Orientador: Silvana Moreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-22T10:28:59Z (GMT). No. of bitstreams: 1 Broleze_SilvanaTurolla_M.pdf: 3879465 bytes, checksum: 55a0753c8198f927cfe15629d6203167 (MD5) Previous issue date: 2013 / Resumo: O aumento da produção de lodo de esgoto é decorrente do crescimento do volume de esgoto tratado e do número de estações de tratamento de esgotos no Brasil e, tem exigido a busca de alternativas para a sua disposição final. Dentre as várias alternativas de disposição, a utilização agrícola e a compostagem são viáveis, uma vez que o lodo é rico em matéria orgânica, macro e micronutrientes necessários à fertilidade dos solos. Porém, devido aos lançamentos clandestinos e despejos industriais nas redes públicas de coleta de esgoto, pode haver a presença de elementos que causam danos à saúde humana e ambiental, como Pb, Hg, Cd, As, Cr e Se. Este trabalho avaliou as substâncias inorgânicas potencialmente tóxicas no lodo, previamente desaguado, das ETE Camanducaia em Jaguariúna; Vila Flora em Sumaré; Praia Azul e Carioba em Americana; Samambaia, Anhumas, Santa Mônica, Piçarrão e Barão Geraldo em Campinas, SP, por meio de SR-TXRF. Os lodos das estações de tratamento de esgoto da Região Metropolitana de Campinas atendem a Legislação CONAMA 375/06, com exceção do lodo da ETE Santa Mônica que, durante o período seco, excedeu os limites para o Cu (1500 mg kg-1) e Ni (420 mg kg-1). De acordo com a IN n° 27/06 do MAPA, os lodos das estações ultrapassam em, pelo menos, uma coleta o limite para os elementos Ni (70 mg kg-1), e Cr (200 mg kg-1). Durante o período seco, ocorreu uma maior concentração dos elementos, em relação ao período chuvoso. As amostras de lodo das ETE Vila Flora e Praia Azul, durante o período chuvoso, comparadas com um padrão certificado NIST 2781, apresentaram características de lodo doméstico. Para que o lodo de parte da RMC possa ter destinação agrícola, de acordo com as legislações ambientais vigentes no país, é necessário que haja uma redução do Ni, Cr e Cu. Uma das alternativas seria uma maior fiscalização nas fontes geradoras, de modo a melhorar a qualidade do afluente das estações, adequando o lodo de esgoto às legislações brasileiras / Abstract: The increased production of sewage sludge is due to the growth in the volume of sewage treated and the number of sewage treatment plants in Brazil and has demanded the search for alternatives for their final disposal. Among the various alternatives available, agricultural use and composting are viable, since the sludge is rich in organic matter, macro and micronutrients necessary for soil fertility. However, due to illegal releases and industrial waste at public sewage collection, there may be the presence of elements that cause damage to human and environmental health, as Pb, Hg, Cd, As, Cr and Se. This study evaluated the potentially toxic inorganic substances in the sludge, dewatered previously, the WWTP Camanducaia in Jaguariúna; Villa Flora in Sumaré; Praia Azul and Carioba in Americana; Samambaia, Anhumas, Santa Monica, and Piçarrão Barão Geraldo Campinas, SP, using SR-TXRF. The sludge from wastewater treatment plants in the metropolitan region of Campinas (MRC) attend Legislation CONAMA 375/06, except sewage sludge from the WWTP Santa Monica that, during the dry period, exceeded the limits for Cu (1500 mg kg-1) and Ni (420 mg kg-1). According to the Normative Ruling (IN) nº. 27/06 MAPA, the sludge from the stations exceeded in at least one collection limit for the elements Ni (70 mg kg-1), and Cr (200 mg kg-1). During the dry season, there was a higher concentration of elements in relation to the rainy season. The sludge samples of the WWTP Vila Flora and Praia Azul during the rainy period, compared with a standard certificate NIST 2781, showed characteristics of domestic sewage. For the sludge part of MRC may have agricultural destination, according to the environmental laws in force in the country, there must be a reduction of Ni, Cr and Cu. One alternative would be greater oversight in generating sources in order to improve the quality of tributary stations, adjusting the sewage sludge to Brazilian laws / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Complex concentrated alloys (CCAs) offer the unique ability to tune composition and microstructure to achieve a wide range of mechanical performance. Recently, the development of metastable CCAs has led to the creation of transformation-induced plasticity (TRIP) CCAs. Similar to TRIP steels, TRIP CCAs are more effective at absorbing high strain rate loads when TRIP is activated during the loading process. The objective of our study is to investigate the effect of copper on the critical pressure for activating TRIP and the high pressure stability of a Fe(40-X)Mn20Cr15Co20Si5CuX TRIP CCA, where x varies from 0 to 3 at.% Cu. To achieve this goal, diamond anvil cell testing during in-situ synchrotron radiation X-ray diffraction was performed using both a monochromatic wide angle X-ray scattering (WAXS) beam and, for the first time ever, a polychromatic Laue diffraction beam on a CCA. Laue diffraction allows for real-time phase evolution tracking of the γ-fcc → ε-hcp transformation in a high pressure environment. Based on the results, a new method for processing and preparation of high pressure samples without changing the microstructure of sample was developed. This new method can be used to prepare any CCA samples for high pressure testing.

This work addresses the growth of ultrathin magnetite (Fe3O4) and cobalt ferrite (CoFe2O4) films and their thorough structural, electronic, and magnetic characterization. In a first step, ultrathin Fe3O4 films are grown on SrTiO3(001) substrates by reactive molecular beam epitaxy (RMBE) and the substrate-induced anomalous strain behavior of the films is investigated by complementary high-resolution transmission electron microscopy (HRTEM) and (grazing incidence) X-ray diffraction [(GI)XRD] measurements. Next, an additional CoO film is deposited on similar Fe3O4/SrTiO3(001) heterostructures to demonstrate an alternative route for the synthesis of cobalt ferrite films through the thermally mediated interdiffusion of both oxide films. The evolution from the initial bilayer stacks to completely reacted cobalt ferrite films is extensively monitored by soft and hard X-ray photoelectron spectroscopy (soft XPS and HAXPES) and (GI)XRD. Complete intermixing and formation of single cobalt ferrite films is confirmed by angular-resolved HAXPES (AR-HAXPES) and X-ray reflectivity (XRR). The study of the cationic distribution resulting from this novel synthesis technique and its effects on the magnetic properties of the cobalt ferrite films is the subject of the subsequent part. Here, X-ray magnetic circular dichroism (XMCD) and superconducting quantum interference device (SQUID) magnetometry serve as key investigation techniques, which are further complemented by AR-HAXPES and atomic force microscopy (AFM) measurements. In a final step, highly crystalline cobalt ferrite films with different cationic stoichiometries are grown on MgO substrates using RMBE while their growth behavior is captured in real-time using operando XRD. Further structural characterization of the films is carried out by low-energy electron diffraction and XRR, whereas HAXPES and SQUID provide fundamental information on the electronic, chemical, and magnetic properties of the films.

京都大学 / 新制・課程博士 / 博士(人間・環境学) / 甲第23287号 / 人博第1002号 / 新制||人||236(附属図書館) / 2020||人博||1002(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 内本 喜晴, 教授 田部 勢津久, 准教授 戸﨑 充男 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

Les lasers à électrons libres (LEL) X sont aujourd'hui des sources lumineuses cohérentes et intenses utilisées pour des investigations multidisciplinaires de la matière. Un nouveau schéma d'accélération, l'accélérateur laser plasma (LPA), est maintenant capable de produire une accélération de quelques GeV/cm, bien supérieure à celle des linacs radiofréquence. Ce travail de thèse a été mené dans le cadre des programmes de R&D du projet LUNEX5 (laser à électrons libres utilisant un nouvel accélérateur pour l’exploitation du rayonnement X de 5e génération) de démonstrateur LEL avancé et compact avec applications utilisatrices pilotes. Il comprend un linac supraconducteur de 400 MeV de haute cadence (10 kHz) pour l’étude de schémas LEL avancés, et LPA pour sa qualification par une application LEL. La ligne LEL utilise une configuration d’injection avancée dans la plage spectrale 40-4 nm par génération d’harmoniques à gain élevé (HGHG) et schéma d’écho (EEHG) avec des onduleurs compacts cryogéniques à champ élevé de courte période courte. L'étude de solutions adaptées aux applications LEL compactes et avancées est donc examinée. Un premier aspect concerne la réduction du milieu de gain du LEL (électrons dans l'onduleur), le raccourcissement de la période se faisant au détriment du champ magnétique. Les onduleurs cryogéniques compacts à base d'aimants permanents cryogéniques (CPMU), dans lesquels les performances de l'aimant sont améliorées à la température cryogénique sont étudiés. Une deuxième partie du travail développée dans le cadre l’expérience de R&D COXINEL visant à démontrer l’amplification LEL à l’aide d’un LPA. La ligne permet de manipuler les propriétés des faisceaux d’électrons produits (dispersion en énergie, divergence, variation de pointé) avant d’être utilisées pour des applications de sources lumineuses. Le faisceau d'électrons généré est très divergent et nécessite une bonne manipulation juste après la source avec des quadrupôles forts placés immédiatement après la génération d'électrons. Ainsi, des quadrupôles innovants à aimants permanents de gradient élevé réglable appelés «QUAPEVA», sont développés. Ils sont optimisés avec le code RADIA et caractérisées avec trois mesures magnétiques. Un gradient de 200 T/m avec une variabilité de 50 % est obtenu tout en maintenant une excursion du centre magnétique réduite à ± 10 µm, qui a permis un alignement par compensation de pointé du faisceau dans COXINEL grâce au centre magnétique variable des systèmes, avec un faisceau bien focalisé sans dispersion. Les QUAPEVA constituent des systèmes originaux dans le paysage des quadrupôles à de gradient élevé et variable développés jusqu'à présent. Une troisième partie des travaux concerne l’observation du rayonnement d’onduleur monochromatique ajustable sur la ligne COXINEL. Le faisceau d'électrons d'énergie de 170 MeV est transporté et focalisé dans un CPMU de 2 m et de période de 18 mm émettant à 200 nm. Le flux spectral est caractérisé à l'aide d'un spectromètre UV et le flux angulaire mesuré par une caméra CCD. La longueur d'onde est accordée avec l’entrefer. Les distributions spatio-spectrales mesurées en forme de lune du rayonnement de l'onduleur sont bien reproduites par les simulations de rayonnement utilisant les distributions d’électrons mesurées et transportées le long de la ligne. Elles permettent aussi de renseigner sur la qualité du faisceau d’électrons, de son transport et d'en estimer les paramètres tels que la dispersion en énergie et la divergence. Le dernier aspect du travail est lié à la comparaison entre la génération des harmoniques en gain élevé et le schéma d’écho, dans le cadre de ma participation à une expérience réalisée à FERMI @ ELETTRA. Nous avons pu démontrer un LEL de type écho à 5,9 nm, avec spectres plus étroits et une meilleure reproductibilité que le schéma HGHG à deux étages. Cette thèse constitue un pas en avant vers les lasers à électrons libres compacts et avancés. / X-ray Free Electron Lasers (FEL) are nowadays unique intense coherent fs light sources used for multi-disciplinary investigations of matter. A new acceleration scheme such as Laser Plasma Accelerator (LPA) is now capable of producing an accelerating gradient of few GeV/cm far superior to that of conventional RF linacs. This PhD work has been conducted in the framework of R&D programs of the LUNEX5 (free electron Laser Using a New accelerator for the Exploitation of X-ray radiation of 5th generation) project of advanced and compact Free Electron laser demonstrator with pilot user applications. It comprises a 400 MeV superconducting linac for studies of advanced FEL schemes, high repetition rate operation (10 kHz), multi-FEL lines, a Laser Wake Field Accelerator (LWFA) for its qualification by a FEL application. The FEL lines comports enables advanced seeding in the 40-4 nm spectral range using high gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) with compact short period high field cryogenic undulators. The study of compact devices suitable for compact FEL applications is thus examined. One first aspect concerns the reduction of the Free Electron Laser gain medium (electrons in undulator) where shortening of the period is on the expense of the magnetic field leading to an intensity reduction at high harmonics. Compact cryogenic permanent magnet based undulators (CPMUs), where the magnet performance is increased at cryogenic temperature making them suitable for compact applications, are studied. Three CPMUs of period 18 mm have been built: two are installed at SOLEIL storage ring and one at COXINEL experiment. A second part of the work is developed in the frame of the R&D programs is the COXINEL experiment with an aim at demonstrating FEL amplification using an LPA source. The line enables to manipulate the properties of the produced electron beams (as energy spread, divergence, induced dispersion due) before being used for light source applications. The electron beam generated is highly divergent and requires a good handling at an early stage with strong quadrupoles, to be installed immediately after the electron generation source. Hence, the development of the so-called QUAPEVAs, innovative permanent magnet quadrupoles with high tunable gradient, is presented. The QUAPEVAs are optimized with RADIA code and characterized with three magnetic measurements. High tunable gradient is achieved while maintaining a rather good magnetic center excursion that allowed for beam pointing alignment compensation at COXINEL, where the beam is well-focused with zero dispersion at any location along the line. The QUAPEVAs constitute original systems in the landscape of variable high gradient quadrupoles developed so far. A third part of the work concerns the observation of tunable monochromatic undulator radiation on the COXINEL line. The electron beam of energy of 170 MeV is transported and focused in a 2-m long CPMU with a period of 18 mm emitting radiation light at 200 nm. The spectral flux is characterized using a UV spectrometer and the angular flux is captured by a CCD camera. The wavelength is tuned with the undulator gap variation. The spatio-spectral moon shape type pattern of the undulator radiation provided an insight on the electron beam quality and its transport enabling the estimation of the electron beam parameters such as energy spread and divergence. The final aspect of the work is related to the comparison between the echo and high gain harmonic generation, in the frame of my participation to an experiment carried out at FERMI@ELETTRA. At FERMI, we have demonstrated a high gain lasing using EEHG at a wavelength of 5.9 nm where it showed a narrower spectra and better reproducibility compared to a two-stage HGHG. This PhD work constitutes a step forward towards advanced compact Free Electron Lasers.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18067号 / 理博第3945号 / 新制||理||1568(附属図書館) / 30925 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 瀬戸 誠, 教授 鶴 剛, 教授 大久保 嘉高 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(人間・環境学) / 甲第24710号 / 人博第1083号 / 新制||人||253(附属図書館) / 2022||人博||1083(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 内本 喜晴, 教授 田部 勢津久, 教授 吉田 鉄平, 教授 雨澤 浩史 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

Recent developments of X-ray photoelectron spectroscopy using excitation energies different from the usual lab-sources Mg Kα and Al Kα, thus covering larger and different kinetic energy ranges, require more flexible approaches for determining the transmission function than the well-established ones using reference spectra. Therefore, the approach using quantified peak areas (QPA) was refined allowing a more precise estimation of the transmission function. This refinement was tested by comparing the results obtained with the new version with former calculations. Furthermore, the obtained transmission function was validated by comparing the results with a transmission function using the reference spectrum of polyethylene. Additionally, an ionic liquid was used as reference for estimating the transmission function at the energyresolved HE-SGM beamline at BESSY II. Comparison between the measured and stoichiometric composition shows that a transmission function was determined, which allows a reasonable quantification.

Li-O2 batteries have been attracting increasing attention and R&D efforts as promising power sources for electric vehicles (EVs) due to their significantly higher theoretical energy densities compared to conventional Li-ion batteries. The research presented in this thesis covers the investigation of factors influencing the decomposition of Li2O2, the development of highly active electrocatalysts, and the design of low-cost and easy-operation binder-free O2 electrodes for Li-O2 batteries. Being the main technique, SR-PXD was used both as a continuous light source to advance the electrochemical decomposition of Li2O2 under the X-ray illumination and an operando tool that allowed us to probe the degradation of Li2O2. Since XRD was intensively used in my thesis work, the effect of X-ray irradiation on the stability of Li2O2 was studied. The accelerating effect of X-rays on the electrochemical decomposition of Li2O2 was, for the first time, explored. The electrochemical decomposition rate of Li2O2 was proportional to the X-ray intensity used. It is proposed that the decomposition might involve a three-step reaction with [Li2O2]x+ and Li2-xO2* as intermediates, which followed pseudo-zero-order kinetics. Then, three electrocatalysts (Pt/MNT, Ru/MNT and Li2C8H2O6) were developed, which exhibited good electrocatalytic performances during the OER. Their activities were evaluated by following the Li2O2 decomposition in electrodes during the charging processes. In addition, the time-resolved OER kinetics for the electrocatalyst-containing Li-O2 cells charged galvanostatically and potentiostatically was systematically investigated using operando SR-PXD. It was found that a small amount of Pt or Ru decoration on the MNTs enhanced the OER efficiency in a Li-O2 cell. The Li2O2 decomposition of an electrode with 5 wt% Pt/MNT, 2 wt% Ru/MNT or Li2C8H2O6 in a Li-O2 cell followed pseudo-zero-order kinetics. Finally, a novel binder-free NCPE for Li-O2 batteries was presented. It displayed a bird’s nest microstructure, which could provide the self-standing electrode with considerable mechanic durability, fast O2 diffusion and enough space for the discharge product deposition. The NCPE contained N-containing functional groups, which may promote the electrochemical reactions.

<p>This thesis contains two parts. The first part concerns the research work on free molecules using synchrotron-radiation-related techniques. Auger electron spectra of two free open-shell molecules, O₂ and NO, were studied experimentally and theoretically. Photoionization experimental technique with tunable synchrotron radiation source was used to induce core-level electron ionization and obtain the <i>KVV</i> normal Auger electron spectra. A quantitative assignment of O₂ normal Auger spectrum was obtained by applying <i>ab initio</i> CI calculations and LVI Auger line shape simulations including the bond length dependence of Auger transition rates. The photon energy dependence of normal Auger electron spectra was focused on with photon energies in the vicinities of core-ionization threshold energies. Consequently, the MAPCI (Molecular Auger Post Collision Interaction) theory was developed. Taking the near-threshold O₂ normal Auger spectrum as an example, the two extreme cases of MAPCI effect, “atomic-like PCI” and “molecular PCI”, were discovered and discussed. The effect of shape resonance on near-threshold molecular normal Auger spectrum was discussed taking NO near threshold normal Auger spectra as example.</p><p>The second part deals with research work on the chemisorption of small epoxy organic molecules, ethylene oxide, methyl oxirane, on Si (100) surfaces. Synchrotron radiation related techniques, UPS, XPS and NEXAFS, were applied. Based on the valence photoemission spectra, C 1<i>s</i> and Si 2<i>p</i> XPS spectra, the epoxy ring opening reactions of these molecules in chemisorption process were proved. Further tentative search for the surface-adsorbate CDAD effect was performed, and no evident circular dichroism was confirmed.</p>