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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Monitoring of polyelectrolytes in waters, process streams and the environment

Higgins, Julie Marie January 1999 (has links)
No description available.
2

Development of methods for the determination of some trace substances in water

Arryanto, Yateman January 1990 (has links)
No description available.
3

AvaliaÃÃo do Desaguamento de ResÃduos de Esgotamento de CaminhÃo Limpa-Fossas AtravÃs de TÃcnica de DesÃgue em GeotÃxtil e AplicaÃÃo de PolÃmeros / Evaluation of Dewatering Waste Exhaustion Cleans Septic Truck Through Technical outflow in Geotextile and Application of Polymers

Edlene Sales de Paula 01 October 2012 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O lodo da fossa sÃptica deve ser removido periodicamente. Esse material sedimentado e jà isento de material graxo à produto de digestÃes anaerÃbias transformados em compostos mais simples. Geralmente sÃo removidos por caminhÃo limpa fossa e dispostos nas estaÃÃes de tratamento de esgoto, quando estas existem. O lodo, apesar de ser extremamente rico em sÃlidos, possui teor de Ãgua considerÃvel que pode ser removido por tÃcnicas de desÃgÃe. De um modo geral, o desaguamento à utilizado para aumentar o teor de sÃlidos do lodo reduzindo seu volume. Esse material depois de estabilizado, por exemplo, atravÃs da compostagem, poderà ser aplicado no solo como adubo agrÃcola apÃs tratamento e avaliaÃÃo por meio de ensaios de caracterizaÃÃo e toxicidade. Dessa forma, o lodo de fossa sÃptica pode ter uma destinaÃÃo ambientalmente mais nobre, inclusive, diminui a quantidade de material sÃlido nas estaÃÃes de tratamento de esgoto e aumenta a vida Ãtil das lagoas devido a menor freqÃÃncia de dragagem. A proposta do trabalho à desenvolver uma metodologia de desÃgÃe do lodo atravÃs de geotÃxtil para avaliar a aplicaÃÃo de polÃmeros orgÃnicos e poliacrilamidas por meio de teste de jarro e ensaios de turbidez com a finalidade de estabelecer o tipo do polÃmero e suas concentraÃÃes que apresentem melhor eficiÃncia na reduÃÃo do teor de sÃlidos. A funÃÃo do polÃmero à favorecer a agregaÃÃo das partÃculas de sÃlidos e formaÃÃo de flocos atravÃs da desestabilizaÃÃo das forÃas quÃmicas ou fÃsicas atuantes nas partÃculas coloidais e no material particulado em suspensÃo imerso em meio lÃquido. Para avaliaÃÃo do geotÃxtil foram realizados ensaios de cone e saco suspenso. Nos testes de jarro foi verificado que os polÃmeros estudados apresentaram Ãtimos Ãndices de remoÃÃo de turbidez (82,0% - 99,8%) com aplicaÃÃes variando as concentraÃÃes de polÃmero de 14 a 275mg/L. Nos ensaios de cone as remoÃÃes variaram de 46,3% - 56,0%. Finalmente nos ensaios de saco suspenso as remoÃÃes variaram de 98,0% - 99,0%. Estas concentraÃÃes podem sofrer alteraÃÃes de acordo com as caracterÃsticas do lodo amostrado. / The sludge from the septic tank must be removed periodically. This material has been consolidated and free fatty material is the product of anaerobic digestion transformed into simpler compounds. Are usually removed by truck clean sump and disposed in sewage treatment plants, where these exist. The sludge, despite being extremely rich in solids, has a considerable content of water which can be removed by techniques outflow. In general, it is used for dewatering to increase the solids content of the slurry reducing its volume. This material is stabilized after, for example, by composting can be applied to agricultural land as a fertilizer after treatment and assessment by testing for characterization and toxicity. Thus, the septic tank sludge disposal can have a more environmentally noble even decreases the amount of solid material in sewage treatment plants and increases the life of the ponds due to lower frequency of dredging. The purpose of this study is to develop a sludge outflow through the geotextile to evaluate the application of organic polymers and polyacrylamides through jar test and turbidity tests in order to establish the type of polymer and their concentrations which have improved efficiency reducing the solids content. The function of the polymer is to promote the aggregation of solid particles and flocculation destabilization by chemical or physical forces acting on the particles in the colloidal and suspended particulate material immersed in a liquid medium. For evaluation of geotextile tests were performed cone and bag drop. In jar tests it was found that the polymers studied have optimum turbidity removal rates (82.0% - 99.8%) applications with varying concentrations of polymer from 14 to 275mg / L. In tests of the cone removals ranged from 46.3% - 56.0%. Finally assays bag suspended removals ranged from 98.0% - 99.0%. These concentrations may change according to the characteristics of the sludge sampled.
4

Farmakokinetika intramuskulárně aplikovaných termoresponsivních polyakrylamidů / Pharmacokinetics of Intramuscularly Administered Thermoresponsive Polyacrylamides

Groborz, Ondřej January 2021 (has links)
6 Pharmacokinetics of Intramuscularly Administered Thermoresponsive Polyacrylamides Author: Ondřej Groborz Supervisor: doc. Mgr. Martin Hrubý, Ph.D., DSc. Institute of Macromolecular Chemistry, Czech Academy of Sciences Advisers: Ing. Pavel Švec RNDr. Lenka Loukotová, PhD. Abstract Polymer solutions with lower critical solution temperature (LCST) undergo a phase separation when heated above their cloud point temperature (TCP). These thermoresponsive polymers have numerous promising medicinal applications, such as in situ depot-forming radiotherapy (brachytherapy), controlled drug-release, immuno-radiotherapy, injectable thermogelling for tissue engineering and cell culture and magnetic resonance imaging (MRI), among others. Yet, despite extensive research on medicinal applications of thermoresponsive polymers, their fate after their administration remains largely unknown. Thus, in our study, we synthesized and thoroughly characterized four different thermoresponsive polyacrylamides, namely poly(N-(2,2-difluoroethyl)acrylamide), poly(N- isopropylacrylamide), poly(N,N-diethylacrylamide) and poly(N-acryloylpyrrolidine) under physiologically relevant conditions. Subsequently, we determined their biodistribution kinetics in mice and proposed a data-based pharmacological model to describe their in vivo behaviour,...
5

POLYMERIC BONDED PHASES FOR PROTEIN EXTRACTION AND INTACT GLYCOPROTEIN ANALYSIS

Edwin Jhovany Alzate Rodriguez (7010366) 12 August 2019 (has links)
Polymer brushes are extremely versatile materials, as monomer choice allows the user to design a material with the desired physiochemical properties. Given the wide variety in monomer functionality, polymers can be fine-tuned for a specific application. In this work, polymer brushes bound to a silica support are designed and utilized to enhance performance of protein extraction and chromatographic separations. <br> The effectiveness of an analytical method is strongly affected by matrix composition, however, the presence of species other than the target analyte is usually unavoidable. An excellent technique will be able to identify and/or quantify the analyte even when its concentration is low compared with interfering molecules. Protein analysis is particularly challenging, since many proteins of clinical and scientific significance are present in complicated matrices such as plasma or cell lysates. <br>A common method to specifically separate a protein from a complicated matrix is solid phase extraction. In this method, a species (such as an antibody) with high specificity towards the target is immobilized onto a solid substrate (commonly beads or small particles for greater surface area). Next, the target is collected onto the surface, bound by the species. The solid substrate is rinsed of the liquid matrix, before elution of the target. Only the active species should interact with the analyte, and the surface should be otherwise inactive. However, nonspecific interactions lead to binding/adsorption of undesirable compounds. Therefore, an optimal substrate for protein extraction must be 1) easily and completely removable from the liquid phase, 2) have a high concentration of active sites for specific binding, and 3) exhibit low nonspecific binding. As part of this work, commercial magnetic particles were coated with a nonporous silica layer that tolerates the acid bath and silane coating necessary to attach a polymer layer. On the silane coating, a polymer layer was covalently bound; this layer contains epoxide active groups for immobilizing antibodies. These antibodies bind to the target molecule with high specificity, and low nonspecific binding. Obtained particles were evaluated for protein extraction, where antibodies as well as specifically engineered drug compounds were successfully bound to the particle surface.<br>Glycosylation influences several physiopathological processes in proteins. Glycans can act as receptors, modify protein solubility, and participate in folding conformation. Altered glycosylation is a common feature in tumorous cells. As such, many modifications in glycoproteins have been related to cancer, including increased branching of N-glycans or augmented units of sialic acid. Therefore, characterization of glycoproteins is important not only as a diagnostic tool, but also to monitor patients’ response to treatment. Furthermore, it is important in the growing field of monoclonal antibodies as drug carriers. <br>Among different methods used for glycosylation analysis, Hydrophilic Interaction Liquid Chromatography (HILIC) has showed important advantages over time-consuming digestion-MS based techniques. An adequate HILIC stationary phase can be used to rapidly differentiate glycoforms present in a sample. In the second part of this work, a polymer brush based bonded phase was developed as a HILIC stationary phase. The new polymer improved the separation of a model glycoprotein compared with a commercial HILIC column, while also exhibiting enhanced stability over a previous bonded phase synthetized in our group.<br><br>
6

Design of mechanoresponsive surfaces and materials / Conception des surfaces et des matériaux mécano-répondants

Rios Neyra, César 26 September 2013 (has links)
Le but de ma thèse a été de concevoir des matériaux chimio-mécano répondants, des matériaux capables de permettre une transformation chimique réversible lorsqu’ils sont soumis à un stress mécanique. Tous les systèmes conçus ont été développés sur des substrats en silicone. Une première approche a consisté à créer des surfaces à sites cryptiques où une biotine est enfouie dans des brosses de chaines de poly(éthylène glycol). Le système streptavidine/biotine a été utilisé comme modèle. Ces surfaces sont anti-adsorbantes à la streptavidine sauf lorsqu’elles sont étirées à 50% où la biotine est reconnue mais les surfaces sont non réversibles. Dans une seconde approche, nous avons modifiés la surface du silicone par adsorption d’une multicouche de polyélectrolytes. Cette stratégie est basée sur la réticulation covalente du film par l’enzyme β-galactosidase modifiée. Nous sommes ainsi parvenus à créer une surface présentant une activité catalytique modulable par l’étirement mécanique, et ce, d’une façon partiellement réversible. Ce travail représente le premier exemple d’un système où une contrainte mécanique imposée à un matériau permet la déformation conformationnelle d’une enzyme et ainsi la diminution de l’activité catalytique. Dans une dernière approche, nous avons conçu un système mixte composé d’un substrat de silicone sur lequel un gel de polyacrylamide est greffée de façon covalente. Des enzymes ou des mécanophores pourront ainsi être inclus dans le réseau polymérique du gel de polyacrylamide et être étirés. Nous sommes parvenus à préparer de tels systèmes où l’hydrogel reste solidaire du film de silicone, sans apparition de craquelures jusqu’à 50%d’étirement. / The goal of my PhD was to develop new routes to design chemo-mechanoresponsive materials, materials that respond chemically to a mechanical stress, in a reversible way. All the systems designed during my PhD thesis were based on the functionalization of silicone sheets. First we created cryptic site surfaces by embedding biotin ligands into PEG brushes. The couple streptavidin/biotin was used as a model system. At rest, the surface so-prepared was antifouling and biotin ligands were specifically recognized by the streptavidin when the surface was stretched at 50%. Unfortunately, in this first approach, the mechanosensitive surface did not lead to a reversible process. In a second approach, we modified the silicone surface by using the polyelectrolyte multilayer (PEM) film deposition. This strategy was based on the covalent cross-linking of modified enzyme, the β-galactosidase, into the PEM. We succeeded in modulating the enzyme activity in the film under stretching and this approach appears as partially reversible under stretching/unstretching cycles. This work represents the first reported system where enzymatic activity can be modulated by stretching due to modulation of the enzyme conformation. In a last approach, we also designed a mixed system consisting of a silicone sheet onto which a polyacrylamide hydrogel is covalentlyattached with the goal to create a stretchable gel into which one can covalently attach enzymes or chemical mechanophores. These enzymes or mechanophores can thus be put under mechanical stress. We succeeded in creating a system that can be stretched up to 50% without detachment of the gel from the silicone and without inducing cracks in the gel.

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