• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 6
  • 6
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 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

Híbrido inorgânico-orgânico formado por nanozeólita L e ftalocianina de silício com potencial aplicação na descontaminação de água através da luz solar / Inorganic-organic hybrid based on nanozeolite L and silicon phthalocyanine with potential application in water decontamination by sunlight

Leitão, Renan Camurça Fernandes 18 August 2015 (has links)
Um híbrido inorgânico-orgânico formado por nanozeólita L (nZeol-L) funcionalizada em sua superfície com ftalocianina de silício (SiPC) foi investigado visando uma potencial aplicação para descontaminação de água, via geração de oxigênio singleto (1O2), que por sua vez é citotóxico para sistemas biológicos. Ftalocianinas são corantes orgânicos que possuem comprovada eficiência na geração de oxigênio singleto. No entanto, estes corantes possuem tendência para formar agregados, o que torna ineficiente a formação de 1O2. nZeol-L constitui-se como um material apropriado para suportar SiPC covalentemente em sua superfície com o objetivo de prevenir o processo de agregação, mantendo assim as propriedades fotofísicas dos monômeros do corante. Neste estudo, um híbrido foi preparado visando a fotoinativação da bactéria E. coli (facilmente encontrada em água contaminada) através da luz solar natural. A superfície da nanozeólita L foi funcionalizada com o fotossensitizador (SiPC) e com moléculas de 3-aminopropiltrietoxisilano (APTES) para criar cargas positivas na superfície do material, tornando o híbrido capaz de interagir eletrostaticamente com a superfície negativa das bactérias. Testes de viabilidade celular foram realizados com dois tipos de células: BALB/c 3T3 clone A31 e células de E. coli suspensos em uma solução de PBS (pH 7,4) com a presença do híbrido (nZeol-SiPC/APTES). Foi verificada uma alta eficiência de nZeol-SiPC/APTES em induzir a morte de ambas as células em grande quantidade e dentro de um curto período de tempo. Estes resultados indicam que o nanomaterial (nZeol-SiPC/APTES) possui uma potencial aplicação para a descontaminação de água, quando ativado pela luz do sol. / An inorganic-organic hybrid based on nanozeolite L (nZeol-L) surface-functionalized with silicon phthalocyanine (SiPC) has been investigated aiming its future use in water decontamination by singlet oxygen generation, which is cytotoxic for biological systems. Phthalocyanines are dyes with great efficacy in singlet oxygen generation. However, these dyes have tendency to form aggregates, and hence, the formation of this reactive species of molecular oxygen turns to be inefficient. nZeol-L is an appropriate material to covalently support SiPC on its surface to avoid the aggregation process, thereby maintaining the photophysical properties of the monomer. In this study, a hybrid was prepared aiming the photoinactivation of E. coli bacteria (which is easily found in contaminated water) by natural sunlight. The nanozeolite L surface was functionalized with the photosensitizer (SiPC) and then with 3-aminopropyltriethoxysilane (APTES) molecules to create a positive charge on the material surface, enabling the hybrid to interact with the negative charge to the E. coli bacteria. Cell viability tests were performed with two types of cells: BALB/c 3T3 clone A31 and E. coli cells suspended in PBS solution (pH 7.4) in the presence of the hybrid (here called nZeol-SiPC/APTES). It was verified that nZeol-SiPC/APTES gives rise to the death of the both cells in a large quantity and within a short time interval. These results indicate that the nanomaterial (nZeol-SiPC/APTES) has potential application for water decontamination when activated by sunlight.
2

Híbrido inorgânico-orgânico formado por nanozeólita L e ftalocianina de silício com potencial aplicação na descontaminação de água através da luz solar / Inorganic-organic hybrid based on nanozeolite L and silicon phthalocyanine with potential application in water decontamination by sunlight

Renan Camurça Fernandes Leitão 18 August 2015 (has links)
Um híbrido inorgânico-orgânico formado por nanozeólita L (nZeol-L) funcionalizada em sua superfície com ftalocianina de silício (SiPC) foi investigado visando uma potencial aplicação para descontaminação de água, via geração de oxigênio singleto (1O2), que por sua vez é citotóxico para sistemas biológicos. Ftalocianinas são corantes orgânicos que possuem comprovada eficiência na geração de oxigênio singleto. No entanto, estes corantes possuem tendência para formar agregados, o que torna ineficiente a formação de 1O2. nZeol-L constitui-se como um material apropriado para suportar SiPC covalentemente em sua superfície com o objetivo de prevenir o processo de agregação, mantendo assim as propriedades fotofísicas dos monômeros do corante. Neste estudo, um híbrido foi preparado visando a fotoinativação da bactéria E. coli (facilmente encontrada em água contaminada) através da luz solar natural. A superfície da nanozeólita L foi funcionalizada com o fotossensitizador (SiPC) e com moléculas de 3-aminopropiltrietoxisilano (APTES) para criar cargas positivas na superfície do material, tornando o híbrido capaz de interagir eletrostaticamente com a superfície negativa das bactérias. Testes de viabilidade celular foram realizados com dois tipos de células: BALB/c 3T3 clone A31 e células de E. coli suspensos em uma solução de PBS (pH 7,4) com a presença do híbrido (nZeol-SiPC/APTES). Foi verificada uma alta eficiência de nZeol-SiPC/APTES em induzir a morte de ambas as células em grande quantidade e dentro de um curto período de tempo. Estes resultados indicam que o nanomaterial (nZeol-SiPC/APTES) possui uma potencial aplicação para a descontaminação de água, quando ativado pela luz do sol. / An inorganic-organic hybrid based on nanozeolite L (nZeol-L) surface-functionalized with silicon phthalocyanine (SiPC) has been investigated aiming its future use in water decontamination by singlet oxygen generation, which is cytotoxic for biological systems. Phthalocyanines are dyes with great efficacy in singlet oxygen generation. However, these dyes have tendency to form aggregates, and hence, the formation of this reactive species of molecular oxygen turns to be inefficient. nZeol-L is an appropriate material to covalently support SiPC on its surface to avoid the aggregation process, thereby maintaining the photophysical properties of the monomer. In this study, a hybrid was prepared aiming the photoinactivation of E. coli bacteria (which is easily found in contaminated water) by natural sunlight. The nanozeolite L surface was functionalized with the photosensitizer (SiPC) and then with 3-aminopropyltriethoxysilane (APTES) molecules to create a positive charge on the material surface, enabling the hybrid to interact with the negative charge to the E. coli bacteria. Cell viability tests were performed with two types of cells: BALB/c 3T3 clone A31 and E. coli cells suspended in PBS solution (pH 7.4) in the presence of the hybrid (here called nZeol-SiPC/APTES). It was verified that nZeol-SiPC/APTES gives rise to the death of the both cells in a large quantity and within a short time interval. These results indicate that the nanomaterial (nZeol-SiPC/APTES) has potential application for water decontamination when activated by sunlight.
3

Mécanismes de capture de nanoparticules magnétiques : application à la purification de l'eau / Mechanisms of magnetic nanoparticles capture : application to water purification

Magnet, Cécilia 20 December 2013 (has links)
La séparation magnétique est utilisée dans le domaine de la purification de l’eau. Des nanoparticules magnétiques fonctionnalisées ou nues sont en charge de capter un polluant ciblé puis sont enlevées de l’eau par l’application d’un champ magnétique. Nous avons montré que l’utilisation d’un ferrofluide aqueux classique constitué de nanoparticules d’oxyde de fer recouvertes par une double couche de surfactant d’acide oléique permet une adsorption efficace des cations métalliques (ion nickel Ni2+) puis leur enlèvement en utilisant des microparticules magnétiques. Nous avons montré que des interactions magnétiques suffisamment fortes entre les nanoparticules induisent une transition de phase colloïdale. Il existe trois régimes de captage qui dépendent de deux paramètres, le premier paramètre est lié à l’intensité du champ magnétique et le second est la concentration en nanoparticules. En présence de l’écoulement de la suspension des nanoparticules, le captage des nanoparticules est toujours régi par la concentration en nanoparticules et également par le nombre de Mason. Nous avons mené une expérience de captage des nanoparticules par un milieu poreux. L’efficacité de filtration est liée à la compétition entre les forces hydrodynamiques et magnétiques ainsi que de la séparation de phase au sein de la suspension. Les théories développées lors de ce travail sont en accord raisonnable avec les résultats expérimentaux et montrent l’augmentation de l’efficacité de captage des nanoparticules avec l’augmentation de l’intensité du champ magnétique et de la concentration en nanoparticules ainsi que la diminution de l’efficacité de captage avec l’augmentation du nombre de Mason. / Magnetic separation is used in the domain of water purification. In these systems, functionalized or bare magnetic nanoparticles are used to capture a target pollutant then they are extracted from water by an applied magnetic field. We have shown that a classical aqueous ferrofluid composed by iron oxide nanoparticles covered with an oleic acid double layer allows efficient adsorption of metallic cations (nickel ion Ni2+) followed by nanoparticle extraction with the help of magnetic microparticles. We have shown that strong enough magnetic interactions between nanoparticles can induce a colloidal phase transition. There exists three capture regimes which depend on two parameters, the first one is related to the magnetic field intensity and the second is the nanoparticle concentration. In the presence of the flow of nanoparticle suspension, the nanoparticle capture is always governed by the nanoparticle concentration and also by Mason number. We have carried out an experiment on nanoparticle capture in a porous medium. The filtration efficiency is related to the competition between the hydrodynamic and magnetic forces, as well as to the phase separation in the suspension bulk. The theories developed in the frames of this work show a reasonable agreement with the experimental results. They predict an increase of the capture efficiency with an increase of the magnetic field intensity and the nanoparticle concentration as well as a decrease of the capture efficiency with the growth of the Mason number.
4

Electrospun Fibers for Energy, Electronic, and Environmental Applications

Bedford, Nicholas M. January 2011 (has links)
No description available.
5

Prostředky dekontaminace osob a techniky v zóně havarijního plánování / Means and Decontamination of People and Technique in Area of Emergency Planning

NIMANSKÝ, Jiří January 2018 (has links)
There are two nuclear power plants in the Czech Republic for which measures to protect the population are proposed in the case of a radiation accident. This diploma thesis deals with one of them by decontamination of persons and techniques in the emergency planning zone. The theoretical part of the diploma thesis focuses mainly on knowledge and concepts in the field of ionizing radiation, radiation protection and emergency planning. The main objective was to analyze, compare and evaluate the existing and newly introduced decontamination means of persons and equipment of the Fire Rescue Service of the Czech Republic and the Army of the Czech Republic. For this purpose, eight decontamination devices have been selected for use in a radiation accident. One of the partial objectives is also to compare the decontamination methods and procedures of both components. The quantitative processing of the parameters studied was used to compare, and a multi-criteria decision-making method was used to obtain the results, using the scoring method. In order to obtain data and information, searches of available publications, methodological sheets and instructions for decontamination equipment were carried out. All information has been consulted with chemical experts from the Fire Brigade of the Czech Republic and chemical units of the Army of the Czech Republic. The results of the comparison showed that the decontamination facilities of the members of the Fire Rescue Service of the Czech Republic are more suitable for use in the radiation accident. Their main advantages are a more effective solution for wound decontamination and a system for capturing and collecting contaminated water. However, the Army of the Czech Republic would be able to do the same work after the partial modifications. The decontamination equipment for solving the radiation accident is constantly being refined. An example is the Portable Frame Gamma Detector. This allows you to speed up the decontamination process and saves the forces and resources deployed to deal with an emergency.
6

Green Graphene Development for Removal of Bisphenol-S from Water

Alibrahim, Ismail Salem 13 July 2022 (has links)
No description available.

Page generated in 0.1506 seconds