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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

Control of surface interactions with ultra-violet/ozone modification at polystyrene surface

Liang, He January 2014 (has links)
Surface interactions and reactivity are of critical importance in current biomedical technologies, for example, satisfactory cell attachment and long term viability are essential for optimal in vitro tissue culture and for successful implantation and stability of cardiovascular medical implants such as stents and grafts. To achieve this, the control of fundamental forces and the resulting molecular interactions between the relevant surface and absorbing or adhering species in the physiological system is compulsory. This work utilised the surface modification technique of Ultra-Violet/ Ozone to improve the polystyrene biocompatibility by oxidising the surface with additional polar oxygen functional groups without damaging the surface bulk property. UV/Ozone treatment utilised throughout this study produced controllable oxygen functional groups and led to an increase in surface atomic oxygen level to 41% on unwashed and 35% on washed polystyrene surfaces, washing resulted in the removal of low molecular weight oxidised materials. Surface energy was increased by the addition of oxygen functional groups with the combination of alcohol (C-OR), carbonyl (C=O) and carboxyl (O-C=O); Saturation state was reached after 300s of UV/Ozone treatment where no more oxygen functionalities were incorporated to the surface. Moreover, UV/ozone treatment did not show an effect on the surface roughness studied by atomic force microscopy. The biological responses of human endothelial umbilical vein cells (HUVECs) were studied at the different level of UV/Ozone treated surfaces. HUVEC adhesion, proliferation and migration were significantly improved by the treatment compared to untreated and tissue cultures plastics (TCPs). Among the levels of UV/ozone treatment studied, 120s and 180s were found to be the most effective and HUVEC proliferation did not seem to be affected by the high level of oxygen. Similarly, the surface oxygen level did not affect the migration over UV/Ozone treated over 60s. Hypoxic condition significantly increased HUVECs migration on UV/Ozone treated, TCPs and untreated surfaces compared to normoxia, the oxygen rich surface did not favour to HUVECs that underwent regulatory process to enable the cells to increase migration. Under laminar flow conditions, HUVECs did not only grow, proliferate and migrate but also showed standard responses on UV/Ozone treated polystyrene surface. A decrease in cell size was observed at all shear stress intensities studied (1 dyn/cm2, 9 dyn/cm2 and 25 dyn/cm2) and the decrease was more obvious at higher shear stress. High shear stress intensity also induced high cell turnovers, which may be related to air bubbles induced at high flow rate. The overall findings of this study clearly illustrate that UV/Ozone surface treatment can be applied on polystyrene to improve human endothelial cells functionalities in term of adhesion, proliferation and migration in both static and laminar flow environment.
2

Processo de ozon?lise aplicado ao aproveitamento tecnol?gico de res?suos de coco verde / Ozonolysis process applied to the technological use of green coconut waste

Gurgel, Monique de Moura 29 April 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-21T17:26:15Z No. of bitstreams: 1 2016 - Monique de Moura Gurgel.pdf: 5504454 bytes, checksum: 56c93476cae66a9ba7cfc9cad8b26016 (MD5) / Made available in DSpace on 2017-03-21T17:26:15Z (GMT). No. of bitstreams: 1 2016 - Monique de Moura Gurgel.pdf: 5504454 bytes, checksum: 56c93476cae66a9ba7cfc9cad8b26016 (MD5) Previous issue date: 2016-04-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The chemical analysis and structural analyzes of tropical biomass products has become a potential interest for the production of biofuels. Residues from coconut is promising because it doesn`t compete with the food industry and it can be transformed into a higher product added value due the lignocellulosic origin. Green coconuts had been separated between fiber and parenchyma following by anatomical characterization which it could better be understood and visualized the effect of pretreatment delignification; ozonolysis, with the chemical and compositional changes in the cell wall. To access the carbohydrates, lignin must be removed, thus it had been explored the changes induced by ozone under pH conditions; with addition of acetic acid and sodium hydroxide, and treatment time in milli-Q water. The ozonolysis was carried out at pH 3, 5 and 8 for 2; 4 and 6 hours at 25 ? C. Analyses were performed before and after the ozonolysis reaction to investigate the change of polysaccharides and lignin with the following techniques: SEM, Py-GC/MS, HPLC, FT-IR and TGA. With Scanning electron microscope and infrared spectroscopy, it was possible to observe the degradation of structural components of the fibers, in the form of "spring", from 4 hours of oxidation and changes in the intensities of the bands. According to the Py-GC/MS results, compounds resulting from lignin had been identified and stablished S/G ratio as 0,73. With a lignin Klason content of 26.28% from green coconut fiber and 25.45% from parenchyma. The best conditions of ozone treatment were determined to be the fiber with no addition of reagents for 4 hours under oxidation as determined by the increase of glucose content in the hydrolysate to 45.96 % after acid hydrolysis of ozone treated fibers. / An?lises qu?micas e estruturais dos produtos de biomassa tropical tem se tornado um potencial interesse para produ??o de novos produtos que agreguem valores sustent?veis, dentre eles, os biocombust?veis. Res?duos de coco se tornam promissores pois n?o competem com a ind?stria aliment?cia e podem ser transformados em um produto de maior valor agregado visto serem de origem lignocelul?sica. Nesse contexto, os cocos verdes foram separados entre fibra e par?nquima e por conseguinte, caracterizados a n?vel anat?mico para que melhor pudesse ser compreendido a rela??o do tratamento utilizado para deslignifica??o; no caso, a ozon?lise, assim como as altera??es qu?micas e composicionais da parede celular. Para acessar os carboidratos, a lignina precisa ser removida, portanto foi explorado as mudan?as induzidas pelo oz?nio sob condi??es de pH; atrav?s adi??o de ?cido ac?tico e hidr?xido de s?dio, e tempo. O tratamento com oz?nio em solu??o de ?gua biodeionizada foi conduzido em pH 3, 5 e 8 por 2, 4 e 6 horas a temperatura de 25?C. As an?lises foram realizadas com amostras anteriores e posteriores ? rea??o de ozon?lise, investigando as altera??es dos polissacar?deos e da lignina com as seguintes t?cnicas: MEV, Pi-GC/MS, CLAE, FT-IR e TGA. De acordo com a Microscospia eletr?nica de varredura e Espectroscopia de infravermelho, foi poss?vel observar a degrada??o dos componentes estruturais das fibras, em forma de ?mola?, a partir de 4 horas de oxida??o e altera??es nas intensidades das bandas respecivamente. De acordo com a Pi-GC/MS, os derivados da lignina foram identificados e estabelecido uma rela??o S/G de 0,73 para fibra. O teor de lignina de Klason foi de 26,28% para a fibra e 25,45% para o par?nquima. Em visto disso, chegou-se a conclus?o que a melhor condi??o de tratamento com oz?nio foi obtido com as fibras sem adi??o de reagente sob 4 horas de exposi??o ao agente oxidante, determinado pelo aumento do teor de glicose a 45,96%.
3

Tratamento de efluentes gredaos pela lavagem de aeronaves agrícolas e pelo descarte das aplicações aéreas de agrotóxicos / Treatment system of wastewater generated by washing and disposal of aerial applications of pesticides

Furtado, Ricardo Dourado January 2012 (has links)
Esta tese tem como objetivo analisar a eficiência de um sistema de tratamento de efluentes gerados na lavagem de aeronaves agrícolas e pelo descarte dos agrotóxicos não utilizados na aplicação aérea. O sistema é composto por piso de lavagem impermeabilizado, tanque de decantação, sistema de oxidação por ozônio e leito de volatilização. Esta pesquisa foi dividida em duas fases. Na Fase 1, acompanhou-se as campanhas de aplicações aéreas, coletando-se dados como: quantidade de efluente gerado, de água consumida e os agrotóxicos utilizados a fim de gerar informações para o experimento proposto e conhecer o impacto ambiental da aplicação aérea de agrotóxicos. O consumo médio de água foi de 112,8L e a produção de efluente foi de 132,8L, por lavagem. Na Fase 2, realizaram-se análises físicas e químicas, da concentração e da carga dos princípios-ativos dos agrotóxicos do efluente, nas etapas do sistema de tratamento. O efluente foi submetido a duas taxas distintas de ozônio, 1,0 e 2,0 g de O3/hora, para avaliar o grau de degradação pela diferença de concentração.O sistema reduziu as concentrações de Piraclostrobina do efluente em 97%, Epoconazole 98,1%, Imazetapir 92,4%, Imazapic 91,8% e Flufenoxuron 82,8%, para taxa de 1,0 g de O3/hora; e para 2,0 g reduziu a concentração de Piraclostrobina em 85,1%, de Epoconazole 97,1%, Imazetapir 97,1%, Imazapic 94,7% e Flufenoxuron 86,0 %. Com a redução da carga a partir da Amostra 1 (sem o efeito do C.O.), constatou-se redução de Piraclostrobina em 90,8%, de Epoconazole 73,0%, Imazetapir 69,1%, Imazapic 71,5% e Flufenoxuron 44,8%, para taxa de 1,0 g de O3/hora ; e para 2,0 g houve redução de Piraclostrobina em 50,3%, de Epoconazole 59,3%, Imazetapir 80,7%, Imazapic 82,4% e Flufenoxuron 63,2. A Demanda Química de Oxigênio do efluente dos agrotóxicos após completar o tratamento apresentou valores acima do permitido para lançamento no meio ambiente, pela legislação ambiental, principalmente a Resolução CONSEMA 128/2006 que limita em 400 mg de O2/L para vazões inferiores a 20 m3/dia. O Cascade com DQO igual a 2.165,00 mg de O2/L, o Opera 4.191 mg de O2/L, e o Only com 668,50 mg de O2/L. O sistema de tratamento funcionou diminuindo a concentração e a carga dos agrotóxicos e reteve o produto final do tratamento, atendendo as legislações agrícolas e ambientais, e as características econômicas e técnicas das empresas de aviação agrícola. / This thesis aims to analyze the efficiency of a system for treating wastewater generated by the washing of agricultural aircraft and the disposal of unused pesticides in aerial application. The system consists of waterproof floor washing, settling pit tank, oxidation system using ozone and volatilization bed. This study was divided into two phases. In Phase 1, followed up campaigns of aerial applications, collecting data such as: amount of effluent generated, water consumed and the pesticides used to generate informations for the proposed study and know the environmental impact of aerial application of pesticides.The average water consumption was 112.8 L and the production of effluent was 132.8 L by washing.In Phase 2, were done physical and chemical analysis, concentration and charge of the active principles of pesticides in the effluent, in the steps of treatment system.The effluent was subjected to two distinct rates of ozone, 1.0 and 2.0 g O3/hour to assess the degree of degradation by the difference of concentration.The system reduced concentrations of Pyraclostrobin of the effluent in 97%, Epoconazole 98.1%, Imazethapyr 92.4%, Imazapic 91,8% and Flufenoxuron 82.8% for the rate of 1.0 g O3/hour, and to 2.0 g reduced Pyraclostrobin concentration in 85.1% , Epoconazole 97.1%, Imazethapyr 97.1%, Imazapic 94.7% and Flufenoxuron 86.0%.With the reduction of the load from the Sample 1 (without the effect of Sample C.O.), it was found that there was a reduction of Pyraclostrobin in 90.8%, Epoconazole 73.0%, Imazethapyr 69.1%, Imazapic 71,8% and Flufenoxuron 44.8% to rate O3/ hour 1.0 g, and for 2.0 g Pyraclostrobin decreased 50.3%, Epoconazole 59.3%, Imazethapyr 80.7%, Imazapic 82.4% and Flufenoxuron 63.2%. The Chemical Oxygen Demand of effluent pesticides after completing treatment showed values above allowed to release into the environment legislation, especially CONSEMA Resolution 128/2006 limiting at 400 mg O2/L for flows less than 20 m3/day. Cascade equals 2165.00 with COD mg O2/L, Opera 4191 mg O2/L, and Only with 668.50 mg O2/L. The treatment system worked decreasing the concentration and the load of pesticides and retained the final product of the treatment, given the agricultural and environmental legislation, and the economic and technical characteristics of agricultural aviation companies.
4

Tratamento de efluentes gredaos pela lavagem de aeronaves agrícolas e pelo descarte das aplicações aéreas de agrotóxicos / Treatment system of wastewater generated by washing and disposal of aerial applications of pesticides

Furtado, Ricardo Dourado January 2012 (has links)
Esta tese tem como objetivo analisar a eficiência de um sistema de tratamento de efluentes gerados na lavagem de aeronaves agrícolas e pelo descarte dos agrotóxicos não utilizados na aplicação aérea. O sistema é composto por piso de lavagem impermeabilizado, tanque de decantação, sistema de oxidação por ozônio e leito de volatilização. Esta pesquisa foi dividida em duas fases. Na Fase 1, acompanhou-se as campanhas de aplicações aéreas, coletando-se dados como: quantidade de efluente gerado, de água consumida e os agrotóxicos utilizados a fim de gerar informações para o experimento proposto e conhecer o impacto ambiental da aplicação aérea de agrotóxicos. O consumo médio de água foi de 112,8L e a produção de efluente foi de 132,8L, por lavagem. Na Fase 2, realizaram-se análises físicas e químicas, da concentração e da carga dos princípios-ativos dos agrotóxicos do efluente, nas etapas do sistema de tratamento. O efluente foi submetido a duas taxas distintas de ozônio, 1,0 e 2,0 g de O3/hora, para avaliar o grau de degradação pela diferença de concentração.O sistema reduziu as concentrações de Piraclostrobina do efluente em 97%, Epoconazole 98,1%, Imazetapir 92,4%, Imazapic 91,8% e Flufenoxuron 82,8%, para taxa de 1,0 g de O3/hora; e para 2,0 g reduziu a concentração de Piraclostrobina em 85,1%, de Epoconazole 97,1%, Imazetapir 97,1%, Imazapic 94,7% e Flufenoxuron 86,0 %. Com a redução da carga a partir da Amostra 1 (sem o efeito do C.O.), constatou-se redução de Piraclostrobina em 90,8%, de Epoconazole 73,0%, Imazetapir 69,1%, Imazapic 71,5% e Flufenoxuron 44,8%, para taxa de 1,0 g de O3/hora ; e para 2,0 g houve redução de Piraclostrobina em 50,3%, de Epoconazole 59,3%, Imazetapir 80,7%, Imazapic 82,4% e Flufenoxuron 63,2. A Demanda Química de Oxigênio do efluente dos agrotóxicos após completar o tratamento apresentou valores acima do permitido para lançamento no meio ambiente, pela legislação ambiental, principalmente a Resolução CONSEMA 128/2006 que limita em 400 mg de O2/L para vazões inferiores a 20 m3/dia. O Cascade com DQO igual a 2.165,00 mg de O2/L, o Opera 4.191 mg de O2/L, e o Only com 668,50 mg de O2/L. O sistema de tratamento funcionou diminuindo a concentração e a carga dos agrotóxicos e reteve o produto final do tratamento, atendendo as legislações agrícolas e ambientais, e as características econômicas e técnicas das empresas de aviação agrícola. / This thesis aims to analyze the efficiency of a system for treating wastewater generated by the washing of agricultural aircraft and the disposal of unused pesticides in aerial application. The system consists of waterproof floor washing, settling pit tank, oxidation system using ozone and volatilization bed. This study was divided into two phases. In Phase 1, followed up campaigns of aerial applications, collecting data such as: amount of effluent generated, water consumed and the pesticides used to generate informations for the proposed study and know the environmental impact of aerial application of pesticides.The average water consumption was 112.8 L and the production of effluent was 132.8 L by washing.In Phase 2, were done physical and chemical analysis, concentration and charge of the active principles of pesticides in the effluent, in the steps of treatment system.The effluent was subjected to two distinct rates of ozone, 1.0 and 2.0 g O3/hour to assess the degree of degradation by the difference of concentration.The system reduced concentrations of Pyraclostrobin of the effluent in 97%, Epoconazole 98.1%, Imazethapyr 92.4%, Imazapic 91,8% and Flufenoxuron 82.8% for the rate of 1.0 g O3/hour, and to 2.0 g reduced Pyraclostrobin concentration in 85.1% , Epoconazole 97.1%, Imazethapyr 97.1%, Imazapic 94.7% and Flufenoxuron 86.0%.With the reduction of the load from the Sample 1 (without the effect of Sample C.O.), it was found that there was a reduction of Pyraclostrobin in 90.8%, Epoconazole 73.0%, Imazethapyr 69.1%, Imazapic 71,8% and Flufenoxuron 44.8% to rate O3/ hour 1.0 g, and for 2.0 g Pyraclostrobin decreased 50.3%, Epoconazole 59.3%, Imazethapyr 80.7%, Imazapic 82.4% and Flufenoxuron 63.2%. The Chemical Oxygen Demand of effluent pesticides after completing treatment showed values above allowed to release into the environment legislation, especially CONSEMA Resolution 128/2006 limiting at 400 mg O2/L for flows less than 20 m3/day. Cascade equals 2165.00 with COD mg O2/L, Opera 4191 mg O2/L, and Only with 668.50 mg O2/L. The treatment system worked decreasing the concentration and the load of pesticides and retained the final product of the treatment, given the agricultural and environmental legislation, and the economic and technical characteristics of agricultural aviation companies.
5

Tratamento de efluentes gredaos pela lavagem de aeronaves agrícolas e pelo descarte das aplicações aéreas de agrotóxicos / Treatment system of wastewater generated by washing and disposal of aerial applications of pesticides

Furtado, Ricardo Dourado January 2012 (has links)
Esta tese tem como objetivo analisar a eficiência de um sistema de tratamento de efluentes gerados na lavagem de aeronaves agrícolas e pelo descarte dos agrotóxicos não utilizados na aplicação aérea. O sistema é composto por piso de lavagem impermeabilizado, tanque de decantação, sistema de oxidação por ozônio e leito de volatilização. Esta pesquisa foi dividida em duas fases. Na Fase 1, acompanhou-se as campanhas de aplicações aéreas, coletando-se dados como: quantidade de efluente gerado, de água consumida e os agrotóxicos utilizados a fim de gerar informações para o experimento proposto e conhecer o impacto ambiental da aplicação aérea de agrotóxicos. O consumo médio de água foi de 112,8L e a produção de efluente foi de 132,8L, por lavagem. Na Fase 2, realizaram-se análises físicas e químicas, da concentração e da carga dos princípios-ativos dos agrotóxicos do efluente, nas etapas do sistema de tratamento. O efluente foi submetido a duas taxas distintas de ozônio, 1,0 e 2,0 g de O3/hora, para avaliar o grau de degradação pela diferença de concentração.O sistema reduziu as concentrações de Piraclostrobina do efluente em 97%, Epoconazole 98,1%, Imazetapir 92,4%, Imazapic 91,8% e Flufenoxuron 82,8%, para taxa de 1,0 g de O3/hora; e para 2,0 g reduziu a concentração de Piraclostrobina em 85,1%, de Epoconazole 97,1%, Imazetapir 97,1%, Imazapic 94,7% e Flufenoxuron 86,0 %. Com a redução da carga a partir da Amostra 1 (sem o efeito do C.O.), constatou-se redução de Piraclostrobina em 90,8%, de Epoconazole 73,0%, Imazetapir 69,1%, Imazapic 71,5% e Flufenoxuron 44,8%, para taxa de 1,0 g de O3/hora ; e para 2,0 g houve redução de Piraclostrobina em 50,3%, de Epoconazole 59,3%, Imazetapir 80,7%, Imazapic 82,4% e Flufenoxuron 63,2. A Demanda Química de Oxigênio do efluente dos agrotóxicos após completar o tratamento apresentou valores acima do permitido para lançamento no meio ambiente, pela legislação ambiental, principalmente a Resolução CONSEMA 128/2006 que limita em 400 mg de O2/L para vazões inferiores a 20 m3/dia. O Cascade com DQO igual a 2.165,00 mg de O2/L, o Opera 4.191 mg de O2/L, e o Only com 668,50 mg de O2/L. O sistema de tratamento funcionou diminuindo a concentração e a carga dos agrotóxicos e reteve o produto final do tratamento, atendendo as legislações agrícolas e ambientais, e as características econômicas e técnicas das empresas de aviação agrícola. / This thesis aims to analyze the efficiency of a system for treating wastewater generated by the washing of agricultural aircraft and the disposal of unused pesticides in aerial application. The system consists of waterproof floor washing, settling pit tank, oxidation system using ozone and volatilization bed. This study was divided into two phases. In Phase 1, followed up campaigns of aerial applications, collecting data such as: amount of effluent generated, water consumed and the pesticides used to generate informations for the proposed study and know the environmental impact of aerial application of pesticides.The average water consumption was 112.8 L and the production of effluent was 132.8 L by washing.In Phase 2, were done physical and chemical analysis, concentration and charge of the active principles of pesticides in the effluent, in the steps of treatment system.The effluent was subjected to two distinct rates of ozone, 1.0 and 2.0 g O3/hour to assess the degree of degradation by the difference of concentration.The system reduced concentrations of Pyraclostrobin of the effluent in 97%, Epoconazole 98.1%, Imazethapyr 92.4%, Imazapic 91,8% and Flufenoxuron 82.8% for the rate of 1.0 g O3/hour, and to 2.0 g reduced Pyraclostrobin concentration in 85.1% , Epoconazole 97.1%, Imazethapyr 97.1%, Imazapic 94.7% and Flufenoxuron 86.0%.With the reduction of the load from the Sample 1 (without the effect of Sample C.O.), it was found that there was a reduction of Pyraclostrobin in 90.8%, Epoconazole 73.0%, Imazethapyr 69.1%, Imazapic 71,8% and Flufenoxuron 44.8% to rate O3/ hour 1.0 g, and for 2.0 g Pyraclostrobin decreased 50.3%, Epoconazole 59.3%, Imazethapyr 80.7%, Imazapic 82.4% and Flufenoxuron 63.2%. The Chemical Oxygen Demand of effluent pesticides after completing treatment showed values above allowed to release into the environment legislation, especially CONSEMA Resolution 128/2006 limiting at 400 mg O2/L for flows less than 20 m3/day. Cascade equals 2165.00 with COD mg O2/L, Opera 4191 mg O2/L, and Only with 668.50 mg O2/L. The treatment system worked decreasing the concentration and the load of pesticides and retained the final product of the treatment, given the agricultural and environmental legislation, and the economic and technical characteristics of agricultural aviation companies.
6

Ozone Treatment Targeting Pharmaceutical Residues : Validation and Process Control in a Wastewater Treatment Plant

Fornander, Erik January 2018 (has links)
Major studies conducted in Europe and North America has concluded that the current processes in wastewater treatment plants insufficiently degrade micropollutants e.g. pharmaceutical residues. Several sorption and oxidation methods has therefore been investigated with the purpose of removing or degrading micropollutants in wastewater. The main purpose of this project was, firstly, to validate the results from a pilot study conducted by Tekniska verken i Linköping AB (2014) which investigated the use of ozone to degrade pharmaceutical residues. Secondly, to investigate and design a suitable process control strategy for the ozonation process. Four different tests were conducted during the project, a dose-response test, step-response tests, a trace test, and a performance test. A poorer average reduction of pharmaceutical residues was observed in this project compared to the pilot study. An average reduction of approximately 80% was observed at the highest tested dose, 0.67 mg O3/mg DOC, N corr. Whilst an average reduction of 90% was observed at approximately 0.46 mg O3/mg DOC, N corr, in the pilot study. However, the quality of the wastewater was worse during this project compared to the pilot study. ΔUVA254 and offgas concentration of ozone were found to be suitable control parameters for process control. A control strategy based on a combination of these parameters was designed, where ΔUVA254 was used as the main control parameter and the off-gas concentration of ozone was used as a limiting controller to ensure a sufficient mass transfer in the system. In conclusion, a suitable flow proportional base ozone dose valid for current water conditions has been identified, 10 mg/L. Differences in wastewater quality which heavily influence the ozonation process have been identified. Lastly, a control strategy for process control of the ozonation have been identified, designed and is ready for implementation.
7

Organic Photovoltaic Optimization: A Functionalized Device Based Approach

Theibert, Dustin January 2013 (has links)
No description available.

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