. "A Fast NIR Spectrometer for Examining Explosive Events: Emission of PETN Based Explosives and H₂O Absorption Method Feasibility." [Milwaukee, Wis.] : e-Publications@Marquette, 2009. http://epublications.marquette.edu/theses_open/13.
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2
Dahal, Dipendra Dahal. "SYNTHESIS AND CHARACTERIZATION OF NOVEL EXCITED STATE INTRAMOLECULAR PROTON TRANSFER (ESIPT) CYANINE DYES WITH NEAR INFRARED (NIR) EMISSION FOR BIOLOGICAL APPLICATIONS." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1567644552737644.
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3
Tietze, Remo, Rene Panzer, Thorben Starzynski, Chris Guhrenz, Florian Frenzel, Christian Würth, Ute Resch-Genger, Jan J. Weigand, and Alexander Eychmüller. "Synthesis of NIR-emitting InAs-based core/shell quantum dots with the use of tripyrazolylarsane as arsenic precursor." Wiley-VCH Verlag GmbH & Co. KGaA, 2018. https://tud.qucosa.de/id/qucosa%3A33887.
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Tris(3,5-dimethylpyrazolyl)arsane (1) is introduced as an low-cost and convenient to handle arsenic precursor for the straight forward synthesis of InAs quantum dots (QDs). Transamination of 1 with the solvent oleylamine (OLAH) gives trioleylarsane (As(OLA)3) which in the presence of the reducing agents DIBAL-H or P(OLA)3 yields InAs QDs via a typical hot injection approach. The size of the obtained InAs core QDs are tuned by varying the reaction time, the amount of the applied reducing agent, or even more effectively by changing the indium and/or zinc halide precursors, InX3 and ZnX2 (Cl, Br, or I). Passivation of the resulting InAs particles with a protective ZnS or ZnSe shell results in improved photoluminescence (PL) of the core/shell QDs covering a spectral range between 600–1150 nm.
4
Tungulin, Dmitry. "Towards NIR emission: 2-(1H-tetrazol-1-yl)pyridine as versatile ligand for the synthesis of two new families of cationic and neutral Ir(III) complexes." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11948/.
Повний текст джерелаАнотація:
In the last decades, cyclometalated Ir(III) complexes have drawn a large interest for their unique properties: they are excellent triplet state emitters, thus the emission is phosphorescent in nature; typically high quantum yields and good stability make them good candidates for luminescent materials. Moreover, through an opportune choice of the ligands, it is possible to tune the emission along the whole visible spectra. Thanks to these interesting features, Ir(III) complexes have found different applications in several areas of applied science, from OLEDs to bioimaging. In particular, regarding the second application, a remarkable red-shift in the emission is required, in order to minimize the problem of the tissue penetration and the possible damages for the organisms.
With the aim of synthesizing a new family of NIR emitting Ir(III) complexes, we envisaged the possibility to use for the first time 2-(1H-tetrazol-1-yl)pyridine as bidentate ligand able to provide the required red-shift of the emission of the final complexes. Exploiting the versatility of the ligand, I prepared two different families of heteroleptic Ir(III) complexes. In detail, in the first case the 2-(1H-tetrazol-1-yl)pyridine was used as bis-chelating N^N ligand, leading to cationic complexes, while in the second case it was used as cyclometalating C^N ligand, giving neutral complexes. The structures of the prepared molecules have been characterised by NMR spectroscopy and mass spectrometry. Moreover, the neutral complexes’ emissive properties have been measured: emission spectra have been recorded in solution at both room temperature and 77K, as well as in PMMA matrix. DFT calculation has then been performed and the obtained results have been compared to experimental ones.
5
Bu, Lulu. "Synthesis of NIR Dyes and Nanoparticles for in vivo Bioimaging and Dicyanovinyl Dyes for Primary Amine Detection." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN086.
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L’imagerie de fluorescence et l'imagerie photo-acoustique (PA) sont deux outils puissants pour la visualisation des tissus et organes biologiques de manière non invasive. Toutefois, ces technologies sont actuellement limitées par le manque d'agents de contraste efficaces. Utiliser des longueurs d’onde de domaine du proche infrarouge (NIR, 650-900 nm), dont l'absorption et la diffusion dans les organismes est relativement faible, permet une imagerie in vivo plus profonde, induit moins d’auto-fluorescence et apporte un bon rapport signal/bruit. Par conséquent, la conception et la synthèse de nouveaux colorants organiques NIR efficaces revêt une importance fondamentale pour l’imagerie de fluorescence ou photo-acoustique. L'encapsulation de colorants organiques dans des nanoparticules dispersibles dans l'eau présente un grand potentiel en imagerie bio-optique, offrant les avantages d'une haute luminosité, d'une bonne photo-stabilité, d'une excellente biocompatibilité et d'une capacité potentielle de ciblage, etc. Notre objectif principal dans cette thèse est de synthétiser de nouvelles molécules organiques pouvant servir d’agents de contraste pour l'imagerie in vivo par fluorescence ou PAFluorescence and photoacoustic (PA) imaging are both powerful tools for visualization of biological tissues and organs in non-invasive ways. However, these technologies are limited by the lack of efficient contrast agents. NIR light (650-900 nm) with relatively low absorption and scattering in organisms allows for deeper in vivo imaging, lower auto-fluorescence as well as a good signal to noise ratio. Hence, design and synthesis of efficient NIR organic dyes are of great significance for fluorescence or PA bio-imaging. Meanwhile, encapsulation of organic dyes in nanoparticles dispersible in water present great potential in bio-optical imaging, offering the advantages of high brightness, good photo-stability, excellent biocompatibility and potential targeting ability, etc. Our main goal in this thesis is to synthesize novel organic contrast agents for in vivo fluorescence or PA imaging
6
Khan, Kamruzzaman. "NiOx Based Device Structures." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1469380686.
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7
Behnke, Lucie [Verfasser], Jürgen [Akademischer Betreuer] Kirschner, Wolf [Akademischer Betreuer] Widdra, and Markus [Akademischer Betreuer] Donath. "Electron pair emission from NiO and metal surfaces / Lucie Behnke. Betreuer: Jürgen Kirschner ; Wolf Widdra ; Markus Donath." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2014. http://d-nb.info/1058587145/34.
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8
Sirigu, Lorenzo. "Stimulated emission and lasing in one-dimensional electronic systems /." [S.l.] : [s.n.], 2002. http://library.epfl.ch/theses/?nr=2604.
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9
ARTIZZU, FLAVIA. "Light conversion processes in lanthanide-based molecular materials." Doctoral thesis, Università degli Studi di Cagliari, 2015. http://hdl.handle.net/11584/266857.
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This work is mainly focused on the investigation and processing of luminescent molecular complexes of lanthanide ions (Ln), for the development of efficient near infrared (NIR)-emitting materials. In the light of a detailed understanding of the chemical/photophysical properties of the special class of lanthanide quinolinolato complexes, as prototype molecular materials for NIR applications, two main aspects have been taken into consideration for a progress in this field: i) (multi-) functional NIR-emissive heterolanthanide complexes and ii) lanthanide-doped sol-gel glasses as NIR-emissive optical materials.
Heterometallic assemblies, containing two or more different lanthanide cations as carriers of distinctive functionalities, represent promising materials where different physical properties can coexist or be in interplay thanks to intermetallic communication. A thorough discussion on heterolanthanide assemblies, pointing out the general strategies to achieve the desired (multi-) functionalities in these systems, is provided herein.
In this framework, heterolanthanide Er/Yb systems have attracted significant interest for Er3+ sensitization through resonance energy transfer (RET) from Yb3+ leading to enhancement of Er3+ NIR emission at 1.5 μm in glass host Yb-Er co-doped optical fiber amplifiers. A strategy to achieve composition control and homogeneity in such materials resorts to the encapsulation of Er and Yb in the same molecule to afford intermetallic communication between lanthanide ions sitting at short distance in a discrete polynuclear architecture. Fully efficient Yb-to-.Er RET at molecular level is firstly demonstrated in the mixed-lanthanide Yb2ErQ9 complex (Q = quinolinol ligand), and, as an extension of these studies, the investigation of the full photocycle leading to narrow-band NIR emission in a series of heterolanthanide ErxYb3-x quinolinolato compounds, on variation of metal composition and molecular stoichiometry, has been performed. Moreover, the first example of a tri-lanthanide discrete polynuclear molecule containing three NIR-emissive lanthanide ions: Nd3+, Yb3+ and Er3+, is presented. The NdYbErQ9 complex was investigated as a potential broad-band NIR emitter where the intensities of the three different main emissions from each lanthanide ion can be finely tuned on varying metal composition.
The investigation of the processing potential of luminescent lanthanide complexes through doping into inorganic or polymeric host matrixes is of crucial interest for the development of optical devices (amplifiers, optical waveguides, OLEDs, etc.). To this purpose, studies on the incorporation of an Yb quinolinolate complex into a silica sol-gel glass, with a thorough account of the photophysical properties of this hybrid material, have been performed. Promising results on silica thin films doped with heterolanthanide Er/Yb quinolinolates are also presented as a molecular approach to achieve controlled light conversion in NIR-emissive optical materials.
10
Alfieri, Ezio. "Emissions-controlled diesel engine /." Zürich : ETH, 2009. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18214.
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11
Leupin, Andreas. "Spectral emission and improvement of technical infrared radiators /." [S.l.] : [s.n.], 1989. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8942.
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12
Schulthess, Reto von. "Die Emission von Lachgas (N₂O) in denitrifizierenden Belebungsanlagen /." Zürich, 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10790.
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13
Sirringhaus, Henning. "Ballistic-electron-emission microscopy on epitaxial CoSi₂ / Si interfaces /." Zürich, 1995. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11173.
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14
Gaillet, Laurent. "Etude de la synergie déformation-oxydation lors du fluage d'un système NI/NIO sous oxygène A 550°C. Influence de la nature cristallographique du substrat de nickel et du mode d'élaboration de la couche d'oxyde NIO." Compiègne, 2000. http://www.theses.fr/2000COMP1281.
Повний текст джерелаАнотація:
Des expériences d'oxydation sous contrainte ont été effectuées dans une installation permettant à la fois la détermination des paramètres mécaniques, le suivi de la dégradation des strates d'oxyde par émission acoustique et l'analyse diffusionnelle ( 1 8o). L'étude a porté sur divers systèmes de nickel oxydes (polycristaux, monocristaux, oxydes déposés) sollicités en fluage, sous oxygène, à 550°C. La microstructure des films d'oxyde de NIO élaborés par voie thermique est duplex alors que celle des oxydes NIO déposés présente une seule strate. Dans tous les cas, un endommagement (fissuration périodique, décollements) des films d'oxyde est constate (métallographie, émission acoustique) lorsque une contrainte en fluage est appliquée. Une influence de la cristallographie du substrat monocristallin sur les mécanismes et les vitesses de déformation en fluage a été mise en évidence. De plus, l'influence du film d'oxyde NIO sur ces paramètres mécaniques a été aussi observée. Des expériences de relaxation de contrainte après le fluage ont permis de scinder la contrainte appliquée en deux types (relaxée et interne I). On remarque également une absence d'influence de la cristallographie du substrat pour les oxydes déposés avec des lois et des vitesses de fluage quasiment identiques. Une modélisation de ces systèmes NI/NIO a permis de constater que les contraintes dans le film d'oxyde sont en compression après fissuration de celui-ci. Concernant la diffusion, l'application d'une contrainte externe a une influence sur le coefficient de diffusion de l'oxygène dans NIO pour les oxydes thermiques. Par contre, la diffusion de l'oxygène est insensible à l'application d'une contrainte en fluage dans le cas des oxydes NIO élaborés par dépôt. La notion de force motrice complémentaire sous la forme d'une évolution des défauts ou d'origine mécanique a été recherchée.
15
Braz, Danilo Cavalcante. "Tratamento termoqu?mico do tit?nio auxiliado por plasma de ar - N2 - O2." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12701.
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Discs were grade II cp Ti oxynitride by plasma of Ar - N2 - O2 using different proportions of individual gases. These ratios were established from analysis of optical emission spectroscopy (OES) of plasma species. The proportions that resulted in species whose spectra showed an abrupt change of light intensity were chosen for this study. Nanohardness tests revealed that there was a correlation between the intensity of N2 + species with the hardness, because the treatments where they had a higher intensity, obtained a higher value nanohardness, although the crystalline phases have remained unchanged. With respect to topography, it was observed that in general, the surface roughness is related to the intensities of plasma species, because they may have different values depending on the behavior of the species. Images obtained by optical microscopy revealed a surface with grains of different colors to optical reflectance showed a peak of reflection in the red area. Measures the contact angle and surface tension showed hydrophilic properties and hydrophilic with little variation of polar and dispersive components of surface tension
Discos de tit?nio cp grau II foram oxinitretados por plasma de Ar - N2 - O2 usando diferentes propor??es de gases individuais. Essas propor??es foram estabelecidas a partir de an?lises de espectroscopia de emiss?o ?ptica (OES) das esp?cies do plasma. As propor??es que resultaram em espectros cujas esp?cies apresentaram varia??o abrupta de intensidade luminosa foram escolhidas para o presente trabalho. Os ensaios de nanodureza revelaram que houve uma rela??o entre a intensidade da esp?cie N2 + com a dureza, pois para os tratamentos onde estas apresentaram maior intensidade, obteve-se maior valor de nanodureza, embora as fases cristalinas tenham se mantido inalteradas. Com rela??o ?s topografias, observou-se que de um modo geral, a rugosidade superficial est? relacionada com as intensidades das esp?cies do plasma, pois estas podem apresentar valores diferentes dependendo do comportamento das esp?cies. Imagens obtidas por microscopia ?ptica revelaram uma superf?cie com gr?os de diferentes cores e a reflet?ncia ?ptica mostrou um pico m?ximo de reflex?o na regi?o do vermelho. As medidas de ?ngulo de contato e tens?o mostraram superf?cies com propriedades hidrof?licas e pouco hidrof?licas com varia??o das componentes polar e dispersiva da tens?o superficial
16
Ruckstuhl, Andreas Franz. "Analysis of the T₂ emission spectrum by robust estimation techniques /." Zürich, 1995. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11170.
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17
Silva, Erika Caitano da. "Emiss?es de N2O do solo de cana-de-a??car plantada com fungicida via solo e fertilizada com ureia." Universidade Federal Rural do Rio de Janeiro, 2015. https://tede.ufrrj.br/jspui/handle/jspui/2052.
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The objective of this study was to evaluate the efficiency of a fungicide of the strobilurin group in reducing soil N2O production, a potent greenhouse gas, and a possible positive effect on the N use efficiency by sugarcane. Laboratory studies were conducted to evaluate the effect of fungicide in soil fertilized with N on N2O emissions, as well as greenhouse and field experiments to study the fungicide as controller of urea and ammonium nitrate induction of N2O emissions and as an enhancer of fertilizer N use efficiency by sugarcane. In addition to the monitoring of soil N2O fluxes with static chambers sugarcane leaves were collected for analysis of soluble forms of N and nitrate reductase activity together with plant parameters to estimate yield and the efficiency of fertilizer N use. Laboratory tests revealed the fungicide was capable of reducing soil N2O emissions. Regardless of N source, the fungicide did not affect the analyses of enzymes and plant N fractions in sugarcane, but there was a downward trend of N2O fluxes in the soil treated with urea in the greenhouse experiment. In the field experiment, N2O fluxes were 6 to 89 ?g N m-2h-1, 24 to 795 ?g N m-2h-1 and 27 to 508 ?g N m-2h-1 respectively to the control (no added N), urea and urea + fungicide treatments, indicating that N2O emissions were reduced in approximately 30% by the fungicide. The treatment with ammonium nitrate did not induce N2O emissions from soil. There was no significant difference between treatments in all analyses of soluble fractions and enzyme activity. Based on the dimensions of stalks, sugarcane yield was estimated at 190 Mg ha-1for the control treatment (without added N) and at 238 Mg ha-1 for urea treatment. The application of fungicide had no effect on yield. The use of fungicide reduced soil N2O emissions, but does not induce greater N use efficiency by sugarcane
O objetivo deste trabalho foi avaliar a efici?ncia de fungicida do grupo das estrobilurinas na redu??o da produ??o de N2O no solo, um potente g?s de efeito estufa, al?m de poss?veis efeitos positivos na efici?ncia de uso de N pela cana-de-a??car. Foram conduzidos estudos em laborat?rio para avaliar o efeito do fungicida em solo fertilizado com N sobre as emiss?es de N2O, assim como um ensaio em casa de vegeta??o e outro em campo, onde se estudaram a ureia e o nitrato de am?nio, tratados ou n?o com fungicida, sobre as emiss?es de N2O e indicadores de efici?ncia de uso de N pela cana-de-a??car. Al?m do monitoramento dos fluxos de N2O com c?maras est?ticas, foram tamb?m coletadas folhas da cultura para an?lise das fra??es sol?veis de N e an?lise da enzima nitrato redutase, incluindo-se tamb?m a estimativa da produtividade e efici?ncia do uso de N. Os ensaios de laborat?rio mostraram que o fungicida aplicado ao solo reduz emiss?es de N2O. No ensaio em casa-de-vegeta??o, a an?lise de enzimas e fra??es de N na cana-de-a??car n?os e alteraram com o uso do fungicida, independente da fonte de N, mas houve tend?ncia de redu??o dos fluxos de N2O no solo tratado com ureia. No ensaio de campo, os fluxos de N2O foram de 6 a 89 ?g N m-2h-1, 24 a 795 N m-2 h-1 e 27 a 508 N m-2 h-1respectivamente para os tratamentos controle (sem adi??o de N), ureia e ureia +fungicida, indicando queda nas emiss?es de N2O de aproximadamente 30% no tratamento com fungicida.O tratamento com nitrato de am?nio n?o induziu emiss?es de N2O do solo.N?o houve diferen?a significativa entre os tratamentos em todas as an?lises das fra??es sol?veis e tamb?m na an?lise enzim?tica. A produtividade de colmos (TCH), estimada a partir das dimens?es dos colmos, variou significativamente de 190 Mg ha-1, no tratamento controle (sem adi??o de N), para 238 Mg ha-1, no tratamento com ureia, por?m a aplica??o do produto n?o influenciou na produ??o da cultura. O uso de fungicida reduz emiss?es de N2O, por?m n?o induz maior efici?ncia de uso de N pela cana-de-a??car
18
Oakley, Jonathan David. "Magnetic resonance imaging based correction and reconstruction of positron emission tomography images /." Zürich, 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13484.
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Nordstrom, Richard Alan. "Acoustic emission characterization of microstructural failure in the single fiber fragmentation test /." Zürich, 1996. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11402.
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Silva, Bruno Felipe Costa da. "Diagn?stico de plasma de c?todo oco: an?lise da a??o de plasma de arg?nio e Ar-H2 para a deposi??o de filmes finos de tit?nio em p?s-descarga." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15706.
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Plasma DC hollow cathode has been used for film deposition by sputtering with release of neutral atoms from the cathode. The DC Plasma Ar-H2 hollow cathode currently used in the industry has proven to be effective in cleaning surfaces and thin film deposition when compared to argon plasma. When we wish to avoid the effects of ion bombardment on the substrate discharge, it uses the post-discharge region. Were generated by discharge plasma of argon and hydrogen hollow cathode deposition of thin films of titanium on glass substrate. The optical emission spectroscopy was used for the post-discharge diagnosis. The films formed were analyzed by mechanical profilometry technique. It was observed that in the spectrum of the excitation lines of argon occurred species. There are variations in the rate of deposition of titanium on the glass substrate for different process parameters such as deposition time, distance and discharge working gases. It was noted an increase in intensity of the lines of argon compared with the lines of titanium. Deposition with argon and hydrogen in glass sample observed a higher rate deposition of titanium as more closer the sample was in the discharge
O Plasma DC de catodo oco vem sendo utilizado para a deposi??o de filmes atrav?s de sputtering com libera??o de ?tomos neutros do c?todo. O Plasma DC de Ar-H2 de catodo oco usado atualmente na ind?stria tem demonstrado ser eficiente na limpeza de superf?cies e deposi??o de filmes finos quando comparado ao plasma de arg?nio. Quando desejamos evitar os efeitos do bombardeamento i?nico da descarga no substrato, utiliza-se a regi?o de p?s-descarga. Geraram-se descargas por plasma de arg?nio e hidrog?nio em catodo oco para deposi??o de filmes finos de tit?nio em substrato de vidro. A espectroscopia de emiss?o ?tica foi empregada para o diagn?stico na p?s-descarga. Os filmes formados foram analisados atrav?s da t?cnica de perfilometria mec?nica. Observou-se que no espectro das linhas de arg?nio ocorreu excita??o de esp?cies. Verificaram-se varia??es para a taxa de deposi??o do tit?nio sobre o substrato de vidro para diferentes par?metros do processo como: tempo de deposi??o, dist?ncia da descarga e gases de trabalho. Contatou-se um aumento da intensidade das linhas de arg?nio quando comparadas com as linhas de tit?nio. Para deposi??o com Arg?nio e hidrog?nio em amostra de vidro observou uma maior taxa deposi??o de tit?nio quanto mais pr?xima a amostra se encontrava da descarga
21
Nascimento, Igor Oliveira. "Constru??o de um aparato experimental para monitoramento in situ da deposi??o de filmes finos de tit?nio por magnetron sputtering." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12805.
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Previous issue date: 2011-12-09The technique of surface coating using magnetron sputtering is one of the most widely used in the surface engineering, for its versatility in obtaining different films as well as in the micro / nanometric thickness control. Among the various process parameters, those related to the active species of the plasma are of the most fundamental importance in the mechanism and kinetics of deposition. In order to identify the active species of the plasma, parameters such as gas flow, pressure and density of electric power were varied during titanium coating on glass substrate. By flowing argon gas of 10, 20, 30, 40 and 50 sccm (cubic centimeters per minute) for each gas flow a sequential scan of the electric current of 0.10, 0.20, 0.30, 0.40 , 0.50 A. The maximum value of 0.50 A was chosen based both on literature data and on limitations of the equipment. The monitoring of plasma species present during the deposition was carried out in situ by the technique of optical emission spectroscopy (OES) through the spectrometer Ocean Optics USB2000 Series. For this purpose, an apparatus was developed to adapt the OES inside the plasma reactor to stay positioned closest to the target. The radiations emitted by the species were detected by an optical fiber placed behind the glass substrate and their intensities as a function of wavelength were, displayed on a monitor screen. The acquisition time for each condition of the plain parameters was related to the minima of spectral lines intensities due to the film formed on the substrate. The intensities of different emission lines of argon and titanium were then analyzed as a function of time, to determine the active species and estimate the thickness of the deposited films. After the deposition, the coated glasses thin films were characterized by optical transmittance through an infrared laser. It was found that the thickness and deposition rate determined by in situ analysis were consistent with the results obtained by laser transmittance
t?cnica de revestimento superficial utilizando magnetron sputtering ? uma das mais utilizadas pela engenharia de superf?cie, pela sua versatilidade na obten??o de diferentes filmes bem como no controle micro/nanom?trico de sua espessura. Dentre os v?rios par?metros do processo, aqueles relacionados com as esp?cies ativas do plasma s?o de fundamental import?ncia no mecanismo e cin?tica da deposi??o. Com o objetivo de identificar as esp?cies ativas do plasma, par?metros como fluxo de g?s, press?o de trabalho e densidade de pot?ncia el?trica foram variados durante o revestimento de tit?nio em substrato de vidro. Foi utilizado arg?nio com fluxos de 10; 20; 30; 40 e 50 sccm (cent?metro c?bico por minuto) e para cada fluxo de g?s uma varredura sequencial da corrente el?trica de 0,10; 0,20; 0,30; 0,40; 0,50A (amp?res). O valor de m?ximo de 0,50A foi escolhido com base em dados da literatura e limita??es do equipamento. O monitoramento das esp?cies do plasma presentes durante a deposi??o foi realizado "in situ", pela t?cnica de espectroscopia de emiss?o ?ptica (EEO) atrav?s do espectr?metro USB2000 Series da Ocean Optics. Para isso um aparato foi desenvolvido para adaptar o EEO dentro do reator de plasma de maneira que ficasse posicionado o mais pr?ximo poss?vel do alvo. As radia??es emitidas pelas esp?cies foram detectadas atrav?s de uma fibra ?ptica colocada por tr?s do substrato de vidro e suas intensidades, em fun??o do comprimento de onda, foram exibidas na tela de um monitor. O tempo de aquisi??o para cada condi??o de par?metro do plasma foi aquele em que a intensidade espectral deca?a para zero, devido ao filme formado no substrato. As intensidades de diferentes linhas de emiss?o de arg?nio e de tit?nio foram ent?o analisadas em fun??o do tempo, para determinar as esp?cies ativas e estimar a espessura dos filmes depositados. Ap?s a deposi??o, os filmes finos que revestiram os vidros foram caracterizados por transmit?ncia optica, atrav?s de um laser no infravermelho. Verificou-se que os valores da espessura e da taxa de deposi??o s?o determinada pela an?lise "in situ", foram coerentes com os resultados obtidos atraves da transmit?ncia por laser
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Edlund, Kajsa, and Ali Ahmad Shahnawazi. "Real-time characterization of fuel by Near-Infrared spectroscopy : Quantitative measurements of moisture content, ash content, heating value, and elemental compositions in solid biofuel mixtures." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-55231.
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The global energy demand supplies mainly from fossil fuels, which is neither sustainable nor environmentally friendly and aims to global warming. Therefore, both more investments in renewable energy sources such as bioenergy are required, as well as new technologies such as carbon capture and storage (CCS) to handle the emissions from existing combined heat and power (CHP) plants. In this degree project, the focus is to determine the moisture content, ash content, heating value, and elemental compositions of solid biofuel mixtures in real-time by utilizing the optical technique of near-infrared (NIR) spectroscopy. A total number of 150 samples of solid biofuel mixtures were prepared and illuminated by NIR light. All spectra of the samples were recorded in a wavenumber range of 12000 cm-1 – 400 cm-1 in a dish on a turn table which was in a moving mode with a speed of 0.5 m/s. Each sample was scanned three times to avoid, or at least minimize the deviation of the spectra and the samples were mixed between each scan to get more reliable representative spectra data. Partial least square regression models were created to analyze the spectra data. A data split was done randomly, 100 for calibration and 50 for validation. Then the data was pre-processed with different methods including multiplicative scatter correction (MSC), standard normal variate (SNV), Savitzky-Golay 1st derivative (SG 1st), Savitzky-Golay 2nd derivative (SG 2nd), and orthogonal signal correction (OSC) to reduce noise and scatter effect. The results of NIR spectra treated by OSC method obtained , RMSE and SE of 0.900, 2.241 and 2.204, respectively for prediction of moisture content, 0.424, 0.913 and 0.922 for prediction of ash content, 0.640, 0.370 and 0.368 for prediction of heating value, respectively. The obtained prediction of , RMSE and SE were 0.687, 0.066 and 0.058 for nitrogen, 0.636, 0.361 and 0.364 for carbon, 0.483, 0.269 and 0.270 for hydrogen, respectively. As the results shows, these models to predict the ash content and hydrogen content has a lower accuracy than what is expected in process modeling while the prediction of moisture content has the highest accuracy.
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Barbosa, Julio Cesar Pereira. "Diagn?stico das esp?cies ativas do plasma usado em tratamentos termoqu?micos do tit?nio." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12774.
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Previous issue date: 2011-04-29Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Plasma diagnostics by Optical Emission Spectroscopy were performed for electrical discharge in three gas mixture respecting the combinations z N2 y Ar x H2, z N2 y Ar x O2 e z N2 y Ar x CH4, in which the indexes z and y systematically vary from 1 to 4 and x varies from 0 to 4, every one has dimension SCCM, resulting in 80 combinations. From the all obtained spectrums, the species CH (387,1 nm), N2+ (391,4 nm), Hβ (486,1 nm), Hα (656,3 nm), Ar (750,4 nm), O (777,4 nm) e O (842,6 nm) were analyzed because of their abundance and importance on the kinetic of reaction from the plasma to surface, besides their high dependences on the gases flows. Particularly interesting z, y and x combinations were chosen in order to study the influence of active species on the surface modification during the thermochemical treatment. From the mixtures N2 Ar O2 e N2 Ar CH4 were chosen three peculiar proportions which presented luminous intensity profile with unexpected maximum or minimum values, denominated as plasma anomaly. Those plasma concentrations were utilized as atmosphere of titanium treatment maintaining constant the control parameters pressure and temperature. It has been verified a relation among luminous intensity associated to N2+ and roughness, nanohardness and O atoms diffusion into the crystalline lattice of treated titanium and it has been seen which those properties becomes more intense precisely in the higher points found in the optical profile associated to the N2+ specie. Those parameters were verified for the mixture which involved O2 gas. For the mixture which involves CH4 gas, the relation was determinate by roughness, number of nitrogen and carbon atoms diffused into the titanium structure which presented direct proportionality with the luminous intensity referent to the N2+ and CH. It has been yet studied the formation of TiCN phases on the surface which presented to be essentially directly proportional to the increasing of the CH specie and inversely proportional to the increasing of the specie N2+
Diagn?sticos de plasma por Espectroscopia de Emiss?o ?ptica foram realizados para descarga el?trica em tr?s misturas gasosas, dentro das seguintes combina??es: z N2 y Ar x H2, z N2 y Ar x O2 e z N2 y Ar x CH4, com os ?ndices z e y variando sistematicamente de 1 a 4 e x de 0 a 4, todos com dimens?o de SCCM, resultando em 80 combina??es. Dos espectros obtidos, foram analisadas as esp?cies CH (387,1 nm), N2+ (391,4 nm), Hβ (486,1 nm), Hα (656,3 nm), Ar (750,4 nm), O (777,4 nm) e O (842,6 nm) por serem mais abundantes e importantes na cin?tica de rea??o do plasma ? superf?cie, al?m de suas altas depend?ncias dos fluxos de g?s. Foram escolhidas combina??es z, y e x, particularmente interessantes para estudar a influ?ncia das esp?cies ativas na modifica??o da superf?cie durante o tratamento termoqu?mico. Das misturas N2 Ar O2 e N2 Ar CH4 foram escolhidas tr?s propor??es peculiares que apresentavam perfis de intensidade luminescente com m?ximos ou m?nimos inesperados classificados aqui como anomalias de plasma. Essas concentra??es de plasma foram utilizadas como atmosfera de tratamento de amostras de tit?nio, mantendo-se constante os par?metros press?o e temperatura. Verificou-se rela??o entre intensidade luminosa associada ? esp?cie N2+ e a rugosidade, nanodureza e a difus?o do oxig?nio na rede cristalina do tit?nio tratado e viu-se que essas propriedades se intensificam precisamente nos pontos de m?ximo encontrados no perfil ?ptico dessa esp?cie. Esses par?metros foram verificados para mistura que envolvia o g?s O2. Para a mistura em que se fez presente o g?s CH4, a rela??o foi determinada por meio da rugosidade, n?mero de ?tomos de nitrog?nio e carbono difundidos no tit?nio, que apresentou proporcionalidade direta com a intensidade luminosa referente ?s esp?cies N2+ e CH. Ainda foi estudada a forma??o de fases TiCN na sua superf?cie, que essencialmente se mostra diretamente proporcional ao crescimento da esp?cie CH e inversamente proporcional ao crescimento da esp?cie N2+
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Frazer, Bradley. "Synchrotron X-ray PhotoElectron Emission spectroMicroscopy (X-PEEM) : new avenues for the microchemical analysis of liquids, superconductors and minerals /." [S.l.] : [s.n.], 2004. http://library.epfl.ch/theses/?nr=2914.
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Geissler, Eva. "Adenosine A₁ receptors in human sleep regulation studied by electroencephalography (EEG) and positron emission tomography (PET) /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17227.
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Gucker, Pascale-Mariette. "Effects of ecstasy (MDMA) on the brain uptake of [¹¹C](+)McN-5652 studied by positron emission tomography /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13650.
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Weimer, Silke. "Particle emission of traffic and wood combustion and its impact on spatial distributions of submicron particulate matter /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17995.
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Külling, David R. Külling David R. "Influence of feed composition and manure type on trace gas emissions from stored dairy manure /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13872.
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Würth, Barbara. "Emissions of engineered and unintentionally produced nanoparticles to the soil an exposure assessment for Switzerland /." Zurich : ETH Zurich Department of Environmental Sciences, 2007. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=351.
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Trautmann, Thomas. "Environmental investment decisions under regulatory uncertainty : an analysis of corporate responses to regulatory uncertainty in the European Emission Trading scheme /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17291.
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Wenger, Daniela. "Endocrine-disrupting chemicals in the air : investigation of emission sources and ambient concentrations with reporter gene assays and chemical analysis /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18004.
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Mallmann, Ana Paula. "Otimiza??o por simula??o e desenvolvimento de c?lulas solares com emissor posterior formado por pasta de alum?nio e difus?o em forno de esteira." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2011. http://tede2.pucrs.br/tede2/handle/tede/3176.
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Previous issue date: 2011-01-26A produ??o de energia el?trica diretamente a partir da convers?o da energia solar, denominada de energia solar fotovoltaica, ganha destaque pelo baixo impacto ambiental. O principal dispositivo desta tecnologia ? a c?lula solar, sendo o material mais utilizado o sil?cio. As c?lulas solares s?o associadas eletricamente e encapsuladas com a finalidade de formar o m?dulo fotovoltaico. Os objetivos desta tese est?o centrados na otimiza??o, no desenvolvimento e na an?lise de c?lulas solares n+np+ em Si-FV-FZ, tipo n, com emissor posterior p+ formado pela difus?o de pasta de alum?nio em forno de esteira. A otimiza??o por simula??o de uma c?lula solar ? uma etapa importante que precede o desenvolvimento do dispositivo. Nesta etapa, al?m de utilizar o programa computacional PC-1D foi criado um programa na linguagem Visual Basic, denominado MonoCel. Para a simula??o de c?lulas solares com malha de metaliza??o formada por evapora??o em alto v?cuo obteve-se a efici?ncia de 16,8 %, valor 1 % absoluto maior que para o caso da malha de metaliza??o ser formada por serigrafia, que foi de 15,8 %. A partir dos resultados das simula??es, constatou-se que o processo para fabrica??o de c?lulas solares com metaliza??o por serigrafia pode ser mais vi?vel que a evapora??o em alto v?cuo, pois a diferen?a na efici?ncia n?o ? elevada e a t?cnica ? relativamente mais simples. A otimiza??o experimental do processo de textura??o das l?minas de sil?cio resultou na reflet?ncia de 12 %, valor t?pico para uma superf?cie formada por micropir?mides em sil?cio monocristalino. Com a otimiza??o experimental da regi?o de campo retrodifusor frontal de f?sforo, foi obtido um valor de resist?ncia de folha de (36 ? 4) Ω/□ a partir da difus?o de f?sforo com POCl3 em forno convencional. Constatou-se que ap?s a difus?o de f?sforo, ocorreu gettering para temperatura e tempos espec?ficos. Tamb?m se verificou que o tempo de vida dos portadores minorit?rios ao final do processamento das c?lulas solares ? ligeiramente maior que o valor inicial. Foi analisada a influ?ncia da ordem dos passos de queima da pasta de metaliza??o na face frontal e de difus?o/queima da pasta de alum?nio, da passiva??o 27 da superf?cie, do fluxo de ar seco no passo de difus?o/queima da pasta de alum?nio, da temperatura de difus?o/queima da pasta de alum?nio e da velocidade da esteira nas caracter?sticas el?tricas dos dispositivos fabricados. Com o processo de fabrica??o de c?lulas solares com estrutura n+np+ com emissor posterior localizado de alum?nio foram obtidas c?lulas solares com efici?ncia pr?xima a 9,5 %. As melhores c?lulas solares foram processadas na temperatura de difus?o/queima da pasta de alum?nio de 900 ?C e velocidade da esteira de 140 cm/min. A efici?ncia est? limitada pelos baixos valores de VOC e FF alcan?ados. Tamb?m se verificou que a forma??o do emissor posterior localizado resulta em c?lulas solares com maior efici?ncia que o emissor homog?neo.
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Ossowski, Damian Arkadius. "Einfluss unterschiedlicher fettreicher Futtermittel auf Pansenfermentation, Emissionen und Produktequalität bei Wiederkäuern /." [S.l.] : [s.n.], 1999. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12927.
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Daudt, Natalia de Freitas. "Influ?ncia dos par?metros de processo na deposi??o de nitreto de tit?nio por plasma em gaiola cat?dica." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12735.
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Previous issue date: 2012-02-27Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Titanium nitride films were grown on glass using the Cathodic Cage Plasma Deposition technique in order to verify the influence of process parameters in optical and structural properties of the films. The plasma atmosphere used was a mixture of Ar, N2 and H2, setting the Ar and N2 gas flows at 4 and 3 sccm, respectively and H2 gas flow varied from 0, 1 to 2 sccm. The deposition process was monitored by Optical Emission Spectroscopy (OES) to investigate the influence of the active species in plasma. It was observed that increasing the H2 gas flow into the plasma the luminescent intensities associated to the species changed. In this case, the luminescence of N2 (391,4nm) species was not proportional to the increasing of the H2 gas into the reactor. Other parameters investigated were diameter and number of holes in the cage. The analysis by Grazing Incidence X-Ray Diffraction (GIXRD) confirmed that the obtained films are composed by TiN and they may have variations in the nitrogen amount into the crystal and in the crystallite size. The optical microscopy images provided information about the homogeneity of the films. The atomic force microscopy (AFM) results revealed some microstructural characteristics and surface roughness. The thickness was measured by ellipsometry. The optical properties such as transmittance and reflectance (they were measured by spectrophotometry) are very sensitive to changes in the crystal lattice of the material, chemical composition and film thicknesses. Therefore, such properties are appropriate tools for verification of this process control. In general, films obtained at 0 sccm of H2 gas flow present a higher transmittance. It can be attributed to the smaller crystalline size due to a higher amount of nitrogen in the TiN lattice. The films obtained at 1 and 2 sccm of H2 gas flow have a golden appearance and XRD pattern showed peaks characteristics of TiN with higher intensity and smaller FWHM (Full Width at Half Maximum) parameter. It suggests that the hydrogen presence in the plasma makes the films more stoichiometric and becomes it more crystalline. It was observed that with higher number of holes in the lid of the cage, close to the region between the lid and the sample and the smaller diameter of the hole, the deposited film is thicker, which is justified by the most probability of plasma species reach effectively the sample and it promotes the growth of the film
Filmes finos de nitreto de tit?nio foram crescidos sobre vidro utilizando a t?cnica de deposi??o por descarga em gaiola cat?dica a fim de averiguar a influ?ncia das vari?veis de processo nas propriedades ?pticas e estruturais do filme. Como atmosfera do plasma foi utilizada a mistura de gases Ar, N2 e H2, fixando o fluxo de Ar e N2 em 4 e 3 sccm, respectivamente, e usando fluxos de 0, 1 e 2 sccm de H2. O processo de deposi??o foi monitorado por Espectroscopia de Emiss?o ?ptica (OES) para investiga??o das esp?cies ativas no plasma. Observou-se que com o aumento fluxo de H2 as intensidades das esp?cies luminescentes no plasma sofrem altera??es e que a esp?cie N2 (391,4 nm) n?o teve um crescimento proporcional ao fluxo de H2. Outros par?metros investigados foram o di?metro e o n?mero de furos da gaiola. As an?lises de difra??o de raios X com ?ngulo de incid?ncia rasante (GIXRD) comprovaram que os filmes obtidos s?o compostos por TiN, podendo ter varia??es quanto a quantidade de nitrog?nio na rede e o tamanho de cristalito; a microscopia ?ptica forneceu dados sobre a homogeneidade, a partir da microscopia de for?a at?mica (AFM) observou-se algumas caracter?sticas microestruturais do filme e a rugosidade. A espessura foi quantificada atrav?s das an?lises de elipsometria. As propriedades ?pticas como reflet?ncia e transmit?ncia (medidas por espectrofotometria) s?o bastante sens?veis a altera??es na rede cristalina do material, composi??o qu?mica e espessura, sendo, portanto, uma boa ferramenta para verifica??o do controle do processo. De maneira geral, os filmes obtidos com fluxo de 0 sccm de H2 possuem uma maior transmit?ncia atribu?da ao menor cristalinidade decorrente da maior quantidade de nitrog?nio na rede cristalina do TiN. Os filmes obtidos nos fluxos de 1 e 2 sccm de H2 obtiveram um aspecto dourado e o difratograma apresentou picos caracter?sticos do TiN com maior intensidade e menor largura a meia altura, sugerindo que com a presen?a de hidrog?nio na atmosfera do plasma os filmes s?o mais estequiom?tricos e com maior cristalinidade. Quanto ? configura??o da gaiola observou-se que com maior quantidade de furos na tampa, maior a proximidade da tampa com a amostra e menor o di?metro do furo, maior ? a espessura do filme, o que ? justificado pela maior probabilidade das esp?cies do plasma atingirem efetivamente o substrato e promoverem o crescimento do filme
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Dantas, Taisa Cristine de Moura. "Hidr?xidos duplos lamelares de magn?sio e alum?nio modificados com carbonato e p123 para adsor??o de di?xido de carbono." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17685.
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Previous issue date: 2012-08-10Muitos mecanismos provocados pela a??o humana v?m gerando um aumento na queima de combust?veis f?sseis e processos qu?micos (produtos org?nicos, carv?o, madeira, ?leo diesel, gasolina e outros derivados de petr?leo) e, consequentemente, h? um aumento na emiss?o de CO2 na atmosfera. Uma das alternativas para a captura desse poluente ? o processo de adsor??o, o qual pode ajudar na redu??o do CO2. As hidrotalcitas ou hidr?xidos duplos lamelares (HDL s) est?o dentre esses materiais estudados, j? que apresentam alta estabilidade e uma boa porosidade, tornando-se assim um promissor adsorvente de gases poluentes. Os HDL s formam um grupo de argilas do tipo ani?nico que consiste em camadas positivamente carregadas de ?xido de metal (ou hidr?xido de metal) com intercamadas de ?nions. Foi constatado que ?nions que possuem duas cargas negativas, estabilizam muito mais que ?nions monovalentes, sendo o carbonato o mais est?vel dos ?nions divalentes. Neste trabalho, foi proposta uma modifica??o na s?ntese direta atrav?s da co-precipita??o a pH constante utilizando sais de c?tions divalentes (Mg2+) e trivalentes (Al3+) reportados na literatura. Durante a s?ntese dos HDL s retirou-se o carbonato, bem como, utilizou-se um copol?mero como um template para o alargamento das lamelas. As amostras foram caracterizadas utilizando as t?cnicas de DRX, TG/DTG, FTIR, MEV/EDX, MET e adsor??o e dessor??o de N2. Os dados obtidos indicam que a estrutura, mesmo ap?s a modifica??o, apresentou resultados condizentes com os encontrados na literatura. Dentre as v?rias aplica??es dos HDL s foi realizado o estudo da adsor??o do CO2. A capacidade de adsor??o do material foi testada de acordo com o tempo de contato entre o adsorvente e o adsorbato, sendo esperado que os materiais tratados com template apresentassem um maior desempenho
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Houdé, Richard Solène. "Multifissuration de couches d’oxyde thermique sous chargement statique instrumenté par émission acoustique : application aux systèmes Ni/NiO et Zr/ZrO2." Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2617.
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Cette thèse est un travail sur la caractérisation de l’endommagement des couches d’oxydes thermiques et notamment sur les systèmes métal/oxyde Ni/NiO et Zr/ZrO2. Pour étudier cet endommagement un essai de multifissuration sous MEB a été réalisée en couplant une micromachine de traction avec un suivi par émission acoustique à l’intérieur de la chambre du microscope électronique à balayage. Différents essais ont été réalisés afin de paramétrer le système d’émission acoustique pour s’assurer que les signaux enregistrés proviennent bien des éprouvettes de traction testées. Ce travail a permis de disposer d’un essai permettant d’acquérir les salves d’émission acoustique propres aux endommagements des systèmes Ni/NiO et Zr/ZrO2 en conditions in-situ. Grâce à ce développement technique, il a été possible de proposer des scénarii d’endommagement des systèmes Ni/NiO et Zr/ZrO2 pour deux épaisseurs de couches d’oxyde différentes (1 μm et 5 μm environ) en couplant les informations obtenues par les observations MEB (en surface des éprouvettes au cours des essais de traction, et en coupe transverse après rupture des éprouvettes) et l’analyse des signaux acoustiques enregistrés au cours des essais. L’analyse des scénarii d’endommagement a mis en évidence des différences notables entre les deux systèmes étudiés, mais également des différences au sein d’un même système selon les conditions d’oxydation utilisées pour obtenir les épaisseurs de couches désirées. Au-delà de permettre des propositions de scenarii d’endommagement, l’analyse des salves d’émission acoustique a permis de qualifier des signatures différentes pour les propagations des fissures en mode I et en mode IIThis thesis is a work on the characterization of the damage of thermal oxide scales and in particular on the metal/oxide systems Ni/NiO and Zr/ZrO2. To study this damage, a multi-cracking test under SEM was carried out by coupling a traction micromachine with monitoring by acoustic emission inside the chamber of the scanning electron microscope. Various tests were carried out in order to configure the acoustic emission system to ensure that the recorded signals indeed come from the tensile specimens tested. This work made it possible to have a test making it possible to acquire the acoustic emission bursts specific to damage to Ni/NiO and Zr/ZrO2 systems under in-situ conditions. Thanks to this technical development, it was possible to propose damage scenarios for Ni/NiO and Zr/ZrO2 systems for two different oxide scale thicknesses (1 μm and 5 μm approximately) by coupling the information obtained by the SEM observations (on the surface of the specimens during tensile tests, and in cross section after rupture of the specimens) and analysis of the acoustic signals recorded during the tests. The analysis of the damage scenarios revealed notable differences between the two systems studied, but also differences within the same system depending on the oxidation conditions used to obtain the desired scale thicknesses. Beyond allowing proposals for damage scenarios, the analysis of the acoustic emission bursts made it possible to qualify different signatures for the propagation of cracks in mode I and in mode II
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Kirchen, Patrick. "Steady-state and transient diesel soot emissions : development of a mean value soot model and exhaust-stream and in-cylinder measurements /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18088.
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Essassi, Khawla. "Développement et caractérisation statique et dynamique d'un composite sandwich à âme auxétique et à constituants naturels." Thesis, Le Mans, 2020. http://cyberdoc-int.univ-lemans.fr/Theses/2020/2020LEMA1025.pdf.
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Durant ces dernières années, les matériaux composites bio sourcés sont utilisés dans différents secteurs industriels suite à leurs intérêts environnementaux. L’utilisation d’une matrice biologique renforcée par des fibres végétales permet d’améliorer non seulement la protection environnementale mais aussi les performances mécaniques. D’autre part, les structures auxétiques ont émergées pour leurs hautes propriétés spécifiques performantes et surtout leurs grandes capacités d’absorption énergétique. Dans ce cadre, cette étude propose l’élaboration d’un matériau composite sandwich à âme auxétique en nid d’abeilles ré-entrantes et à constituant purement naturel. Cette structure a été élaborée par la méthode de fabrication additive. D’abord, le comportement statique en traction des peaux est analysé. Les caractéristiques élastiques des éprouvettes imprimées suivant différentes directions sont déterminées. Par la suite, les propriétés mécaniques des âmes auxétiques en traction, en compression ainsi que celles des sandwichs en flexion et indentation ont été étudiées. Une analyse des mécanismes d’endommagement au cours des essais d’indentation est effectuée en utilisant la technique de l’émission acoustique. Ensuite, des essais expérimentaux et des modèles analytiques (et éléments finis) ont été menés pour déterminer le comportement en fatigue des sandwichs. Enfin, une étude du comportement vibratoire de la peau, d’âmes et des sandwichs est réalisée suite à une étude expérimentale et numérique par éléments finis. L’effet de chaque composant dans l’amortissement global est discutéIn recent years, bio-based composite materials have been used in different industrial sectors due to their environmental interests. The use of a biological matrix reinforced with vegetable fibers makes it possible to improve not only environmental protection but also mechanical performance. On the other hand, auxetic structures have emerged as a result of their high specific properties and especially their great energy absorption capacities. In this context, this study proposes to develop a composite sandwich material with a re-entrant honeycomb core and a purely natural constituent. In order to build this structure, the additive manufacturing method was used. First, the static tensile behavior of the skins is analyzed. The elastic characteristics of the printed specimens in different directions are determined. Subsequently, the mechanical properties of auxetic cores in tension and in compression as well as those of sandwiches in bending and indentation were developed. An analysis of damage mechanisms during indentation tests is performed using the acoustic emission technique. Then, experimental tests and analytical models were carried out to determine the fatigue behavior of the sandwiches. Finally, a study of the vibration behavior of the skin, cores and sandwiches is carried out using an experimental and numerical study by finite element. The contribution of each component in the global damping properties is discussed
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Soares, Paula Fernanda Chaves. "Varia??o de atributos e din?mica de carbono e nitrog?nio em Organossolos em fun??o de uso e manejo agr?cola no Rio de Janeiro." Universidade Federal Rural do Rio de Janeiro, 2011. https://tede.ufrrj.br/jspui/handle/jspui/1226.
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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPQ
The Histosols are characterized by high organic content, distinguishing this class from others in the Brazilian System of Soil Clasification. Because of this characteristic they are more fragile in face of agricultural use and management than mineral soils. The agricultural drainage is the most important practice that changes soil properties and it is the cause of subsidence, which impacts on other attributes. On the other hand, Histosols are an important natural reservoir of carbon in the soil. However, there are few studies on the dynamics of carbon and nitrogen and potential contribution of greenhouse gases as a result of agricultural usage. The study aims to identify changes in edaphic attributes and dynamics of carbon and nitrogen of Histosols in a floodplain environment in State of Rio de Janeiro, according to types of land use and agricultural management. Three areas with different managements were selected. Two areas are located in Macae municipality, under pasture and annual crop rotation, and the third in Santa Cruz, in Rio de Janeiro city, cultivated with cassava (Manihot esculenta). They were evaluated: chemical and physical attributes, including aggregate stability and specific attributes of Histosols; content soil organic matter (SOM), carbon in the fractions - humin (HUM-C), humic acid (HAF-C) and fulvic acid (C-FAF); stocks of C and N; and flux of gases CO2 and N2O from soil to atmosphere. In general, the area cultivated with cassava had the highest values for the exchangeable cations at all depths; in the first sampling the H value varied from 32.1 to 33.2 cmolc kg-1, and Ca from 20.4 to 15.7 cmolc kg-1. In the second sampling K and P (5.16 to 4.36 cmol c kg-1, and 4 mg kg-1, respectively) were highest in the cassava crop area. The levels of (SOM) were highest in the pasture for the two sampling periods, with values ranging from 306.3 to 249.0 g kg-1 (WB method) and 297.8 to 278,5 g kg-1 (oven method) for the first sampling, and from 303.2 to 153.9 g kg-1 (WB) and 322.9 to 176.1 g kg-1 (oven) in the second period, indicating that this usage is less aggressive to the soil. The physical properties of Histosols may be used to indicate degree of subsidence. Thus, the high values of particle density and bulk density (1.9 and 0.8 Mg m-3); the total volume of pores that ranged from 54 to 60% with the lowest values in the two samplings; and minimum residue and mineral material highest than other usages (0.49 to 0.44 cm and 85.1 cm-1 to 80.7%, respectively) in the cassava area point to the high subsidence ot these soil. As for SOM chemical fractionation, the C_HUM indicated that this fraction had highest expression in all areas. In the second sampling the cassava area showed the lowest values of C-HUM (79.05 to 76.27 g kg-1), followed by C_FAH (44.56 to 40.05 g kg-1) and C_FAF (20.37 to 14.36 g kg-1). The stocks of C and N were highest in the pasture area, indicating better preservation of SOM, with values from 72.93 to 117.12 mg kg-1 for C and from 8.35 to 2,67 mg kg-1 for N. The values of CO2-C flux were within the range of variation proposed by the IPCC, where the highest emission value corresponded to 0.09 Mg CO2 ha-1 day-1 in the pasture area. The values of N2O-N flux were lower than the emission rate proposed by the IPCC, with the highest value around 270 g N2O-N m-2 day-1 in the area with beans. In general, the area with pasture management stood up as management that caused the least damage to the Histosols properties, among the land use evaluated.
Os Organossolos caracterizam-se pelo alto teor de material org?nico, que distingue essa classe das demais no Sistema Brasileiro de Classifica??o de Solo. Ainda, por essa caracter?stica s?o solos mais fr?geis diante do uso e manejo agr?cola que solos com dom?nio de minerais. Dentre as pr?ticas que mais alteram as propriedades ed?ficas, a drenagem ? a mais importante e ? respons?vel pelo processo de subsid?ncia com impactos em v?rios atributos. Por outro lado, os Organossolos s?o importante reservat?rio natural de carbono no solo. Ainda assim s?o poucos os estudos sobre a din?mica de carbono e nitrog?nio e o potencial de contribui??o com gases de efeito estufa diante do manejo agr?cola. O estudo visa identificar altera??es nos atributos ed?ficos e na din?mica de carbono e nitrog?nio de Organossolos em ambiente de v?rzea no Estado do Rio de Janeiro, em fun??o de tipos de uso e manejo agr?cola. Foram selecionadas tr?s ?reas com manejos distintos. Duas ?reas localizam-se em Maca?, com pastagem e rota??o de culturas anuais, e a terceira em Santa Cruz, no Rio de Janeiro, com mandioca (Manihot esculenta). Foram avaliados: atributos qu?micos e f?sicos, incluindo estabilidade de agregados e atributos espec?ficos de Organossolos; teores de mat?ria org?nica do solo (MOS) e o teor de C nas fra??es humina (C-HUM), ?cido h?mico (C-FAH) e ?cido f?lvico (C-FAF); estoques de C e N; e fluxos dos gases CO2 e N2O do solo para a atmosfera. Em geral, a ?rea com mandioca apresentou os maiores valores para o complexo sortivo em todas as profundidades; na primeira coleta o H variou de 32,1 a 33,2 cmolc kg-1, e o Ca entre 20,4 e 15,7 cmolc kg-1. Na segunda coleta destacam-se os valores de K e P (5,16 e 4,36 cmolc kg-1 e 4 mg kg-1, respectivamente) tamb?m maiores na ?rea com mandioca. A MOS mostrou maior teor na ?rea de pastagem para as duas coletas, com valores variando entre 306,3 a 249,0 g kg-1 (m?todo WB) e 297,8 a 278,5 g kg-1 (m?todo da mufla) na primeira coleta, e para a segunda coleta de 303,2 a 153,9 g kg-1 (WB) e 322,9 a 176,1 g kg-1 (mufla), o que indica que esse manejo ? menos agressivo ao solo. As propriedades f?sicas dos Organossolos podem indicar o seu grau de subsid?ncia. Assim, os valores altos de densidade da part?cula e densidade do solo (em torno de 1,9 e 0,8 Mg m-3) mais o volume total de poros, que variou de 54 a 60% sendo os menores nas duas coletas, e o res?duo m?nimo e material mineral com valores maiores (0,49 a 0,44 cm cm-1 e 85,1 a 80,7%, respectivamente) indicam para a ?rea de mandioca maior grau de subsid?ncia. No fracionamento qu?mico da MOS o C_HUM indicou que essa fra??o teve maior express?o em todos as ?reas. Na segunda coleta a ?rea de mandioca apresentou os menores valores de CHUM (79,05 a 76,27 g kg-1) seguidos de C_FAH (44,56 a 40,05 g kg-1) e C_FAF (20,37 a 14,36 g kg-1). Os estoques de carbono e nitrog?nio foram mais altos no solo sob pastagem, indicando melhor conserva??o da MOS, com valores entre 117,12 e 72,93 Mg kg-1 para C e 8,35 e 2,67 Mg kg-1 para N. Os valores de fluxo de C-CO2 estiveram dentro da faixa de varia??o proposta pelo IPCC, em que o maior valor de emiss?o correspondeu a 0,09 Mg CO2 ha-1 dia-1 na ?rea de pastagem. Os valores de N-N2O foram menores que a taxa de emiss?o proposta pelo IPCC, com o valor mais elevado em torno de 270 ?g N-N2O m-2 dia-1 e na ?rea com feij?o. Em geral, a pastagem se destacou como o manejo que causou menor altera??o nas propriedades dos Organossolos, dentre as formas de uso da terra avaliadas.
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Alves, Yony Brugnolo. "Uma abordagem institucional do mecanismo de desenvolvimento limpo: o caso da suinocultura da pequena propriedade rural." Universidade Estadual do Oeste do Parana, 2009. http://tede.unioeste.br:8080/tede/handle/tede/2256.
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Previous issue date: 2009-07-21The intensification of the related problems to the greenhouse have in recent decades called the attention and committed efforts of the civil society to the treatment of this serious context resulting from the man acts. From this environmental concern, social and development, it was ratified in February 2005 the Kyoto Protocol, whose premise is the creation of trade market mechanisms that allow industrialized countries a significant reduction of pollutants gases emissions in nature. Under the subjects covered by the Kyoto Protocol, it is pointed out the Clean Development Mechanism (CDM) and the establishment of a market of carbon credits. In this scenario, developing countries can participate in this market selling carbon credits to countries which have outstanding responsibility in the emission of harmful gases to the environment. However, the institution of the carbon credits market and the establishment of the CDM require an institutional framework to rule, according to the language adopted by the New Institutional Economy, the "rules of the game . Opportunely, this research investigates the institutional aspects of this scenario and the conditions to rule the CDM projects in Brazil, highlighted the main bureaucratic and sometimes, technical barriers, that hinder or even prevent the entry of Brazilian companies in the international carbon credit market. The discussions, analysis and findings presented address the institutional constraints and the estimates about the gains that can be obtained from the CDM, having as a case study a swine farm located in Toledo, a city located in west of Paraná - Brazil. The found results indicate that, partially, the institutional environment of the carbon credits market is not sufficiently clear to the extent of encouraging the entry of Brazilian firms in this context, and the constant changes that occur therein confuse the economic agents. Furthermore, it is observed that the execution of a CDM can bring gains of technical, economic, social and especially environmental order.
A intensificação de problemas relacionados ao Efeito Estufa tem, nas últimas décadas, chamado a atenção e mobilizado esforços da sociedade civil e organizada no mundo todo para o tratamento desse grave contexto resultante da ação do homem. Essa preocupação de abrangência ambiental, social e de desenvolvimento, levou em fevereiro de 2005, à ratificação do Protocolo de Quioto, cuja premissa é a criação de mecanismos de mercado que viabilizem aos países industrializados uma relevante redução na emissão de gases poluentes na natureza. Dentre as matérias contempladas pelo Protocolo destaca-se o Mecanismo de Desenvolvimento Limpo (MDL) e a instituição de um mercado de créditos de carbono. Nesse cenário, os países em desenvolvimento podem participar vendendo créditos de carbono aos países que têm destacada responsabilidade na emissão de gases nocivos ao meio ambiente. Todavia, a instituição do mercado de créditos de carbono e a instauração do MDL exigem um arcabouço institucional para reger, conforme a linguagem adotada pela Nova Economia Institucional, as regras do jogo . Oportunamente, a presente pesquisa investiga os aspectos institucionais desse cenário e as condições que regulamentam os projetos de MDL no Brasil, apontado as principais barreiras burocráticas e por vezes, técnicas, que dificultam ou até mesmo inviabilizam o ingresso das empresas brasileiras no mercado internacional dos créditos de carbono. As discussões, análises e constatações apresentadas abordam as limitações institucionais e as estimativas acerca dos ganhos que podem ser obtidos a partir do MDL, tendo como estudo de caso uma granja suína situada na cidade de Toledo, região oeste do Paraná Brasil. Os resultados encontrados apontam que, em partes, o ambiente institucional do mercado de créditos de carbono não está suficientemente claro a ponto de incentivar o ingresso das empresas brasileiras nesse contexto, e as constantes modificações que nele ocorrem confundem os agentes econômicos. Por outro lado, é observado que a montagem e execução de um MDL podem trazer ganhos de ordem técnica, econômica, social e principalmente ambiental.
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Unnikrishnan, Anagha K. "Design, Synthesis and Optical Characterization of 1,8-Naphthalimide based D-pi-A System." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5095.
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Design, Synthesis and Optical Characterization of 1,8-Naphthalimide based D-pi-A System
Luminescent materials find a lot of application in the field of OLEDs and bio-medical applications [1-2]. Our group has recently developed a series of 1,8-naphthilimide (NPI) based Donor-Acceptor (D-A) system [2], and we were able to fine-tune optical properties of 1,8-naphthilimide by changing donor strength judiciously. Furthermore, the PL features of 1,8-naphthilimide derivatives were sensitive to triplet oxygen, and these molecules were explored for differential imaging of hypoxia and normoxia live cancer cells. In the present study, we aim to extend the scope of available naphthalimide dyes by extending the system's conjugation by placing pi-spacer to obtain emission in near IR and utilize them for bio-imaging. In our earlier reports, the cyclic amine donors were directly connected with NPI acceptor through nitrogen on the amine moieties. In this study, we intended to connect the donor moiety via the carbon center of the amine donor moiety through a π-conjugated spacer with anticipation that the conjugated spacer may enhance the electronic conjugation length and reduce the bandgap; consequently, NIR emission may be realized. Accordingly, we designed two D-pi-A and D-pi-A-pi-D systems where donor phenothiazine is linked to accepter NPI through the vinyl pacer. The newly synthesized molecules show emission in the NIR region and the results are summerised in this thesis.
1. Salehi, A.; Fu, X.; Shin, D.; So, F. Adv. Funct. Mater 2019, 1808803, 1–21.
2. Liu, J.; Guo, X.; Hu, R.; Liu, X.; Wang, S.; Li, S.; Li, Y.; Yang, G.. Anal. Chem.2016, 88 , 1052–1057.
3. Jena, S.; Dhanalakshmi, P.; Bano, G.; Thilagar, P. J. Phys. Chem. B 2020, 124, 5393–5406.
4. Monici, M. Biotechnology annual review, 2005, 11, 227-256.
5. Pansare, V.J.; Hejazi, S.; Faenza, W. J.; Prud’homme, R. K. Chemistry of materials, 2012, 24, 812-827.
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Chen, I. Jen, and 陳以仁. "A new series of NIR emissive Pt(II) complexes." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/30517891188506276104.
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"Analisys and control of pollutans emissions from a boiler operating with fuel oil." Tese, MAXWELL, 2003. http://www.maxwell.lambda.ele.puc-rio.br/cgi-bin/db2www/PRG_0991.D2W/SHOW?Cont=4433:pt&Mat=&Sys=&Nr=&Fun=&CdLinPrg=pt.
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