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O monitoramento da qualidade das águas subterrâneasno Estado de São Paulo realizado pela agência ambiental estadual (CETESB),tem identificado problemas regionais que vem chamando a atenção dos órgãos gestores de meio ambiente, recursos hídricos e concessionárias de água. Dentre os problemas, teores anômalos de bário tem sido identificados com frequência em poços de abastecimento públicos, localizados principalmente no Sistema Aquífero Bauru (SAB), entretanto, com origem desconhecida pela CETESB. O poço de abastecimento do município de Gália, área alvo deste estudo, se encontra entre os poços de abastecimento que captamáguas do SAB (Aquíferos Marília e Adamantina) e apresentam concentrações de bário acima dos padrões de potabilidade (>0,7 mg/L). Para avaliar a origem dessas anomalias, se natural ou antrópica, assim como, avaliar o comportamento do bário no Sistema Aquifero Bauru (Aquiferos Marília e Adamantina), e sua relação com os carbonatos da Formação Marília, são utilizados neste estudo isótopos de oxigênio, hidrogênio e estrôncio, com razões isotópicas obtidas em amostras de rochas e águas subterrâneas coletadas em poços instalados nos Aquiferos Marília e Adamantina. Os resultados isotópicos de Sr indicam a origem natural de bário nas águas subterrâneas estudadas, associadas ao carbonatos da Formação Marília. A assinatura isotópica de estrôncio das águas subterrâneas (0,7090 a 0,7093) apresentam semelhança a assinatura isotópica das rochas em sua fração carbonato (0,7085 e 0,7090), indicando a origem geogênica de estrôncio, associada aos carbonatos. Considerando a tendência de correlação observada entre bário e estrôncio, pode-se concluirque os carbonatos são também a fonte potencial de bário para as águas subterrâneas. Os dados isotópicos de oxigênio e hidrogênio revelam um zoneamento isotópico do Sistema Aquífero Bauru, permitindo distinguir as águas do Aquífero Marília, enriquecidas isotopicamente (-7,11 a -7,43 para \'delta\'\'POT.18\'O e -43,57 e -49,61 para \'delta\'D) e com teores elevados de bário (1,20 a 1,60 ppm), das águas do Aquífero Adamantina, isotopicamente empobrecidas emrelação ao Aquífero Marília (-8,55 e -8,74 para \'delta\'\'POT.18\'O e -50,68 a 60,26 para \'delta\'D) e com teores inferiores de Ba (0,69 a 0,86 ppm). Dada tendência de correlação de bário com \'delta\'O \'POT.18\' , \'delta\'D e estrôncio nas águas subterrâneas, os resultados deste estudo indicam os isótopos de oxigênio, hidrogênio e estrôncio como bons traçadores das anomalias de bário nas águas subterrâneas estudadas, colocando esses isótopos como ferramentas potenciais para a gestão dos recursos hídricos subterrâneos associados ao Sistema Aquífero Bauru e suas anomalias de bário. / The monitoring of groundwater quality in the State of São Paulo executed by state environmental agency (CETESB) has identified regional problems that has caught the attention of the management bodies of the environment, water resources and water supply companies. Among the problems, anomalous levels of barium have been identified frequently in public supply wells, located primarily in Bauru Aquifer System (BAS), however, with unknown origin by CETESB. The well supply of Gália city, area chosen for this study, located between the supply wells that explore waterfrom BAS (Marília and Adamantina Aquifers) and present barium concentrations which exceeds the potability standards (> 0.7 mg / L ). To identify the origin of these anomalies, if natural or anthropogenic, as well as assess the behavior of barium in Bauru Aquifer System (Marília and Adamantina aquifers), and its relationship with the Marília Formation carbonates are used in this study isotopes of oxygen, hydrogen and strontium, with isotopic ratios obtained in samples of rocks and groundwater collected from wells installed in aquifers Marília and Adamantina. Sr isotopic results indicate the natural origin of barium in groundwater studied, associated with the Marília Formation carbonates. The strontium isotopic signature of groundwater (0,7090 a 0,7093) have similar isotopic signature of carbonate rocks in its fraction (0,7085 e 0,7090), indicating the origin geogenic of strontium, associated with carbonates. Given the tendency of correlation between strontium and barium, it canbe concluded that the carbonates are also the source of barium to groundwater. Oxygen and hydrogen isotopic data, show a isotopic zoning of the Bauru Aquifer System, allowing to distinguish between waters of the Marília Aquifer, isotopically enriched (-7.11 to -7.43 to -43.57 and -49.61 \'delta\'\'POT.18\' O and \'delta\'D for ) and with high levels of barium (1.20 to 1.60 ppm), and waters of the Aquifer Adamantina, isotopically depleted relative to Marília Aquifer (-8.55 and -8.74 for \'delta\'\'POT.18\' O and -50.68 at 60,26 for \'delta\'D) and with lower levels of Ba (0.69 to 0.86 ppm). Given trend of correlation of barium with \'delta\'\'POT.18\'O, \'delta\'D and strontium in groundwater, the results of this study indicate the isotopes of oxygen, hydrogen and strontium as good tracers of barium anomalies in groundwater study, recommending the use of these isotopes as tools formanagement of groundwater resources associated with Bauru Aquifer System and its anomalies barium.

A ocorrência de elementos químicos em águas subterrâneas tem grande importância em todo mundo devido à diversidade de seus efeitos tóxicos e ampla distribuição no meio ambiente. Entre esses elementos, podem ser citados o bário, chumbo e o crômio, que podem levar a efeitos diversos como neurotoxicidade e carcinogenicidade. O aqüífero Bauru, por ser um aqüífero freático, apresenta vulnerabilidade natural alta, podendo ocorrer contaminação devido à disposição no solo de resíduos contento estas e outras substâncias químicas. Dentro deste contexto, os objetivos deste trabalho foram: validação do método de análise e quantificação de bário, chumbo e o crômio por espectrometria de emissão atômica por plasma indutivamente acoplado ICP OES; e a determinação destes elementos em amostras de água subterrânea coletadas no aqüífero Bauru. Foram avaliados 56 pontos de coletas em 55 municípios na região ocidental do Estado de São Paulo, em duas campanhas distintas, os quais, a maioria apresentou concentrações desses elementos químicos abaixo do preconizado para consumo humano pela Resolução CONAMA n°. 396. Apresentaram valores acima do estabelecido um ponto em relação ao Bário e dez pontos em relação ao Crômio, cujos Valores Máximos Permitidos são, respectivamente, de 0,7mg.L-1Ba e 0,05mg.L-1Cr. / The occurrence of chemical element in groundwater has a great importance in the world because of the diversity of toxic effects and wide distribution in the environment. Between these chemical elements, we can cite barium, lead and chromium that can induce diverse effects such neurotoxicity and carcinogenicity. It has been considered that the aquifer Bauru has high vulnerability. Therefore the contamination may occur due to the presence of these elements in the soil related to a variety of sources. So, the objectives of this study were: the validation of the method of atomic spectrometry by inductively coupled plasma ICP OES; and the determination of these compounds in samples of groundwater collected in aquifer Bauru. We collected samples in 56 sites located in 55 municipalities in the western region of the state of São Paulo. Almost all the samples analyzed were in accordance with the Brazilian law, for drinking water proposes (Resolução CONAMA n° 396) in relation to the elements. Only 11 sites showed values above to the established: one for Barium and ten for Chromium. The threshold Values allowed for these elements are respectively, of 0.7mg.L-1Ba and 0.05mg.L-1Cr.

A videofluoroscopia da deglutição (VDF) é um exame considerado padrão ouro como método de avaliação da deglutição que requer que o paciente ingira o contraste de Bário em diferentes consistências para que as fases oral e faríngea sejam avaliadas com maior efetividade. Porém, existe uma disparidade entre a viscosidade dos alimentos com o contraste de Bário para a VDF e os alimentos espessados com o espessante de forma empírica, indicado subjetivamente na terapia de reabilitação. Por isso, o objetivo desse estudo foi: padronizar a quantidade de espessante a ser acrescentado à fórmula infantil nas consistências néctar (N), mel (M) e pudim (P) em 2 temperaturas: ambiente (T1) e variando de 40ºC até 44ºC (T2); comparar os valores médios das viscosidades com as sete marcas dos espessantes mais comumente utilizados e disponíveis (E1, E2, E3, E4, E5, E6, E7) nas temperaturas T1 e T2; identificar a quantidade mínima de contraste de Bário a ser acrescentado à fórmula infantil para boa resolução na videofluoroscopia (50%, 25% e 12,5%) e elaborar um manual de preparo de alimento para VFD nas diferentes consistências (N, M, P) com contraste de Bário. Para a padronização foram utilizados sete marcas de espessantes, uma fórmula infantil de partida, e a média da viscosidade avaliada por meio do viscosímetro Brookfield modelo DV-E, em duas temperaturas (ambiente e acima de 40ºC). Foram avaliadas três diluições (50%, 25% e 12,5%) do contraste de Bário (Bariogel 100%) nos leites espessados por meio de seringas no aparelho de VFD e as imagens obtidas julgadas por duas fonoaudiólogas experientes no exame. Os resultados revelaram que a padronização da quantidade de espessante a ser acrescentado à fórmula infantil para obtenção das consistências néctar, mel e pudim, nas temperaturas testadas, variou com o tipo de espessante, requerendo a orientação de um manual para correta manipulação. Os valores de viscosidade diminuíram com o aumento da temperatura, porém os valores foram mantidos dentro do intervalo proposto pela American Dietetic Association (2002) das consistências néctar, mel e pudim. Embora as três quantidades testadas de contraste de Bário tenham proporcionado imagens visíveis, avaliadas pelos juízes, os mesmos consideraram mais seguras aquelas observadas nas diluições de 25% e 50%, necessitando serem testadas outras situadas neste intervalo, uma vez que na diluição de 50% houve alteração da consistência néctar para mel. Um manual foi elaborado para orientação da padronização dos sete espessantes, nas três consistências e nas temperaturas testadas, bem como a sugestão de diluição do contraste de Bário no intervalo de 25% e 50%. / Videofluoroscopy (VDF) is considered a gold standard exam as an evaluation method for swallowing which requires that the patient ingests the Barium contrast in different consistencies so the oral and pharyngeal stages are evaluated with greater effectiveness. However, there is a difference between the viscosity of food with barium contrast for the VDF and thickened foods with the thickener, indicated subjectively in rehabilitation therapy. Therefore, the aim of this study was to standardize the amount of thickener to be added to infant formula in the following consistencies: nectar (N), honey (M) and (P) pudding in 2 environmental temperatures: (T1) and ranging from-40 degrees C to 44 C (T2); compare the average values of viscosities with seven brands of thickening agents most commonly used and available (E1, E2, E3, E4, E5, E6, E7) at temperatures T1 and T2; identify the minimal amount of barium contrast to be added to infant formula for good resolution in videofluoroscopy (50%, 25% and 12.5%), and elaborate a manual of food preparation to VFD in different consistencies (N, M, P) with Barium contrast. Seven brands of thickeners, an infant formula, and the average viscosity evaluated by Brookfield viscometer model DV-E, in two temperatures (above 40°C and environment) were used for standardization. Three dilutions (50%, 25% and 12.5%) of Barium contrast (Bariogel 100%) were used to evaluate the thickened milk by syringes into the VFD and the images obtained judged by two experienced speech language pathologists. Results revealed that the standardization of the amount of thickener to be added to infant formula to obtain the nectar, honey and pudding consistencies, in tested temperatures, varied according to the type of thickener, requiring the use of a manual for correct handling. Viscosity values decreased with increasing temperature, but the values were maintained within the range proposed by the American Dietetic Association (2002) regarding nectar, honey and pudding consistencies. Although the three tested quantities of Barium contrast have provided visible images, evaluated by the judges, those observed in dilutions of 25% and 50% were considered safer. It demanded tests in others situated in this range once in the dilution of 50% there was a change from nectar to honey consistency. A manual has been prepared for the guidance on the standardization of seven thickeners, in the three tested.

Three systems of electrospun composite membranes with piezoelectric polymer polyvinylidene fluoride (PVDF) as matrix incorporating: 1) Carbon based fillers: carbon nanotube (CNT) and graphene oxide (GO); 2) Ceramic based fillers-barium titanate (BT), zinc oxide (ZnO) and nanoclays (halloysite and bentonite); 3) Cellulosic fillers: microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC) at different loadings were prepared by electrospinning process. Influence of filler type and loading on total PVDF crystallinity (Xc), relative fraction of β phase (piezoelectric phase) in total crystalline PVDF (Fβ), volume fraction of β phase in the samples (vβ) and piezoelectric coefficient d33 were characterised and analysed. Correlation between vβ and piezoelectric performance (d33) will be focused by this work. A common situation was observed for the composites-d33 increased while vβ is reduced by the fillers, so it can be concluded that d33 of the composites is not totally up to their vβ, there are other factors that need to be taken into account. For example, for carbon based filler like CNT, it increased electric conductivity of sample during and after electrospinning process, making it easier for charges produced by β crystals from inside of sample to be transferred to surfaces of the sample, and possibly promoting orientation of β crystals in d33 direction, therefore enhanced d33 of the composites though β phase formation was significantly hindered by inclusion of CNT; For piezoelectric ceramic fillers like BT and ZnO, a possible combined piezoelectricity from filler and β phase PVDF might enhanced d33 though less β phase was formed; And for non-piezoelectric and non-conductive fillers, enhancement in orientation of β crystals might play a major role in promotion of d33. Keywords: electrospinning; polyvinylidene fluoride (PVDF); nanocomposites; piezoelectric coefficient d33; energy harvesting.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16396号 / 工博第3477号 / 新制||工||1525(附属図書館) / 29027 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 乾 晴行, 准教授 宇田 哲也 / 学位規則第4条第1項該当

Doctor of Philosophy / Department of Chemistry / Kenneth J. Klabunde / A new approach to synthesize nanosized strontium titanate (SrTiO3) and barium titanate (BaTiO3) has been developed. Nanocrystals of mixed metal oxide were synthesized by a modified aerogel procedure from alkoxides. The textural and surface characteristic properties were studied by nitrogen BET analysis, transmission electron microscopy, and powder XRD. The crystallite sizes of aerogel prepared powders can vary from 6 to 25 nm by the use of different solvents. A mixture of ethanol and toluene was found to be the best binary solvent for supercritical drying, which produced a SrTiO3 sample with a surface area of 159 m2/g and an average crystallite size of 8 nm, and a BaTiO3 sample with a surface area of 175 m2/g and an average crystallite size of 6 nm. These titanates have been studied for photocatalytic oxidation of volatile organic compounds and acetaldehyde (CH3CHO) in particular. The big band gaps of the bulk (3.2 eV for SrTiO3 and 3.1 eV for BaTiO3) limit their application to a UV light region only. The modification of titanates by doping with transition metal ions (partial substitution of Ti ions with metal ions) creates a valence band or electron donor level inside of the band gap, narrows it, and increases the visible light absorption. The enhanced adsorption of visible light was achieved by the synthesis of nanosized SrTiO3 and BaTiO3 by incorporating Cr ions during the modified aerogel procedure. Gaseous acetaldehyde photooxidation has been studied on pure SrTiO3 and BaTiO3, and on chromium doped Cr-SrTiO3 and Cr-BaTiO3 under UV and visible light irradiation, and compared with the photoactivity of P25 TiO2. SrTiO3 doped with antimony/chromium shows absorption in visible light and show photocatalytic activity for CH3CHO oxidation. The reason for the codoping of SrTiO3 with Sb/Cr was to maintain the charge balance and to suppress oxygen defects in the lattice. This photocatalyst shows high photoactivity under visible light irradiation even after several continuous runs. The photoactivity under visible and UV light irradiation was almost identical for the Sb/Cr-SrTiO3 photocatalyst. Dielectric properties of aerogel prepared barium titanate samples have being studied and the bulk resistance values of AP-BaTiO3 were significantly lower than that of commercial BaTiO3, by several orders of magnitude.

Low temperature sintering has become a very important research area in ceramics processing and sintering as a promising process to obtain grain size below 100nm. For electronic ceramics, low temperature sintering is particularly difficult, because not only the required microstructure but also the desired electronic properties should be obtained. In this dissertation, the effect of liquid sintering aids and particle size (micrometer and nanometer) on sintering temperature and Positive Temperature Coefficient Resistivity (PTCR) property are investigated for Ba1-xSrxTiO3 (BST) doped with 0.2-0.3mol% Sb3+ (x = 0.1,0.2,0.3,0.4 and 0.5). Different sintering aids with low melting point are used as sintering aids to decrease the sintering temperature for micrometer size BST particles. Micrometer size and nanometer size Ba1-xSrxTiO3 (BST) particles are used to demonstrate the particle size effect on the sintering temperature for semiconducting BST. To reduce the sintering temperature, three processes are developed, i.e. 1 using sol-gel nanometer size Sb3+ doped powders with a sintering aid; 2 using micrometer size powders plus a sintering aid; and 3 using nanometer size Sb3+ doped powders with sintering aids. Grain size effect on PTCR characteristics is investigated through comparison between micrometer size powder sintered pellets and nanometer size powder sintered pellets. The former has lower resistivity at temperatures below the Curie temperature (Tc) and high resistivity at temperatures above the Curie temperature (Tc) along with higher ñmax/ñmin ratio (ñmax is the highest resistivity at temperatures above Tc, ñmin is the lowest resistivity at temperatures below Tc), whereas the latter has both higher ñmax and ñmin. Also, ñmax/ñmin is smaller than that of pellets with larger grain size. The reason is that the solid with small grain size has more grain boundaries than the solid with large grain size. The contribution z at room temperature and high temperature and a lower ñmax/ñmin ratio value.

A modified thin lens spectrometer has been used with improved geometry. The focussing properties of the instrument have been investigated for various geometries. Using this instrument the conversion electron spectra of Sn¹¹³ and Sb¹²⁵ have been taken. The intensity of the 256 kev conversion line in Sn¹¹³ spectrum showed that this transition is predominantly M1 in character and therefore the spin and parity of 648-kev level in In¹¹³ should be 1/2¯ or 3/2¯. The low energy part of the conversion spectrum of Sb¹²⁵showed the presence of the K conversion lines of 76 kev and 143 kev transitions, not observed before. The presence of these conversion lines confirmed the existence of a weak beta group feeding a level at 540 kev in the excited state of Te¹²⁵. The energy levels of Cs¹³³ have been studied through the decay of Ba¹³³. Scintillation spectra (using NaI(T1 ) crystal) together with photoelectron, conversion and e-gamma coincidence spectra have been taken. An analysis of the results indicate that the ground state and 81, 161, 383 and 437 kev levels in Cs¹³³ have spins and parities of 7/2⁺, 5/2⁺,5/2⁺,3/2⁺, 1/2⁺ respectively. The multipolarities of the connecting transitions are 383 kev (E2 ), 356 (E2 ) 302 kev (M1 with E2 admixture)} 276 kev (E2 ), 161 kev (probably M1 ) Electron capture from Ba¹³³ is limited almost entirely to the 437 and 383 kev levels in Cs¹³³, The decay energy available for capture to the 437 level is approximately 50 kev. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Portland clinker is thanks to its large-scale production a continuously studied topic. Clinker, or Portland cement, is used for construction purposes, or for insulation and special applications. One of these special applications could be shielding of different types of radiation by making use of the content of barium ions. The present master’s thesis examines the influence of barium oxide on the formation and properties of Portland clinker, which could be, by incorporation of barium ions into the system, used as a binder for buildings resistant to various types of radiation. Barium sulfate and barium carbonate were added to the raw meal in order to prepare clinkers with different content of barium oxide. The effect of barium on the formation of clinker phases was studied (by XRD – Rietveld analysis and by the microscopic point integration), as well as the effects on the variations of temperature of the phase formation (TG-DTA) and the rate of alite formation under isothermal conditions. Furthermore, the ability of barium to become a part of clinker minerals was studied by SEM with EDS, and the solubility of barium phases by ICP-OES. The hydration of clinker minerals containing barium was studied by isothermal calorimetry.