Made available in DSpace on 2016-12-08T17:19:19Z (GMT). No. of bitstreams: 1 Elton G dos Reis.pdf: 2166812 bytes, checksum: 384c9af44058a93b40c48b5b2bf1e226 (MD5) Previous issue date: 2012-12-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to characterize the mechanical properties of the fiber and taquaralixa (Merostachys sp.) composites with polyester and epoxy matrixes by means of tensile, pull out and flexural tests. Initially, the stalks of taquara went through a drying process to determine the moisture content. Afterwards, the taquara sticks were chemically treated with a solution of sodium hydroxide 10% w/w and hydrogen peroxide 10% v/v, causing softening of the sticks that later were crushed with a rolling machine, in order to partially remove lignin and separate the fibers. To determine the tensile strength of the fiber, tensile tests were performed. And fiber was tested by means of pull out test for determining the shear stress and critical length in the polyester and epoxy matrixes. An optic microscope and an application software were used to determine the cross-sectional area and the perimeter of the fiber. Composites with long fibers and matrixes of polyester and epoxy were prepared through the compression molding process. The fiber concentrations used in the polyester matrix were: 40, 60, 70 and 75% w/w; and for the epoxy matrix 40, 60 and 75% w/w of fiber were used. Composites with random and short fibers were produced with epoxy matrix. Fibers with 13 mm in length were used at the concentrations of 50 and 60% w/w; fibers with 25 mm in length at concentrations of 50 and 60% w/w and fibers with 60 mm in length at a concentration of 50% w/w. Flexural tests were performed for the composites and it was possible to determine the flexural stress, Young s Modulus, strain and density for each specimen. From the results of the long fibers composites and using the values of tensile and strain within the linear region, the Young s modulus of the fiber was estimated through interpolation of the rule of mixtures lower limit and Halpin-Tsai equations. For the results of composites with random and short fibers together with the results of composites with long fibers and epoxy matrix, the rule of mixtures lower limit equation was interpolated in order to obtain an estimate of the Young s modulus or tensile strength in function of the volumetric fraction and fiber length. With the results of tensile strength, Young s modulus and density, it was possible to perform a comparison among the mechanical properties of wood Angicovermelho (Anadenanthera peregrina), Peróba-rosa (Aspidosperma polyneuron), Piquiá (Caryocar villosum) and Eucalipto (Eucalyptus Grandis and Citriodora). Composites with long fibers and composites with 60 mm in lenght of fibers presented superior properties in comparison to these woods. / Este trabalho teve como objetivo caracterizar as propriedades mecânicas da fibra e os compósitos de fibra de taquara-lixa (Merostachys sp.) com matriz poliéster e epóxi por meio de ensaios de tração, pull out e flexão de três pontos. Inicialmente, os colmos da taquara passaram por um processo de secagem para a determinação do teor de umidade. Em seguida, os gravetos da taquara foram tratados quimicamente com solução de hidróxido de sódio a 10% m/m e peróxido de hidrogênio a 10% v/v que provocou o amolecimento dos gravetos que na sequência foram esmagados com auxílio de uma calandra, com o objetivo de retirar parcialmente a lignina e separar as fibras. Os ensaios de tração da fibra foram realizados para a determinação da tensão de ruptura. E ensaios de pull out da fibra foram realizados para a determinação da tensão cisalhante de ruptura e comprimento crítico nas matrizes poliéster e epóxi. Para a determinação da área transversal e perímetro da fibra foi utilizado um microscópio óptico e um aplicativo de tratamento de imagem. Compósitos com fibras longas e matrizes de poliéster e epóxi foram confeccionados por meio do processo de moldagem por compressão. As concentrações de fibras utilizadas para a matriz poliéster foram 40, 60, 70 e 75% m/m e para a matriz epóxi foram 40, 60 e 75% m/m. Compósitos com fibras curtas e aleatórias também foram produzidos com matriz epóxi. Foram utilizadas fibras com 13 mm de comprimento nas concentrações de 50 e 60% m/m de fibra, 25 mm de comprimento nas concentrações de 50 e 60% m/m e 60 mm de comprimento na concentração de 50% m/m. Ensaios de flexão de 3 pontos foram realizados para os compósitos, e determinou-se a tensão de flexão, o módulo de elasticidade, a deformação e a massa específica para cada corpo de prova. A partir dos resultados obtidos dos compósitos com fibras longas e utilizando-se os valores de tensão e deformação dentro do regime linear, foi possível estimar o módulo de elasticidade da fibra por meio da interpolação das equações da regra das misturas limite inferior e equação de Halpin-Tsai. Para os resultados dos compósitos com fibras curtas e aleatórias juntamente com os resultados dos compósitos com fibras longas e matriz epóxi foi interpolada a equação da regra das misturas limite inferior com o objetivo de obter uma estimativa do módulo de elasticidade ou da tensão de flexão em função da fração volumétrica, e comprimento da fibra. Com os resultados de tensão de flexão, módulo de elasticidade e massa específica foi possível realizar uma comparação em relação as propriedades mecânicas das madeiras Angico-vermelho (Anadenanthera peregrina), Peróba-rosa (Aspidosperma Polyneuron), Piquiá (Caryocar villosum) e Eucalipto (Eucaliptus Citriodora e Grandis). Os compósitos com fibras longas e fibras curtas de 60 mm apresentaram propriedades superiores em comparação com estas madeiras.

La gestión integral de residuos químicos permite minimizar la cantidad de residuos generados, reaprovechar los residuos que puedan volver a ser utilizados, tratarlos para disminuir su peligrosidad, y real izar una disposición final segura de aquellos residuos que no puedan ser reducidos. Se presentan los principios de gestión, el análisis del ciclo de vida de un residuo y diversas opciones de tratamiento (físico, químico, térmico y biológico) para la disposición final. / Integral management of chemical wastes generated in industrial activitiesThe integral management of chemical wastes allows to d iminish the amount of generated wastes, to reutilize wastes so as to diminish their danger, and to make safe use of the final disposition of those wastes that cannot be reduced. Here we present the principies of chemical wastes management, the analysis of the service I ife of a waste and diverse treatment options (physical, chemical, thermal and biological) for its final disposition

O alisamento químico é o método mais empregado para melhorar a penteabilidade e a estilização de cabelos afro-étnicos. O cabelo é composto basicamente de três partes: cutícula, córtex e medula. O principal constituinte é uma proteína, a queratina. O tratamento com agente alcalino, redutor e/ou oxidante, provoca modificações nessa estrutura, ocasionando danos que podem ocorrer na camada superficial (cutícula) ou em toda a fibra, atingindo inclusive o córtex e modificando as propriedades físico-químicas do cabelo, pois o torna mais quebradiço, frágil, sem brilho, áspero e com mais dificuldade para ser penteado e desembaraçado. O emprego de agentes condicionadores auxilia na melhora dos atributos físicos e sensoriais do cabelo tornando-o mais resistente e facilitando o manuseio. Neste estudo foi preparado um creme-base alisante com tioglicolato de amônio acrescido de agentes condicionadores pré-escolhidos e adicionados no momento do uso. A formulação-base foi submetida ao estudo de estabilidade física por dois meses. Foram realizados testes de: quantificação da perda de proteína equivalente em albumina, empregando-se o método de Lowry modificado por Peterson; penteabilidade e tração de ruptura. Os resultados indicaram que a adição de óleo de jojoba e de silicones, como Lauril PEG/PPG18/18 meticona e Ciclopentasiloxano (e) PEG-12 polímero de dimeticone reticulado, melhoram os atributos físico-químicos e sensoriais das mechas de cabelo afro-étnico, sendo indicado como agentes condicionadores que poderão ser acrescidos à formulação do creme-base alisante. / Chemical hair relaxing is the most common used method to improve combability and styling on afro-ethnic hair. The hair is basically composed of three parts: cuticle, cortex and medulla. The main basic element is a protein, the keratin. The treatment with an alkaline reducing agent and/or an oxidant agent causes modifications in this structure, and related damages that can occur in the superficial layer (cuticle) through ali the fiber, reaching the cortex and modifying the physical-chemical properties of the hair. In that case, the hair becomes more fragile, it has no shine, gets rough and it is very difficulty to comb and to detangle it. Conditioning agents can improve the physical and sensorial attributes of the hair, thus allowing it to become more resistant and making it easier to take care of. In this study a hair straightener cream-base with ammonium thioglycolate was prepared and the selected conditioning agents added at the moment of the use. The straightener cream-base was submitted to the physical stability study for two months. The tests had been carried through: quantification of protein loss of albumine equivalent, using the Lowry method modified by Peterson; the combability and rupture traction. The results have indicated that the addition of Jojoba oil and silicones as Lauryl PEG/PPG-18/18 methicone; and Cyclopentasiloxane (and) PEG-12 dimethicone crosspolymer, improve the physical-chemical and sensorial attributes of the afro-ethnic hair tresses, being indicated as conditioning agents that could be added in a hair straighteners cream formulation to help its care.

Aterros sanitários são a forma mais viável de disposição final dos resíduos sólidos urbanos no Brasil, tanto do ponto de vista técnico quanto econômico. Os antigos lixões estão sendo progressivamente substituídos por aterros bem projetados e operados. Entretanto, os aterros ainda representam risco ambiental devido à liberação de gases e produção de lixiviado (chorume). Os gases podem ser canalizados e queimados ou usados para produção de energia. O tratamento do lixiviado, porém, ainda representa um desafio aos profissionais da área, não tendo ainda sido encontrada uma solução eficaz. As próprias características físico-químicas deste efluente não são bem conhecidas. No presente trabalho buscou-se contribuir para a solução do problema mediante estudos em três frentes: a caracterização detalhada do lixiviado de aterros brasileiros, o estudo da remoção da amônia (o principal poluente presente no lixiviado) por arraste com ar e a importância da força iônica. A compilação de dados referentes a 40 aterros, distribuídos em todas as regiões do país, possibilitou a elaboração de tabelas com as características típicas do lixiviado durante as fases ácida e metanogênica dos aterros. Não se apresentou apenas os valores extremos de cada variável, mas também as faixas mais prováveis de variação. Também foi possível concluir que a fase ácida na maior parte dos casos não dura mais que dois anos nos aterros brasileiros, desde que esses sejam dotados de sistemas de drenagem de base. O estudo do arraste de amônia foi efetuado em torres de 15 cm de diâmetro e 1 m de altura útil, usando-se anéis de polietileno corrugado como material de recheio. Os resultados mostraram que torres aeradas permitem a remoção praticamente total do nitrogênio amoniacal, independentemente de se fazer ou não alcalinização prévia do lixiviado. O volume de ar necessário para remover uma determinada massa de amônia é sempre constante. Somente foi observada nitrificação quando as concentrações de nitrogênio amoniacal ficaram abaixo de 50 mg/L. A elevada força iônica do lixiviado pode ser a responsável pelo fraco desempenho do processo de coagulação-floculação quando aplicado a este efluente. A força iônica é um aspecto pouco estudado no âmbito da engenharia sanitária e ambiental, mas que não pode ser desconsiderada nos estudos acerca do lixiviado. Outros aspectos foram investigados, como o efeito do cloreto na DQO (demanda química de oxigênio) e a possibilidade de desenvolvimento de larvas de insetos nas lagoas de lixiviado. / Sanitary landfills are considered as the most appropriate way for final disposal of municipal solid wastes in Brazil, in the technical and economical point of view. Open dumps have been progressively substituted by well engineered and operated landfills. However, landfills still present environmental risks due to the gas emission and leachate production. Gases can be piped and burnt or used to the electricity production, but the same can not be applied to the leachate. Moreover, the leachate treatment still represents a challenge to the expertise of the area because it was not already found an efficient solution for it. The physical-chemical characteristics of this effluent are not well known yet. This research sought to contribute to the solution of this problem by focusing in three main lines: detailed characterization of the leachate of Brazilian landfills, investigation of the possibilities of ammonia removal (the main pollutant present in the leachate) by air stripping process and evaluation of the importance of the ionic strength. The compilation of data from 40 sanitary landfills, distributed in all the geographic regions of Brazil, allowed the preparation of tables describing the typical characteristics of Brazilian leachates during the acid and methanogenic phases. It was presented not only the extreme values, but also the most probable ranges of variation. It was also possible to conclude that the acid phase lasts no more than 2 years in Brazilian landfills equipped with adequate leachate drainage systems. The study of ammonia air stripping was carried out in towers of 15 cm of diameter and 1 m of packed bed height. Corrugated plastic Raschig rings were used as packing media. Results showed that the aerated towers were able to remove the ammonia almost completely, independently if the pH of leachate was previously increased or not. The volume of air necessary to remove a determined mass of ammonia is always constant. Nitrification occurred only when total ammonia nitrogen concentrations were lower than 50 mg/L. This led to the conclusion that biological systems should not be applied directly to the treatment of raw methanogenic leachate. The high ionic strength of the leachate can be the responsible for the low efficiencies of coagulation-flocculation process applied to this effluent. Even though ionic strength is not usually considered by sanitary and environmental engineering, it should be considered in the studies dealing with leachate. Other aspects were also investigated, as the effect of the chloride in COD (chemical oxygen demand) measurements and the possibility of maggots growth in leachate ponds.

Det här projektet redogör för olika behandlingstekniker för gråvatten och för tillämpningar för olika ändamål inom återanvändning. Syftet är att föreslå en lämplig processdesign för behandling av gråvatten i stadsmiljö, på Loudden, Norra Djurgårdsstaden (NDS). Undersökningen grundar sig på relevant litteratur och på fyra demo-sites där gråvatten behandlas och återanvänds i olika tillämpningar. Gråvattendata samlades in och ett genomsnitt beräknades för att karakterisera gråvatteninflödet. Flödet från gråvattnet beräknades utifrån den dagliga vattenförbrukningen i Sverige om 140 liter/person/dag. Fyra behandlingsprocesser valdes ut. Behandlingsprocesserna kombinerades med förbehandling vilket är standard för att skydda efterföljande process steg. Två av dessa behandlingsprocesser modifierades eftersom de, var och en för sig, inte skulle vara tillräckliga för att minska föroreningar och säkra applikationen för slutanvändaren. De fyra processenheternas prestanda utvärderades utifrån två kriterier:  EU:s kvalitetskriterier  för  återvunnet  vatten  under  klass C samt driftsparametrar. En lista som rangordnar de viktigaste variablerna skapades för att sortera fram det bästa teknikvalet. En utvärderingsprocess visade på designernas lämplighet för den behandling som krävs. "Process Combination 1" valdes på grund av dess robusta prestanda och uppvisade inte några betydande nackdelar. Den består av ett fingaller, en submerged membrane bioreactor och ett kloreringssteg. Processdesignen  innehåller värmeåtervinning och tillämpningar  för  återanvändning  inom processindustri samt bevattning för planteringar inom området. De tekniska och ekonomiska beräkningarna baserades på det karakteriserade gråvattnet och den konstruerade flödet. Investeringskostnaden för den föreslagna processdesignen hamnar på 31 miljoner kronor. Den genererar en årlig inkomst på 5 miljoner kronor och kommer, enligt nuvärdesmetoden och med en ränta på 5 %, att vara fullt betald efter 9 år. / This project presents greywater (GW) treatment techniques and reuse applications for different purposes. The aim is to suggest a suitable process design for treating GW in the urban city environment, Loudden, Norra Djurgårdsstaden (NDS). The research studied relevant literature and four demo sites where GW is treated and reused in various applications. GW data were collected, and an average was used to emulate a GW inflow characteristic. The GW flow was constructed based on estimated daily water consumption in Sweden of approximately 140 liter/person/day. Four treatment process units were selected. The treatment processes units were combined with pre- treatment, a standard treatment to protect the system. Two of these treatment processes were modified because, individually, they would not be sufficient to reduce contaminants and secure the end-user application. The performance of the four process units was evaluated based on two criteria: EU quality criteria for reclaimed water under class C and operating parameters. A list ranking the most critical variables was created to sort out the best process unit. An evaluation process showed the suitability of the designs for the required treatment. "Process Combination 1" was chosen because of its robust performance and did not present any significant drawbacks. It consists of a fine screen, a submerged membrane bioreactor, and a chlorination step. A process design including heat recovery and reuse applications for irrigation of the plantation fiels in the area and process industry was established. The characterized inflow and constructed GW flow were then used for technical and economic calculations. The estimated investment cost for the proposed process design was approximately SEK 31 million. It generates an annual income of SEK 5 million and will, according to the Net Present Value method, with an interest rate of 5%, be fully paid after 9 years.

Studies were conducted to evaluate the impact of landfill leachate discharge on the operation of waste water treatment plants (WWTPs). Two aspects of interferences were found: one is UV quenching substances, which are bio-refractory and able to penetrate the biological treatment processes, consequently interfere the UV disinfection in WWTPs. The other one is organic nitrogen, which can pass the nitrification-denitrification process and contribute to the effluent total nitrogen (TN). Also, treatability study was conducted for landfill gas (LFG) condensate. In a laboratory study, leachate samples were fractionated into humic acids (HA), fulvic acids (FA) and Hydrophilic (Hpi) fractions, the specific UV254 absorbance (SUVA254) of the three fractions follows: HA > FA > Hpi. However, the overall UV254 absorbance of the Hpi fraction was important because there was more hydrophilic organic matter than humic or fulvic acids. It was found that the size distribution of the three fractions follows: HA > FA > Hpi. This indicates that membrane separation following biological treatment is a promising technology for the removal of humic substances from landfill leachates. Leachate samples treated in this manner could usually meet the UV transmittance requirement of the POTWs. Also, nitrogen species in landfill leachates under various stabilization states were investigated. Although the effect of landfill stabilization state on the characteristics of organic matter and ammonia is well documented, there are few investigations into the landfill leachate organic nitrogen under different stabilization stages. Ammonia was found to leach out slower than organic matter and can maintain a constant level within the first a couple of years (< 10 years). The concentration and biodegradability of organic nitrogen were found to decrease with landfill age. A size distribution study showed that most of organic nitrogen in landfill leachates is < 1 kDa. The protein concentration was analyzed and showed a strong correlation with the organic nitrogen. Different slopes of regression curves of untreated and treated leachates indicate that protein is more biodegradable than the other organic nitrogen species in landfill leachates. XAD-8 resin was employed to isolate the hydrophilic fraction of leachate samples, hydrophilic organic nitrogen was found to be more biodegradable/bioavailable than the hydrophobic fractions. Furthermore, biological and physical-chemical treatment methods were applied to a landfill biogas (LFG) condensate to explore the feasible treatment alternatives for organic contaminant and arsenic removal efficiency. Sequencing batch reactor (SBR) showed effectiveness for the degradation of organic matter, even in an environment containing high levels of arsenic. This indicated a relatively low toxicity of organic arsenic as compared to inorganic arsenic. However, for arsenic removal, oxidation-coagulation, including biological oxidation, conventional oxidation and advanced oxidation followed by ferric salt coagulation, and carbon adsorption were not effective for what is believed to be tri-methyl arsenic. Among these, advanced oxidation-coagulation showed the best treatment efficiency (15.1% removal). Only reverse osmosis (RO) could reduce the arsenic concentration to an acceptable level to meet discharge limits. These results implied high stability and low toxicity of organic arsenic. / Ph. D.

O tratamento de águas residuárias industriais, submetido constantemente a cargas de choque, é pouco estudado no Brasil, sendo limitado o grau de conhecimento que se tem no mundo sobre os mecanismos de remoção de disruptores endócrinos nos sistemas de tratamento físico-químicos e biológicos. O presente trabalho traz um estudo de caso, envolvendo uma indústria com uma composição de produtos muito diversificada, com despejos líquidos de unidades isoladas de qualidades diversas e que tem como uma das principais matérias-primas, nonil fenóis, conhecidos disruptores endócrinos. Os mecanismos de remoção de carga orgânica e a avaliação da toxicidade da água residuária ao processo biológico de tratamento foram estudados em escala de laboratório, enquanto que a sua tratabilidade por coagulação, floculação, flotação com ar dissolvido seguido de sistema de lodos ativados, em escala piloto. Avaliou-se, também, a aplicabilidade do tratamento biológico com carvão ativado em pó. A grande variação qualitativa e quantitativa da água residuária bruta requer uma unidade de equalização com tempo de detenção de pelo menos 30 horas. O maior responsável por esta variação de qualidade é o processo da unidade química, cujo efluente é proveniente de lavagens de tanques e reatores. Apesar da reduzida eficiência de remoção de DQO obtida com a coagulação, floculação e flotação com ar dissolvido (20 a 30%), constatou-se que este tratamento é essencial para a redução da toxicidade ao processo biológico. A dosagem de coagulante e o pH ótimos variam conforme a característica do despejo e devem ser determinadas diariamente. No sistema biológico, observou-se uma remoção significativa da DQO do efluente bruto gerado na indústria, não apenas por biodegradação, mas também por volatilização e adsorção. Os testes de bancada evidenciaram remoções de DQO por arraste com ar de 47 a 77 % e por adsorção no lodo biológico, de 42%. Apesar dos constantes choques de carga orgânica e de poluentes tóxicos, conseguiu-se atingir o estado estacionário com variações máximas da concentração de sólidos em suspensão voláteis no tanque de aeração entre 20 e 30%. Neste período, a idade do lodo situou-se em torno de 25 a 30 dias e o tempo de detenção hidráulico foi de 3,8 dias. A eficiência média de remoção de DQO neste período foi de 86%. Os testes com a unidade piloto demonstraram que a utilização de carvão ativado em pó (CAP) produz resultados satisfatórios, comprovando a redução de poluentes tóxicos da água residuária e refletindo em uma significativa melhora na biodegradabilidade do efluente, com aumento da concentração de sólidos em suspensão voláteis no tanque de aeração (de 1380 mg/L para 3820 mg/L) e redução da amplitude de variação da DQO do efluente tratado que passou de 600 a 3200 mgO2/L para o sistema sem CAP para 300 a 600 mgO2/L para o sistema com CAP. Notou-se, também, com a adição de CAP, melhoria na sedimentação do lodo. Pode-se concluir também que o sistema de tratamento atendeu a legislação atual do Estado de São Paulo, com uma remoção média de 80% da DBO5. / Wastewater treatment systems continuously receiving shock loads and the behavior of contaminants under unsteady state conditions are not very well documented in our country, with limited degree of knowledge in the world on the removal of specific pollutants like endocrine disrupting chemicals (EDC) in physical chemical and biological wastewater treatment systems. The present work brings a case study regarding an industry which wastewaters were generated from plants with multiproducts and campaign production with variable composition, and with nonylphenols as one of their raw materials which is known as an endocrine disrupting chemical. The organic load and toxicity removal mechanisms of the wastewater to the biological treatment were studied in bench scale whilst their treatability was evaluated through coagulation, flocculation, dissolved air flotation followed by activated sludge, in pilot scale. The feasibility of the addition of powdered activated carbon to the biological system was also studied. The large qualitative and quantitative variability of the wastewater requires an equalization time of at least 30 hours. The main responsible for this variability in quality is the chemical unit process which wastewaters are originated from reactors and tanks cleanings. Although the low efficiency in COD removal obtained with coagulation, flocculation and dissolved air flotation (20 to 30%), it was found that this process is essential to the toxicity reduction for the biological process. Optimum pH and coagulant dose vary with the wastewater characteristics, and must be determined on a daily basis. On the biological system, it was observed important raw wastewater COD elimination not only through biodegradation, but also through volatilization and adsorption. Bench tests revealed COD elimination of 47 to 77% by air stripping and 42% by adsorption onto the biological sludge. Despite of constant organic and toxic shock loads, it had been possible to reach the steady state during which the maximum variation on the volatile suspended solids concentration was 20 to 30%. During this period, sludge age was around 25 to 30 days, and the hydraulic detention time was 3,8 days. Average efficiency on COD removal in this period was 86%. Tests results with PAC dosage on the pilot plant showed satisfactory, proving the reduction of toxic compounds from the wastewater and resulting in biodegradability improvement. The increase of volatile suspended solids in the aeration tank was from 1380 mg/L to 3820 mg/L, and reduction in the range of variation of remaining treated water COD from 600 to 3200 mgO2/L (system without CAP) down to 300 to 600 mgO2/L (system with CAP). The improvement on the sludge sedimentation with PAC addition was also remarkable. One can also conclude the treatment system attained the current legislation of the State of São Paulo, with 80% BOD5 removal.

Les travaux de recherche effectués lors de cette thèse portent sur l’obtention de nanotubes de carbone ultracourts et leur biofonctionnalisation pour une utilisation comme biomarqueur proche infrarouge. Des dispersions de nanotubes de carbone en milieux aqueux ont été formulées à l’aide de différents tensioactifs. Un traitement chimique oxydant préalable et/ou l’application d’ultrasons aux nanotubes ont permis de réduire leur longueur de façon significative, la sélection des plus courts étant effectuée par ultracentrifugation en gradient de densité. Les différentes fractions sélectionnées à l’issu de ce processus ont été caractérisées par spectroscopie Raman et spectroscopie d’absorption ainsi que par microscopie à force atomique. Il est ainsi montré la sélection de nanotubes d’une longueur inférieure à 20 nm. Nous montrons également leur fonctionnalisation à l’aide d’anticorps monoclonaux et leur visualisation par imagerie photothermique hétérodyne. Des résultats prometteurs ont été obtenus avec la fixation spécifique de nanotubes de carbone ultracourts sur des cellules. Ces travaux ouvrent de nombreuses perspectives en bioimagerie et en particulier l’étude de la plasticité synaptique au sein de neurones vivants. / This thesis reports the achievement of ultrashort carbon nanotubes and their biofunctionalization for applications as near-infrared biomarker. Dispersions of carbon nanotubes in aqueous media have been formulated with various surfactants. Oxidizing chemical treatments combined with the application of ultrasounds allowed significant shortening of the carbon nanotubes. Sorting and selection of the shortest nanotubes was done by density gradient ultracentrifugation. The different fractions selected at the end of this process have been characterized by Raman spectroscopy, UV-vis absorption spectroscopy and atomic force microscopy. Selection of nanotubes of a length below 20 nm is demonstrated. We also show functionalization by antibodies and the visualization of ultrashort functionalized nanotubes by photothermal heterodyne imaging. Promising results were obtained with the specific binding of ultrashort carbon nanotubes to cells. This work open route towards bioimaging applications and in particular towards the study of the synapsis plasticity within alive neurons.

La presente tesis doctoral tiene por objeto tratar de eliminar el fenómeno no deseable de formación de biofouling en diferentes superficies tubulares de intercambiadores de calor, mediante tratamientos físicos y químicos, intentando minimizar el impacto ambiental creado en los efluentes de las instalaciones industriales.El equipo experimental está compuesto por una planta piloto de intercambiadores de calor condensadores dotada de ocho tubos que funcionan como sistemas independientes, donde se controlan los parámetros de presión, temperatura y caudal, que define indirectamente el biofouling depositado en el interior de dichos tubos a través de los valores de resistencia friccional al flujo y resistencia a la transferencia de calor.También ha sido diseñado y construido otra planta piloto o monitor "MCMDID" (monitor combinado de medición directa e indirecta del biofouling) donde se mide en continuo el espesor del biofouling adherido a la superficie de un tubo del mismo material que los ensayados en la planta descrita anteriormente.

Made available in DSpace on 2014-12-17T14:06:55Z (GMT). No. of bitstreams: 1 FranciscoJPF.pdf: 1681554 bytes, checksum: 4238148885bafd3e26a8d8ca7de20466 (MD5) Previous issue date: 2010-08-07 / Nowadays the environmental issues are increasingly highlighted since the future of humanity is dependent on the actions taken by man. Major efforts are being expended in pursuit of knowledge and alternatives to promote sustainable development without compromising the environment. In recent years there has been a marked growth in the development of reinforced composite fiber plants, as an alternative for economic and ecological effects, especially in the substitution of synthetic materials such as reinforcement material in composites. In this current study the chemical- physical or (thermophysics )characteristics of the babassu coconut fiber, derived from the epicarp of the fruit (Orbignyda Phalerata), which the main constituents of the fiber: Klason lignin, insoluble, cellulose, holocellulose, hemicellulose and the content of ash and moisture will be determined. A study was conducted about the superficial modification of the fibers of the epicarp babassu coconut under the influence of chemical treatment by alkalinization, in an aqueous solution of NaOH to 2.5% (m/v) and to 5.0% to improve the compatibility matrix / reinforcement composite with epoxy matrix. The results of the changes occurred in staple fibers through the use of the techniques of thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The results found on thermal analysis on samples of fiber without chemical treatment (alkalinities), and on fiber samples treated by alkalinization show that the proposed chemical treatment increases the thermal stability of the fibers and provides a growth of the surface of area fibers, parameters that enhance adhesion fiber / composite. The findings were evaluated and compared with published results from other vegetable fibers, showing that the use of babassu coconut fibers has technical and economic potential for its use as reinforcement in composites / Atualmente as quest?es ambientais ganham destaque cada vez mais acentuado, j? que o futuro da humanidade est? dependente das a??es tomadas hoje pelo homem. Grandes esfor?os est?o sendo despendidos na busca de conhecimentos e solu??es alternativas sustent?veis que promova o desenvolvimento sem comprometimento do meio ambiente. Nos ?ltimos anos tem havido um crescimento acentuado no desenvolvimento de comp?sitos refor?ados por fibras vegetais, como uma alternativa econ?mica e ecol?gica, principalmente, na substitui??o de materiais sint?ticos, como material de refor?o em comp?sitos. No presente trabalho foram analisadas as caracter?sticas qu?mico-f?sicas de fibra oriundas do epicarpo do coco baba?u (Orbignyda Phalerata), sendo determinados os principais teores dos constituintes da fibra: lignina Klason insol?vel, celulose, holocelulose, hemicelulose e os teores de cinzas e de umidade. Foi realizado um estudo da modifica??o superficial das fibras do epicarpo do coco baba?u sob efeito de tratamento qu?mico por alcaliniza??o, em solu??o aquosa de NaOH a 2,5% (m/v) e a 5,0% (m/v), visando melhorar a compatibiliza??o matriz/refor?o em comp?sito com a matriz de ep?xi. Os resultados das modifica??es ocorridas nas fibras foram estudados atrav?s de t?cnicas de termogravimetria (TG) e de calorimetria explorat?ria diferencial (DSC). Os resultados encontrados nas an?lises t?rmicas em amostras de fibras sem tratamento qu?mico e em amostras de fibras tratadas por alcaliniza??o mostram que o tratamento qu?mico proposto aumentou a estabilidade t?rmica das fibras e proporcionou um crescimento na ?rea superficial das fibras, par?metros que melhoram a ades?o fibra/comp?sito. Os resultados obtidos foram avaliados e comparados com resultados publicados de outras fibras vegetais, mostrando que a utiliza??o das fibras de coco baba?u tem potencialidades t?cnicas e econ?micas para o seu uso como refor?o de comp?sitos