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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.
51

Tratamento de água de produção de petróleo através de membranas e processos oxidativos avançados / Treatment of produced-water by membranes and advanced oxidative processes

Vanessa Augusta Pires de Macedo 16 October 2009 (has links)
A exploração de petróleo é uma das mais importantes atividades industriais da sociedade moderna e seus derivados tem inúmeras aplicações em relação processos industriais.A água que é separada do petróleo é chamada água de produção de petróleo. A composição da água de produção de petróleo é muito complexa, sendo a alta salinidade sua característica marcante podendo chegar a 120 g .L-1. em cloretos. Devido ao volume e a complexidade da água de produção de petróleo o seu tratamento é um grande problema para as indústrias petrolíferas. Neste trabalho foi possível concluir que a combinação das técnicas de coagulação/floculação, microfiltração e processos oxidativos avançados (TiO2/UV/H2O2) foi eficiente para a remoção de fenol da água de produção de petróleo. Na etapa de coagulação/floculação o tempo de repouso, a interação entre o agente coagulante e o pH assim como a interação dos três parâmetros analisados foi estatisticamente significativa para remoção de turbidez considerando um grau de 95% de confiança. Nesta etapa a maior redução de turbidez foi obtida utilizando PAC como agente coagulante em pH 3 e tempo de repouso da amostra de 10 min. A seqüência de tratamentos proposta (coagulação/floculação; membranas; POAs) não se mostrou economicamente viável devido à necessidade de remoção do TiO2 no final do processo. / Oil exploration is one of the most important industrial activities of modern society and their products have numerous applications in industrials process. The water that is separated from oil production is called produced water. The composition of this water is very complex, high salinity and phenol are it principal characteristic, chlorides may reach 120 g.L-1. Due to the volume and complexity of the produced water it treatment is the major problem of the oil industries. In this study it was concluded that the combination of the techniques of coagulation / flocculation, microfiltration and advanced oxidation processes (TiO2/UV/H2O2) was efficient for phenol removal. During the coagulation / flocculation step, the rest time, the interaction between coagulant agent and pH as well as the interaction of the three analyzed parameters was significant for turbidity removal considering a 95% of confidence. At this stage the greatest reduction of turbidity was obtained using PAC as coagulant agent at pH 3 and 10 minutes sample of rest time. The proposed treatment sequence (coagulation / flocculation; membranes; AOPs) was not economically viable due to necessity of TiO2 removal at the end of the process.
52

Tratamento de efluente têxtil através de processos redox e separação com membranas combinados / Treatment of textile wastewater by combination of redox and membrane separation processes

Rodrigo Neder Alvarenga 14 August 2009 (has links)
O processamento têxtil gera grande quantidade de despejos altamente poluidores, contendo valores elevados de carga orgânica, cor acentuada e compostos químicos tóxicos ao homem e ao meio ambiente. Os efluentes têxteis apresentam uma variação muito grande na sua composição devido aos vários tipos de corantes e produtos químicos utilizados e isto faz o seu tratamento ser um problema complexo. Devido a estas implicações, novas tecnologias têm sido buscadas para a degradação ou imobilização destes compostos em efluentes têxteis dentre os quais a combinação de processos oxidativos avançados, redutivo e separação por membranas. Os processos de separação por membranas têm sido cada vez mais aplicados para separação, purificação e concentração de constituintes industriais, principalmente pelo desenvolvimento e eficiência da técnica e redução de custos com o passar dos anos. O processo redutivo utilizando Fe0 é bastante promissor, em função do custo relativamente baixo do ferro metálico e da sua elevada efetividade na degradação de contaminantes ambientais, sendo que após a oxidação do Fe0 a íons Fe2+ e Fe3+ estes íons podem ser aproveitados em sequência nos Processos Oxidativos Avançados (POAs). Os processos oxidativos avançados são tecnologias extremamente eficientes para destruição de compostos orgânicos de difícil degradação. Podem ser consideradas tecnologias limpas, pois não há a formação de subprodutos sólidos e nem a transferência de fase dos poluentes. Os POAs são baseados na geração de radicais fortemente oxidativos, principalmente o radical hidroxila (HOo), que destroem inúmeros compostos de maneira rápida e pouco seletiva, quando comparado aos processos convencionais, conduzindo a mineralização parcial ou completa dos contaminantes. Com o objetivo de estudar o efeito destes processos na melhoria do efluente têxtil foi utilizado um efluente de uma indústria têxtil de grande porte do interior de São Paulo. Ao ser coletado, este efluente foi caracterizado e submetido à permeação por membranas de microfiltração (0,45 μm). Este tratamento possibilitou a redução de 37,7 % do COT e 40,9 % da Área Espectral (200-800 nm) em comparação com o efluente original. O efluente oriundo do tratamento com membranas foi submetido, através de planejamento de experimentos, aos processos oxidativos avançados do tipo foto-Fenton e foto-Fenton avançado (utilizando Fe0) visando à melhoria para despejo ou reúso deste efluente. Na melhor condição de reação foi possível alcançar uma redução de aproximadamente 73,0 % em COT e 93,0 % em área espectral após uma hora de reação para os dois tipos de POAs. A combinação das tecnologias de membranas e processos oxidativos avançados mostrou-se extremamente positiva quanto à melhoria da deste efluente têxtil, possibilitando a redução em torno de 83,0 % do COT e 95,0 % da área espectral. / The textile manufacturing generates large amounts of highly polluting sewage containing high levels of organic load, color and chemical compounds toxic to human beings and to the environment. This textile wastewater has a great variation in its composition due to various types of dyes and chemicals used. All these considerations make the textile wastewater treatment a complex problem. Due to these implications, new technologies have been studied for degradation or immobilization of these compounds in textile wastewater among which the combination of advanced oxidative, reductive and separation with membranes processes. The separation processes with membranes have been increasingly applied for separation, purification and concentration of industrial components, mainly development in technology and efficient cost savings over the years. The reductive process using Fe0 is very promising because of the relatively low cost of metallic iron and its high effectiveness in the degradation of environmental contaminants. After the oxidation of Fe0 to Fe2+ and Fe3+ these ions can be used in sequence in the Advanced Oxidative Process (AOPs). The advanced oxidative process technologies are extremely effective for degradation of organic compounds with difficult degradation. It can be considered as a clean technology, because there is no formation of solid subproducts, neither the phase transfer of pollutants. The AOPs are based on the generation of highly oxidative radicals, particularly hydroxyl radical (HOo), which destroys many compounds to a rapid and low selective way compared with conventional process of treatment, leading to partial or complete mineralization of contaminants. A wastewater from a large textile industry in São Paulo was used in order to study the effect of these processes in the improvement of textile wastewater quality. Firstly, the wastewater was characterized and subjected to permeation by microfiltration membrane (0.45 μm). This treatment allowed a reduction of 37.7 % of TOC and 40.9 % of spectral area (200-800 nm) compared to the original wastewater. The wastewater from the treatment with membranes was subjected, through design of experiments, the advanced oxidative processes of the type photo-Fenton and advanced photo-Fenton (using Fe0) aiming to improve the disposal or to reuse of wastewater. In the best experimental condition it was achieved a 73 % in TOC and 93 % in spectral area reduction after one hour of reaction for both types of AOPs. The membrane technologies and advanced oxidative combination process proved to be extremely positive on the textile wastewater quality improvement, resulting in a reduction of around 83 % of TOC and 95 % of spectral area.
53

Tratamento de água de produção de petróleo através de membranas e processos oxidativos avançados / Treatment of produced-water by membranes and advanced oxidative processes

Macedo, Vanessa Augusta Pires de 16 October 2009 (has links)
A exploração de petróleo é uma das mais importantes atividades industriais da sociedade moderna e seus derivados tem inúmeras aplicações em relação processos industriais.A água que é separada do petróleo é chamada água de produção de petróleo. A composição da água de produção de petróleo é muito complexa, sendo a alta salinidade sua característica marcante podendo chegar a 120 g .L-1. em cloretos. Devido ao volume e a complexidade da água de produção de petróleo o seu tratamento é um grande problema para as indústrias petrolíferas. Neste trabalho foi possível concluir que a combinação das técnicas de coagulação/floculação, microfiltração e processos oxidativos avançados (TiO2/UV/H2O2) foi eficiente para a remoção de fenol da água de produção de petróleo. Na etapa de coagulação/floculação o tempo de repouso, a interação entre o agente coagulante e o pH assim como a interação dos três parâmetros analisados foi estatisticamente significativa para remoção de turbidez considerando um grau de 95% de confiança. Nesta etapa a maior redução de turbidez foi obtida utilizando PAC como agente coagulante em pH 3 e tempo de repouso da amostra de 10 min. A seqüência de tratamentos proposta (coagulação/floculação; membranas; POAs) não se mostrou economicamente viável devido à necessidade de remoção do TiO2 no final do processo. / Oil exploration is one of the most important industrial activities of modern society and their products have numerous applications in industrials process. The water that is separated from oil production is called produced water. The composition of this water is very complex, high salinity and phenol are it principal characteristic, chlorides may reach 120 g.L-1. Due to the volume and complexity of the produced water it treatment is the major problem of the oil industries. In this study it was concluded that the combination of the techniques of coagulation / flocculation, microfiltration and advanced oxidation processes (TiO2/UV/H2O2) was efficient for phenol removal. During the coagulation / flocculation step, the rest time, the interaction between coagulant agent and pH as well as the interaction of the three analyzed parameters was significant for turbidity removal considering a 95% of confidence. At this stage the greatest reduction of turbidity was obtained using PAC as coagulant agent at pH 3 and 10 minutes sample of rest time. The proposed treatment sequence (coagulation / flocculation; membranes; AOPs) was not economically viable due to necessity of TiO2 removal at the end of the process.
54

以SQL語句剖析結合剖面技術設計實作資料隱碼攻擊之防禦工具 / An Anti-SQLIA tool based on SQL parsing and aspect technology

王瑛瑛, Wang, Ying Ying Unknown Date (has links)
資料隱碼攻擊(SQLIA)是一種Web應用程式弱點,這個弱點為Web客戶端輸入值隱藏攻擊字串而改變了動態產生的SQL語句結構。根據OWASP(Open Web Application Security Project)2010年的網站風險評鑑報告,資料隱碼攻擊被列為最嚴重的Web應用程式風險。資料隱碼攻擊的弱點可能讓攻擊者能夠直接存取資料庫,導致敏感性資料遭到修改或竊取,有經驗的攻擊者,甚至可以利用一個資料隱碼攻擊的漏洞,而接管整個應用系統。 在本篇論文中,我們基於資料隱碼攻擊的原理實作一個自動化的防禦工具。我們的工具以SQL語句剖析結合剖面技術實作,利用窮舉法,動態分析及動態監控應用程式所執行的SQL語句,毋須開發者學習新的程式寫法或修改應用程式,即能將防禦機制套用於應用程式(原始碼及中間碼),並透過使用者介面設定可動態調整防禦監控的範圍,提供一個有效保護WEB應用程式的資料隱碼攻擊防禦機制。 / SQL injection attack (SQLIA) is a type of attack on web applications that exploits the fact that input provided by web clients may be directly included in the dynamically generated SQL statements. According to the WASP Foundation, injection attacks, particularly SQL injection, were the most serious web application vulnerability type in 2010. By using SQLIA, an attacker may directly access the database underlying a web application and modify or expose sensitive information. A proficient attacker can even use an SQLIA to completely compromise the host system. In this thesis, we study SQL injection attacks and develop a fully automated, configurable tool for protecting web applications against SQLIA. Our tool uses a heuristic method that combines runtime learning and runtime monitoring of valid/legal SQL statements, by parsing them to calculate and verify MD5 represented patterns (called SQL fingerprints) respectively, and is implemented in Java and AspectJ in order to achieve the goal that requires no training of developers and no modification of the legacy applications. Our evaluation results have shown this tool to be highly effective at protecting web applications from all types of SQL injection attacks.
55

Application des techniques d’oxydation avancée pour la dépollution des effluents organiques dans les eaux de rejets industriels : cas des savonneries / Advanced oxidation processes applied to organics micropollutants contained in industrial wastewater : case of soap factories

Dalhatou, Sadou 17 April 2014 (has links)
Dans le cadre de l'élimination de composés réfractaires contenu dans une matrice complexe, les procédés d'oxydation avancée s'avèrent être une technologie de choix. Cette étude est donc consacrée à la sonolyse et à la photolyse de deux xénobiotiques organiques, le naphthol blue black (un colorant hydrophile, noté NBB) et le nonylphénol (un détergent, hydrophobe et volatil, noté NP), seuls ou en compétition. L'efficacité de la technique ultrasonore de haute fréquence (278 kHz) a été testée sur les molécules cibles et leur mélange. La décoloration du NBB est effective après 180 min de traitement et s'accompagne d'une minéralisation de 23% alors que le NP se dégrade après 120 min. L'effet des paramètres a été étudié, tels que la puissance ultrasonore, la concentration du substrat, le pH, les ions inorganiques (bicarbonates et phosphates) et la compétition. Ainsi dans le mélange, la présence du NBB n'a pas d'influence sur la disparition sur NP tandis que la décoloration du NBB est affectée par la présence du NP. Cependant, la présence des ions bicarbonates dans le mélange permet par l'intermédiaire des radicaux carbonates de contrebalancer l'effet inhibiteur du NP. L'utilisation de la photolyse directe a fait l'objet de la deuxième partie de ce travail, ce qui a permis de faire une étude comparative des deux techniques. Il a été montré que la sonochimie, fort de sa capacité à produire abondamment les radicaux HO•, est plus adaptée au traitement des effluents relativement plus concentrés. De plus, la sonochimie permet de mettre en valeur les ions inorganiques, constituants naturels de l'eau pour minimiser l'effet inhibiteur de la matrice. Ensuite, l'efficacité de certains Procédés d'Oxydation Avancée (POA) sur l'élimination des xénobiotiques sus-mentionnés a été testée et les résultats obtenus ont donné lieu à l'ordre suivant : UV < UV/H2O2 < Fe2+/H2O2 < UV/Fe2+/H2O2. / Within the framework of the destruction of refractory organics contained in a complex aqueous matrix, the advanced oxidation processes appear to be a first class technology. So this survey is dedicated to the sonolysis and the photolysis of two organics, namely the naphthol blue black (an acid azo-dye, hydrophilic, noted NBB) and the nonylphenol (a detergent, hydrophobic et volatile, noted NP), single or in competition. High frequency (278 kHz) ultrasound is found to be efficient. NBB decolorization is effective within 180 min and its mineralization reaches 23% while NP is degraded for 120 min. Different parameters were studied, such as ultrasound power, substrate concentration, pH, inorganic ions (bicarbonate and phosphate), and competition. In the NBB/NP mixture, NBB has no influence on the NP degradation whereas NP has a strong effect on the NBB decolorization. Nevertheless, the presence of bicarbonate ions in the mixture reduces the negative effect of NP, thanks to the formation of carbonates radicals. Direct photolysis is the topic of the second part of this study, so as to make a comparison of these two oxidative techniques. It was emphasizes that sonolysis is most adapted for the treatment of more concentrated pollutant, because of the intense production of HO• radicals. Moreover sonolysis is relevant when inorganic ions are present in the mixture, in order to minimize the competition between organics. Then the efficiency of different AOP was tested for the two target pollutants; results can be organized according the following: UV < UV/H2O2 < Fe2+/H2O2 < UV/Fe2+/H2O2.
56

Otimização da reação de fenton visando aplicações na remediação in-situ e ex-situ de aguas subterraneas / Optimization of fenton's reaction aiming at in-situ and ex-situ groundwater remediation

Andrade, Juliano de Almeida 26 August 2005 (has links)
Orientador: Wilson de Figueiredo Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T10:39:52Z (GMT). No. of bitstreams: 1 Andrade_JulianodeAlmeida_M.pdf: 3254677 bytes, checksum: 72d1e108844df115bda11c77f7fd1337 (MD5) Previous issue date: 2005 / Mestrado / Quimica Analitica / Mestre em Química
57

Aspectualizing Component Models : implementation and Interferences Analysis / Aspectualiser les modèles de composants : implémentation et analyse d'interférence

Hannousse, Abdelhakim 14 November 2011 (has links)
L'utilisation d'AOP pour modéliser les préoccupations transverses ou non modulaire de CBSE assure une meilleure modularité et réutilisabilité des composants. Dans ce cadre, nous proposons une approche générique pour modéliser les aspects dans les modèles à composants. Nous modélisons un aspect par un wrapper sur une vue de système. Une vue décrit une configuration adéquate du système où tous les composants dans l'intérêt d'un aspect sont encapsulés dans le même composite. Pour la définition des vues, nous définissons un langage déclaratif VIL. Nous illustrons comment les vues sont mises en œuvre dans des modèles à composants (ex., Fractal), et nous fournissons un modèle formel pour l'analyse des interférences d'aspects. Les composants et les aspects sont modélisés par des automates et Uppaal est utilisé pour détecter les interférences. Pour la résolution d'interférences, nous fournissons un ensemble d'opérateurs de composition. Notre approche est illustrée par un exemple : l'accès wifi dans un aéroport. / Using AOP to model non-modular concerns in CBSE ensures better modularity and reusability of components. In this thesis, we provide a model independent approach for modeling aspects in component models. In the approach we model aspects as wrappers on views of component systems. A view describes an adequate component system configuration where all the components of interest of an aspect are encapsulated in the same composite.For declarative definition of views, we provide a declarative language VIL. We illustrate how views are implemented in component models(e.g., Fractal). We provide a formal framework for aspect interferences analysis. In the framework component systems and aspects are modeled as automata and Uppaal model checker is used for the detection of aspect interferences. For interferences resolution, we provide a set of composition operators as templates to be instantiated for any two arbitrary aspects. Our approach is illustrated with an airport wireless access example.
58

Využití oxidačních procesů (AOP) pro odstraňování mikropolutantů / Use of oxidation processes (AOP) for removal of micropolutants

Stříteský, Luboš January 2013 (has links)
This thesis deals with advanced oxidation processes (AOPs) and it’s use for removal of micropollutants from wastewater. The first chapter explains the need AOPs, water quality, pollution and substances that are present in the water. Further, the first chapter outlines approach of the current legislation to micropollutants. The second chapter explains the theory and principle of operation of AOPs. This chapter is divided into two sections. The first section describes AOPs, which were tested at selected WWTP. In the second section, there are described some other AOPs. The third chapter is a literature retrieval of AOPs dealing with the removal of micropollutants. This chapter is focused on the removal of hormones by AOPs using ozone-based AOPs. The fourth chapter describes the actual testing of selected AOPs. The chapter describes selected WWTP, pilot-scale AOP unit and test results. In the last chapter there is designed and described full-scale AOP tertiary unit for removing of micropollutants. The last chapter also contains economic analysis of the proposed tertiary unit.
59

Thermal lens spectrometric detection of MRI contrast agents in the process of their photocatalytic degradation / Thermal lens spectrometric detection of MRI contrast agents in the process of their photocatalytic degradation

Petruľák, Michal January 2016 (has links)
Diplomová práce je zaměřena na studium degradace kontrastních látek pro magnetickou rezonanci. Tyto látky se dnes ve velké míře používají v oblastech s rozvinutým zdravotnictvím. Můžeme je najít v odtocích z čistíren odpadních vod, což svědčí o tom, že běžné stupně čištění odpadních vod nejsou dostatečně efektivní pro jejich odstranění. O degradaci kontrastních látek na bázi gadolinia je jen málo informací. Fotokatalytický rozklad za pomoci oxidu titaničitého a také ozonace vybrané kontrastní látky gadobutrolu, byl sledován pomocí měření celkového organického uhlíku, mikroskopie termálních čoček a spektrofotometrie.
60

Oxidation of Selected Trace Organic Compounds through the Combination of Inline Electro-Chlorination with UV Radiation (UV/ECl2) as Alternative AOP for Decentralized Drinking Water Treatment

Otter, Philipp, Mette, Katharina, Wesch, Robert, Gerhardt, Tobias, Krüger, Frank-Marc, Goldmaier, Alexander, Benz, Florian, Malakar, Pradyut, Grischek, Thomas 23 March 2022 (has links)
A large variety of Advanced Oxidation Processes (AOPs) to degrade trace organic compounds during water treatment have been studied on a lab scale in the past. This paper presents the combination of inline electrolytic chlorine generation (ECl2) with low pressure UV reactors (UV/ECl2) in order to allow the operation of a chlorine-based AOP without the need for any chlorine dosing. Lab studies showed that from a Free Available Chlorine (FAC) concentration range between 1 and 18 mg/L produced by ECl2 up to 84% can be photolyzed to form, among others, hydroxyl radicals (OH) with an UV energy input of 0.48 kWh/m3. This ratio could be increased to 97% by doubling the UV energy input to 0.96 kWh/m3 and was constant throughout the tested FAC range. Also the achieved radical yield of 64% did not change along the given FAC concentration range and no dependence between pH 6 and pH 8 could be found, largely simplifying the operation of a pilot scale system in drinking water treatment. Whereas with ECl2 alone only 5% of benzotriazoles could be degraded, the combination with UV improved the degradation to 89%. Similar results were achieved for 4-methylbenzotriazole, 5-methylbenzotriazole and iomeprol. Oxipurinol and gabapentin were readily degraded by ECl2 alone. The trihalomethanes values were maintained below the Germany drinking water standard of 50 µg/L, provided residual chlorine concentrations are kept within the permissible limits. The here presented treatment approach is promising for decentralized treatment application but requires further optimization in order to reduce its energy requirements.:Introduction Methodology Results and Discussion Conclusions Author Contributions Funding Conflicts of Interest Appendix A References

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