O presente estudo objetivou a caracterização hidrogeoquímica ao longo da bacia de drenagem do rio Sorocaba - São Paulo, em cinco estações de amostragens, localizadas desde a região de nascentes, estação S5- Ibiúna, passando por áreas com maior influencia urbana e agrícola (S4 - Votarantim, S3 - Itavuvu e S2 - Tatuí), até a foz da bacia em estudo, S1 - Laranjal Paulista, utilizando-se modelos de transporte de materiais nas fases dissolvidas e particuladas. Para tal, foram realizadas coletas ao longo de 18 meses, de amostras de águas fluviais, pluviais, sedimento fino em suspensão (FSS) e dos principais tipos solos integrantes da bacia. Importantes parâmetros físico-quimicos e a caracterização das cargas dissolvida e particulada foram determinados. As características hidroquímicas das águas fluviais mostraram que as espécies químicas SiO2, Ca2+, Mg2+, K+, HCO3- e TDS indicaram possíveis aportes difusos e as espécies Na+, Cl-, SO42-, PO43-, NH4+ e NO3-indicaram origens pontuais. O elemento químico dissolvido que mais contribuiu no transporte específico fluvial junto à foz do rio Sorocaba (S1- Laranjal Paulista), foi o Na+ para os cátions (24,25, kg km-2 d-1) e para os ânions foi o HCO3- com 53,97 kg km-2 d-1. Já no transporte pluvial o Ca2+ foi a espécie química que apresentou maior contribuição na carga do rio com 54,89 %. Com relação ao material particulado, representada pelo FSS, o transporte específico variou de 22,68 a 55,70 t km-2 a-1, desde a região das nascentes até a foz, respectivamente. O rio Sorocaba foi classificado como médio transportador de sedimento fino em suspensão e a erosão mecânica foi de 37,88 m.Ma-1 / This study aimed to characterize the hydrogeochemical along the Sorocaba river basin (SP), in five sampling stations, located from the headwaters region, S5-Ibiúna station, passing through areas with higher urban and agricultural influences (S4 - Votorantim, S3 - Itavuvu and S2 and Tatuí, to the mouth of the basin under study, S1 - Laranjal Paulista, using models of transport on dissolved and particulate phases. Samples of river water, pluvial, fine suspended sediment (FSS) and the main soils types were collected over 18 months. Important physico-chemical characterization of dissolved and particulate loads were determined. The hydrochemical features of the river water showed that the chemical species SiO2, Ca2 +, Mg2+, K +, HCO3-and TDS indicated possible diffuse contributions and species Na +, Cl-, SO42-, PO43-, NH4+ and NO3-indicated origin contributions. The dissolved chemical element who more contributed in transport dissolved specific in S1-Laranjal Paulista), was Na+ for cations, with 24,25 kg km-2 d-1 and for anions was HCO3- with 53.97 kg km-2 d-1. In the rain Ca2+ was the chemical species with the highest contribution to the river load with 54.89%. The suspended particulate matter, represented by the FSS, the specific transport ranged from 22.68 to 55.70 t km-2 a-1, from the region of the headwaters to the mouth, respectively. The river was classified as medium transporting fine sediment in suspension and the mechanical erosion was the 37.88 m .Ma-1

O presente estudo objetivou a caracterização hidrogeoquímica ao longo da bacia de drenagem do rio Sorocaba - São Paulo, em cinco estações de amostragens, localizadas desde a região de nascentes, estação S5- Ibiúna, passando por áreas com maior influencia urbana e agrícola (S4 - Votarantim, S3 - Itavuvu e S2 - Tatuí), até a foz da bacia em estudo, S1 - Laranjal Paulista, utilizando-se modelos de transporte de materiais nas fases dissolvidas e particuladas. Para tal, foram realizadas coletas ao longo de 18 meses, de amostras de águas fluviais, pluviais, sedimento fino em suspensão (FSS) e dos principais tipos solos integrantes da bacia. Importantes parâmetros físico-quimicos e a caracterização das cargas dissolvida e particulada foram determinados. As características hidroquímicas das águas fluviais mostraram que as espécies químicas SiO2, Ca2+, Mg2+, K+, HCO3- e TDS indicaram possíveis aportes difusos e as espécies Na+, Cl-, SO42-, PO43-, NH4+ e NO3-indicaram origens pontuais. O elemento químico dissolvido que mais contribuiu no transporte específico fluvial junto à foz do rio Sorocaba (S1- Laranjal Paulista), foi o Na+ para os cátions (24,25, kg km-2 d-1) e para os ânions foi o HCO3- com 53,97 kg km-2 d-1. Já no transporte pluvial o Ca2+ foi a espécie química que apresentou maior contribuição na carga do rio com 54,89 %. Com relação ao material particulado, representada pelo FSS, o transporte específico variou de 22,68 a 55,70 t km-2 a-1, desde a região das nascentes até a foz, respectivamente. O rio Sorocaba foi classificado como médio transportador de sedimento fino em suspensão e a erosão mecânica foi de 37,88 m.Ma-1 / This study aimed to characterize the hydrogeochemical along the Sorocaba river basin (SP), in five sampling stations, located from the headwaters region, S5-Ibiúna station, passing through areas with higher urban and agricultural influences (S4 - Votorantim, S3 - Itavuvu and S2 and Tatuí, to the mouth of the basin under study, S1 - Laranjal Paulista, using models of transport on dissolved and particulate phases. Samples of river water, pluvial, fine suspended sediment (FSS) and the main soils types were collected over 18 months. Important physico-chemical characterization of dissolved and particulate loads were determined. The hydrochemical features of the river water showed that the chemical species SiO2, Ca2 +, Mg2+, K +, HCO3-and TDS indicated possible diffuse contributions and species Na +, Cl-, SO42-, PO43-, NH4+ and NO3-indicated origin contributions. The dissolved chemical element who more contributed in transport dissolved specific in S1-Laranjal Paulista), was Na+ for cations, with 24,25 kg km-2 d-1 and for anions was HCO3- with 53.97 kg km-2 d-1. In the rain Ca2+ was the chemical species with the highest contribution to the river load with 54.89%. The suspended particulate matter, represented by the FSS, the specific transport ranged from 22.68 to 55.70 t km-2 a-1, from the region of the headwaters to the mouth, respectively. The river was classified as medium transporting fine sediment in suspension and the mechanical erosion was the 37.88 m .Ma-1

O estudo da microbacia de drenagem do córrego Barra Bonita, (S: 22º 25\' 53,9\" ; O: 48º 32\' 34,8\") objetivou a caracterização de seus parâmetros hidrogeoquímicos utilizando-se os modelos de transporte de materiais nas fases dissolvida e particulada para identificar as relações entre os processos de ocupação do solo e qualidade da água. Pelo fato de não existir um zoneamento ambiental no município, este estudo foi pioneiro investigação da qualidade ambiental da microbacia, contribuindo diretamente em futuros planos de conservação e utilização de suas águas superficiais para abastecimento público. O estudo foi conduzido de setembro de 2005 a dezembro de 2006 em quatro córregos principais formadores da microbacia, sendo selecionados oito pontos de amostragem de montante a jusante para coletas de água durante as diferentes fases da hidrógrafa. Além disso, uma amostragem intensiva foi realizada durante um evento de chuva para melhor acompanhamento dos mecanismos de transporte de materiais dissolvidos e particulados. O protocolo analítico empregado neste estudo possibilitou a determinação de variáveis hidrogeoquímicas como vazão, concentração de sedimentos em suspensão e sua caracterização isotópica quanto ao carbono e nitrogênio orgânico particulado, concentração de íons maiores dissolvidos, transporte de material dissolvido e particulado, concentração de metais em solução, sua biodisponibilidade nos sedimentos aquáticos, separação das componentes superficial e subterrâneo no escoamento total da microbacia e mecanismos de aporte difuso e pontual da carga dissolvida e particulada em escalas espaciais e temporais. Com relação ao material dissolvido na microbacia, as espécies químicas apresentaram comportamento de diluição com o aumento das vazões, predominando, portanto os aportes pontuais de carga dissolvida na microbacia. Por outro lado, durante o evento de chuva estudado as concentrações apresentaram aumento em função das vazões, destacando-se a origem superficial das espécies química nestas condições. As espécies químicas predominantes foram o HCO3-, Na+ e Ca2+, as quais estiveram relacionadas tanto à formação geológica da região quanto à aportes pontuais por meio de aplicação de insumos agrícolas como gesso, calcário e vinhaça. A parte agrícola da microbacia apresentou maior contribuição à carga dissolvida transportada durante o período considerado como chuvoso, enquanto os aportes pontuais de efluentes domésticos e de águas urbanas sobressaíram-se durante o período de seca. O material particulado em suspensão apresentou correlacionamento significativo com o incremento das vazões, sendo a parte agrícola a principal responsável pela carga transportada pela microbacia. A caracterização isotópica do material orgânico particulado para o carbono e nitrogênio evidenciou os processos de fracionamento da assinatura isotópica da matriz de plantas C4 (cana de açúcar) presente na microbacia, estando tais processos mais relacionados à degradação do material orgânico presente no solo, bem como do aporte de poluição originado da parte urbana. Apenas durante eventos de maior escoamento rápido superficial, o carbono orgânico particulado do sedimento em suspensão se aproximou do \"delta\"% das plantas C4. As concentrações de metais dissolvidos foram bastante baixas conforme o esperado, destacando-se o Fe e Al que estiveram mais relacionados ao tipo de solo da região. A biodisponibilidade de metais nos sedimentos aquáticos também foi baixa em relação a bacias hidrográficas mais industrializadas. / The study in the Barra Bonita stream small watershed (S: 22o 25\' 53,9\" and W: 48o 32\' 34,8\") aimed to characterize its hydrogeochemical parameters by dissolved and particulate material transport models to identify the relations between soil use and water quality. Because there was no longer an environmental zoning in the municipality of Barra Bonita, this study was pioneer on the watershed environmental investigation, which may contribute directly to future conservation plans for the utilization of this water source as public supplying. The study was conducted from September 2005 to December 2006 in four main watershed tributaries where eight sampling points were established, upstream to downstream, for water sampling along with the hidrogram phases. Besides that, an intensive sampling excursion was carried out during a storm event in order to achieve better data about the dissolved and particulate material transport. In this study were analyzed the following hydrogeochemical parameters: discharge, major dissolved ions, suspended sediments concentrations and their isotopic characterization for particulate carbon and nitrogen, dissolved and particulate transport, dissolved metals concentration and the biodisponibilty of metal from the bottom aquatic sediments, superficial and sub superficial components of the total discharge and the punctual and diffuse input mechanisms of dissolved and particulate load for spatial and time scales. For the dissolved material in the watershed the major chemical species presented decreased concentrations with the discharge, showing the dominance of punctual input processes in the watershed. On the other hand during the storm flow event the ions concentrations increased with the discharge, showing their superficial origins in this condition. The dominant chemical species were HCO3-, Na+ and Ca2+, which were related to the regional geological formation and punctual input by agriculture like gypsum, liming and stillage. The agricultural area of the watershed presented the major contribution to the transported dissolved load in thee rainy period while the punctual inputs of domestic sewage and urban waters more important in the dry period. The suspended particulate material showed significant correlation with the discharge increasing and the agricultural part was source of the total transported load in the watershed. The isotopic characterization of the particulate organic carbon and nitrogen showed the fractioning processes of the isotopic signature from the C4 plants (sugarcane) matrix presented in the watershed, which were more related to the soil organic matter mineralization as well as with the pollution input from the urban area Only at high flows periods the particulate organic carbon was to the C4 \"delta\"% values. The dissolved metals concentrations were low as previewed, except for Fe and Al that were related to the regional soil types. The metals biodisponibility in the bottom aquatic sediments were also low in relation to more industrialized regions

O estudo da microbacia de drenagem do córrego Barra Bonita, (S: 22º 25\' 53,9\" ; O: 48º 32\' 34,8\") objetivou a caracterização de seus parâmetros hidrogeoquímicos utilizando-se os modelos de transporte de materiais nas fases dissolvida e particulada para identificar as relações entre os processos de ocupação do solo e qualidade da água. Pelo fato de não existir um zoneamento ambiental no município, este estudo foi pioneiro investigação da qualidade ambiental da microbacia, contribuindo diretamente em futuros planos de conservação e utilização de suas águas superficiais para abastecimento público. O estudo foi conduzido de setembro de 2005 a dezembro de 2006 em quatro córregos principais formadores da microbacia, sendo selecionados oito pontos de amostragem de montante a jusante para coletas de água durante as diferentes fases da hidrógrafa. Além disso, uma amostragem intensiva foi realizada durante um evento de chuva para melhor acompanhamento dos mecanismos de transporte de materiais dissolvidos e particulados. O protocolo analítico empregado neste estudo possibilitou a determinação de variáveis hidrogeoquímicas como vazão, concentração de sedimentos em suspensão e sua caracterização isotópica quanto ao carbono e nitrogênio orgânico particulado, concentração de íons maiores dissolvidos, transporte de material dissolvido e particulado, concentração de metais em solução, sua biodisponibilidade nos sedimentos aquáticos, separação das componentes superficial e subterrâneo no escoamento total da microbacia e mecanismos de aporte difuso e pontual da carga dissolvida e particulada em escalas espaciais e temporais. Com relação ao material dissolvido na microbacia, as espécies químicas apresentaram comportamento de diluição com o aumento das vazões, predominando, portanto os aportes pontuais de carga dissolvida na microbacia. Por outro lado, durante o evento de chuva estudado as concentrações apresentaram aumento em função das vazões, destacando-se a origem superficial das espécies química nestas condições. As espécies químicas predominantes foram o HCO3-, Na+ e Ca2+, as quais estiveram relacionadas tanto à formação geológica da região quanto à aportes pontuais por meio de aplicação de insumos agrícolas como gesso, calcário e vinhaça. A parte agrícola da microbacia apresentou maior contribuição à carga dissolvida transportada durante o período considerado como chuvoso, enquanto os aportes pontuais de efluentes domésticos e de águas urbanas sobressaíram-se durante o período de seca. O material particulado em suspensão apresentou correlacionamento significativo com o incremento das vazões, sendo a parte agrícola a principal responsável pela carga transportada pela microbacia. A caracterização isotópica do material orgânico particulado para o carbono e nitrogênio evidenciou os processos de fracionamento da assinatura isotópica da matriz de plantas C4 (cana de açúcar) presente na microbacia, estando tais processos mais relacionados à degradação do material orgânico presente no solo, bem como do aporte de poluição originado da parte urbana. Apenas durante eventos de maior escoamento rápido superficial, o carbono orgânico particulado do sedimento em suspensão se aproximou do \"delta\"% das plantas C4. As concentrações de metais dissolvidos foram bastante baixas conforme o esperado, destacando-se o Fe e Al que estiveram mais relacionados ao tipo de solo da região. A biodisponibilidade de metais nos sedimentos aquáticos também foi baixa em relação a bacias hidrográficas mais industrializadas. / The study in the Barra Bonita stream small watershed (S: 22o 25\' 53,9\" and W: 48o 32\' 34,8\") aimed to characterize its hydrogeochemical parameters by dissolved and particulate material transport models to identify the relations between soil use and water quality. Because there was no longer an environmental zoning in the municipality of Barra Bonita, this study was pioneer on the watershed environmental investigation, which may contribute directly to future conservation plans for the utilization of this water source as public supplying. The study was conducted from September 2005 to December 2006 in four main watershed tributaries where eight sampling points were established, upstream to downstream, for water sampling along with the hidrogram phases. Besides that, an intensive sampling excursion was carried out during a storm event in order to achieve better data about the dissolved and particulate material transport. In this study were analyzed the following hydrogeochemical parameters: discharge, major dissolved ions, suspended sediments concentrations and their isotopic characterization for particulate carbon and nitrogen, dissolved and particulate transport, dissolved metals concentration and the biodisponibilty of metal from the bottom aquatic sediments, superficial and sub superficial components of the total discharge and the punctual and diffuse input mechanisms of dissolved and particulate load for spatial and time scales. For the dissolved material in the watershed the major chemical species presented decreased concentrations with the discharge, showing the dominance of punctual input processes in the watershed. On the other hand during the storm flow event the ions concentrations increased with the discharge, showing their superficial origins in this condition. The dominant chemical species were HCO3-, Na+ and Ca2+, which were related to the regional geological formation and punctual input by agriculture like gypsum, liming and stillage. The agricultural area of the watershed presented the major contribution to the transported dissolved load in thee rainy period while the punctual inputs of domestic sewage and urban waters more important in the dry period. The suspended particulate material showed significant correlation with the discharge increasing and the agricultural part was source of the total transported load in the watershed. The isotopic characterization of the particulate organic carbon and nitrogen showed the fractioning processes of the isotopic signature from the C4 plants (sugarcane) matrix presented in the watershed, which were more related to the soil organic matter mineralization as well as with the pollution input from the urban area Only at high flows periods the particulate organic carbon was to the C4 \"delta\"% values. The dissolved metals concentrations were low as previewed, except for Fe and Al that were related to the regional soil types. The metals biodisponibility in the bottom aquatic sediments were also low in relation to more industrialized regions

This study is focuses on the resistance switching physical mechanism in hafnium oxide (HfO2) of resistive random access memory (RRAM). HfO2 was taken as the resistance switching layer because HfO2 is extremely compatible with the prevalent complementary metal oxide semiconductor (CMOS) process. The detail physical mechanism is studied by the stable RRAM device (Ti/HfO2/TiN), which is offered from Industrial Technology Research Institute (ITRI). In this study, the resistance switching property of two different forming conductions are compared, including DC sweeping forming and AC pulse forming. In general, forming is a pivotal process in resistance random access memory (RRAM) to activate the resistance switching behavior. However, over forming would lead to device damage. The overshoot current has been considered as a degradation reason during the forming process. The circuit design is used to obtain the overshoot effect of DC sweeping forming by oscilloscope and semiconductor parameter analyzer system. The quantity of charge through the switching layer has been proven as the key element in the formation of the conduction path. Ultra-fast pulse forming can form a discontinuous conduction path to reduce the operation power.

abstract: Graphene oxide membranes have shown promising gas separation characteristics specially for hydrogen that make them of interest for industrial applications. However, the gas transport mechanism for these membranes is unclear due to inconsistent permeation and separation results reported in literature. Graphene oxide membranes made by filtration, the most common synthesis method, contain wrinkles affecting their gas separation characteristics and the method itself is difficult to scale up. Moreover, the production of graphene oxide membranes with fine-tuned interlayer spacing for improved molecular separation is still a challenge. These unsolved issues will affect their potential impact on industrial gas separation applications. In this study, high quality graphene oxide membranes are synthesized on polyester track etch substrates by different deposition methods and characterized by XRD, SEM, AFM as well as single gas permeation and binary (H2/CO2) separation experiments. Membranes are made from large graphene oxide sheets of different sizes (33 and 17 micron) using vacuum filtration to shed more light on their transport mechanism. Membranes are made from dilute graphene oxide suspension by easily scalable spray coating technique to minimize extrinsic wrinkle formation. Finally, Brodie’s derived graphene oxide sheets were used to prepare membranes with narrow interlayer spacing to improve their (H2/CO2) separation performance. An inter-sheet and inner-sheet two-pathway model is proposed to explain the permeation and separation results of graphene oxide membranes obtained in this study. At room temperature, large gas molecules (CH4, N2, and CO2) permeate through inter-sheet pathway of the membranes, exhibiting Knudsen like diffusion characteristics, with the permeance for the small sheet membrane about twice that for the large sheet membrane. The small gases (H2 and He) exhibit much higher permeance, showing significant flow through an inner-sheet pathway, in addition to the flow through the inter-sheet pathway. Membranes prepared by spray coating offer gas characteristics similar to those made by filtration, however using dilute graphene oxide suspension in spray coating will help reduce the formation of extrinsic wrinkles which result in reduction in the porosity of the inter-sheet pathway where the transport of large gas molecules dominates. Brodie’s derived graphene oxide membranes showed overall low permeability and significant improvement in in H2/CO2 selectivity compared to membranes made using Hummers’ derived sheets due to smaller interlayer space height of Brodie’s sheets (~3 Å). / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2018

No description available.

This work provides information about interactions that produce emitted electrons from polycrystalline Au. Emission energy- angle- dependent electron spectra from a polycrystalline Au surface have been measured at several incident electron beam energies. The range of incident energies (~100 eV to 2500 eV) extends from below the first crossover energy, through Emaxo, to above the second crossover energy. The conventional distinction between secondary electrons (SE) (50 eV) is found to be crude for the investigation of electron yields using these energy- angle- resolved measurements. A more realistic boundary occurs at the local minima of the emission spectra; this feature is studied as a function of incident energy and emission angle. In addition, deviations observed in the angular resolved emission spectra from isotropic behavior suggests that residual signatures exist in the emission spectra resulting from the anisotropic SE production mechanisms. Based on the disparity between our observations and recent modeling of the emission spectra, the most recent theory and simulation studies may overestimate the occurrence of randomizing collisions of scattered secondary electrons in the model of the transport mechanism. Finally, description of extensive modification to instrumental and analysis methods are described, and their effectiveness is evaluated.

Ammonia excretion from the freshwater fish gill is thought to occur mainly via passive diffusion of NH3 aided by a favourable plasma-to-water ammonia gradient sustained by a pH gradient formed by an acidified gill boundary layer. Rhesus (Rh) proteins are the newest members of the ammonia transporter superfamily. In this thesis research, ten rainbow trout Rh cDNA sequences were cloned and characterized. Rhcg2 mRNA and H+-ATPase mRNA and activity levels were upregulated in the trout gill pavement cells in response to experimentally elevated plasma ammonia, concurrent with enhanced ammonia excretion. Controversially, Rh proteins are thought to transport C02. However, Rh mRNA levels in most tissues of hypercapnia-exposed trout remained stable suggesting that trout Rh proteins likely do not conduct C02. Xenopus oocytes expressing trout Rh proteins facilitated the bi-directional transport of methylamine, an ammonia analogue. Methylamine transport was inhibited by ammonia and sensitive to a pH gradient and the concentration of the protonated species. Use of the scanning ion electrode technique (SIET) indicated that trout Rh proteins have an ammonia affinity within the physiological range, which is greater than that for methylamine, and they transport ammonia more rapidly than methylamine. A model of ammonia excretion in the trout gill pavement cell is proposed wherein ammonia enters via basolateral Rhbg and exits via apical Rhcg2, binding to these channels as NH4+ but transiting as NH3. In the gill boundary layer, NH3 combines with an H+ ion released from H+-ATPase and/or Na+/H+ exchange, forming NH4+. As low-affinity, high-capacity ammonia transporters, Rh proteins in the trout gill would exploit the favourable pH gradient formed by the acidic boundary layer to facilitate rapid ammonia efflux when plasma ammonia levels are elevated. Basal plasma ammonia levels are likely maintained by simple passive NH3 diffusion with a smaller role for Rh proteins under these conditions. / Thesis / Doctor of Philosophy (PhD)

No description available.