Dissertations / Theses on the topic 'TIG-2'
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Kelča, Daniel. "Svařování tenkostěnných trubek." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229355.
Full textCarvalho, Sheila Medeiros de. "Estudo da soldabilidade a laser e a TIG do titânio comercialmente puro grau 2 empregado em sistemas pneumáticos de aeronaves." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/97/97134/tde-02102013-112909/.
Full textThe engine bleed air system, also known as pneumatic system, conducts the pressurized hot air from the engine to the environmental systems of aircrafts. In-service failures of the arc welded pneumatic parts have driven further developments of laser beam welding as an alternative method. Here, a fiber laser with 2 kW power had been employed to weld commercial purity titanium alloy tubes with 0.5 wall thickness and 50 mm diameter. For comparison purposes, semiautomatic TIG welding was realized, based on the previous experience of an aircraft company. All the welds were autogenous, bead-on-plate, and under protective argon atmosphere. The chosen parameters speed and laser powers for laser welding were 200 W - 2000 mm/min and 250 W - 300 mm/min. The laser welded tubes presented 1-mm wide weld beads composed by grained ?-Ti. The TIG welded tubes showed 5-mm wide beads composed by acicular ?-Ti grains. These observed differences had been associated to the cooling rate, which is seventy times higher in the laser case. Both laser and TIG welded tubes were cycled 44.000 times in a pneumatic bench at 350 oC without failures or cracks that could break the internal pressure. The condition 200W-2000mm/min presented superior fatigue resistance values compared to other welding conditions, and being similar to the tubes in the unwelded condition. On the other hand, the condition 250W-3000mm/min presented the highest dispersion for the fatigue lives. The microstructural and mechanical results shown that the current laser technology could replace with advantages the arc welding for the joining of the titanium tubes in the aircrafts pneumatic system.
Billotte, Thomas. "Caractérisation et modélisation des structures de solidification en soudage TIG d’alliages austénitiques." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0084/document.
Full textToday, industrials want to upgrade their welding numerical simulation knowledge’s in order to be able to guarantee the welded structure integrity. Solidification is the main step of welding process. As soon as the grain selection in welded region is well reproduced by simulation software, mechanical properties and nondestructive test response can be deduced. This work tries to find thermometallurgical phenomena in order to describe the microstructures formation during welding. These mechanisms are used for validating a new solidification model which realizes a thermal calcul post-treatment with a cellular automaton (CAFE_WELD). In this aim, welding experiences were done and characterized with EBSD. These analyses allow following the grain selection into the weld. The refusion effect is clearly seen in the case of multi-pass weld. These results are completed by the fine solidification characterizations on filler metal employed in welding experiences. In this way, the model implementation can be done in order to do numerical simulation of the same experiences. The comparisons between real and numerical experiences show that the physical laws taken into account in CAFE_WELD model are not sufficient to reproduce the microstructural properties occurring in welding
Шовкопляс, Оксана Анатоліївна, Оксана Анатольевна Шовкопляс, Oksana Anatoliivna Shovkoplias, О. В. Соболь, and В. М. Береснєв. "Фізико-механічні властивості іонно-плазмових покриттів квазібінарних систем TiB[2]-WB[2] і TiC-WC." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40810.
Full textWang, Kang. "Pressureless sintering and mechanical properties of TiN-TiB¦2 particulate ceramic composites." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2002. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ65652.pdf.
Full textCaceda, Diaz Patricia, Xxxx Christopher Creighton Cox, and Cano Monica Terrones. "Inglés TI3 - TR06 2 01801." Universidad Peruana de Ciencias Aplicadas (UPC), 2018. http://hdl.handle.net/10757/623339.
Full textAlmeida, Marciano Fabiano de. "Atividade fotocatalítica de compósitos hidrotalcita-TiO 2 impregnados com nanopartículas metálicas e TiO 2 -óxidos mistos de MgZnAl." Universidade Federal de Viçosa, 2015. http://www.locus.ufv.br/handle/123456789/8530.
Full textMade available in DSpace on 2016-09-08T17:11:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1835695 bytes, checksum: bf8f63b434564b64b6fde68bc988c9e5 (MD5) Previous issue date: 2015-12-08
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A utilização do TiO 2 como fotocatalisador apresenta algumas desvantagens como os processos de recombinação elétrons-lacuna, os quais diminuem a sua atividade fotocatalítica; somente ser fotoativado pela radiação na região do UV; e tendência a agregação das suas nanopartículas. Desta forma, este trabalho consistiu-se no preparo de compósitos contendo TiO 2 de forma a obter uma melhoria em suas propriedades funcionais. A atividade fotocatalítica foi significativamente afetada pela quantidade de TiO 2 suportada no hidróxido duplo lamelar de MgAl (hidrotalcita). Várias amostras de fotocatalisadores foram preparadas com diferentes nanopartículas metálicas (Ag, Cu ou Ni). O compósito fotocatalisador mais eficiente foi obtido na forma calcinada, com a relação molar de 2:1:1 (Mg:Al:Ti) e o metal Ag (2%, m/m) sendo denominado por HTC/TiO 2 -Ag(2). Este compósito apresentou aproximadamente 100% de degradação e 85% de mineralização do fenol, em 300 min. Compósitos contendo TiO 2 associado ao óxido de zinco obtido pela calcinação do hidróxido duplo lamelar ternário de MgZnAl também foram preparados com sucesso. Os fotocatalisadores foram avaliados em diferentes razões molares de Zn 2+ /Mg 2+ sendo que o melhor fotocatalisador foi obtido para a razão molar Zn 2+ /Mg 2+ igual a 5% e foi denominado por TiO 2 /MgZnAl-5. Este fotocatalisador removeu aproximadamente 100% de fenol e 80% de COT, em 360 minutos. Os novos compósitos fotocatalisadores preparados neste trabalho apresentaram um sinergismo de efeito ocasionado pelo suporte de hidróxido duplo lamelar, presença das nanopartículas metálicas (Ag, Cu ou Ni) ou óxido de zinco os quais, associados à fotoatividade do TiO 2, resultaram na formação de um compósito com alta capacidade fotocatalítica. Os compósitos apresentaram boa estabilidade após 5 ciclos de reuso, capacidade de recuperação e menor agregação de suas nanopartículas, mostrando assim um potencial promissor para aplicações práticas.
Use of TiO 2 as photocatalyst has some disadvantages such as electron-hole recombination processes which reduces its photocatalytic activity; only be photoactivated by radiation in UV region; and the tendency of aggregation when used as nanopowder. This study consisted in preparing composites containing TiO 2 to obtain an improvement in their functional properties. Photocatalytic activity was affected significantly by the amount of TiO 2 supported on lamellar double hydroxide of MgAl (hydrotalcite). A series of photocatalysts were prepared with different metallic nanoparticles (Ag, Cu or Ni). The most efficient photocatalyst composite was obtained calcined form, molar ratio 2:1:1 (Mg:Al:Ti) and Ag metal (2 wt.%) denominated as HTC/TiO 2 -Ag(2). This composite showed highest efficiency degradation by removing about 100% phenol by analysis via HPLC-DAD and 85% TOC after 300 minutes. Composites containing TiO 2 combined with zinc oxide obtained by the calcination of ternary (MgZnAl) layered double hydroxides were also successfully prepared in this work. The photocatalysts were evaluated at different Zn 2+ /Mg 2+ molar rations and the most efficient photocatalyst was obtained at a Zn 2+ /Mg 2+ equal to 5% (TiO 2 /MgZnAl- 5). This photocatalyst removed approximately 100% phenol and 80% COT after 360 minutes. The new composite photocatalyst prepared in this study showed a synergy effect of the layered double hydroxide support, presence of metal nanoparticles (Ag, Cu or Ni) or zinc oxide associated with photoactivity of TiO 2 , resulting in formation of a composite with high photocatalytic capacity. The composites showed good stability after 5 cycles, reduced agglomeration and ease separation by sedimentation at the end of the processes, thus showing a promising potential for practical applications.
Mario, Romero Ramirez Hugo, Gomez De La Torre Salas Cesar Enrique, Cargol Noguer Josep Jordi, Chullen Galbiati Pier Paolo Eduardo, and Contreras Velez Jorge Julian. "Tix - Arquitectura Y Ciudad 2-AR146-201301." Universidad Peruana de Ciencias Aplicadas (UPC), 2013. http://hdl.handle.net/10757/630170.
Full textMario, Romero Ramirez Hugo, Gomez De La Torre Salas Cesar Enrique, Cargol Noguer Josep Jordi, Chullen Galbiati Pier Paolo Eduardo, and Contreras Velez Jorge Julian. "Tix - Arquitectura Y Ciudad 2-AR146-201302." Universidad Peruana de Ciencias Aplicadas (UPC), 2013. http://hdl.handle.net/10757/630171.
Full textRicardo, Uribe Tueros Pedro, Romero Ramirez Hugo Mario, Cargol Noguer Josep Jordi, and Chullen Galbiati Pier Paolo Eduardo. "Tix - Arquitectura Y Ciudad 2-AR146-201401." Universidad Peruana de Ciencias Aplicadas (UPC), 2014. http://hdl.handle.net/10757/630172.
Full textRicardo, Uribe Tueros Pedro, Romero Ramirez Hugo Mario, Cargol Noguer Josep Jordi, and Chullen Galbiati Pier Paolo Eduardo. "Tix - Arquitectura Y Ciudad 2-AR146-201402." Universidad Peruana de Ciencias Aplicadas (UPC), 2014. http://hdl.handle.net/10757/630173.
Full textRicardo, Uribe Tueros Pedro. "Tix - Arquitectura Y Ciudad 2-AR146-201500." Universidad Peruana de Ciencias Aplicadas (UPC), 2015. http://hdl.handle.net/10757/630174.
Full textRicardo, Uribe Tueros Pedro, Romero Ramirez Hugo Mario, Chullen Galbiati Pier Paolo Eduardo, and Alvariño Florian Rosa Mercedes. "Tix - Arquitectura Y Ciudad 2-AR146-201501." Universidad Peruana de Ciencias Aplicadas (UPC), 2015. http://hdl.handle.net/10757/630175.
Full textGUENEAU, LETHICIA. "Sites de surface, greffage et photodegradation d'organosilanes, sur sio#2 et tio#2." Paris 11, 1998. http://www.theses.fr/1998PA112424.
Full textБатальцев, Д. А., and М. В. Головкина. "Исследование параметров композитной среды с наночастицами TiO[2]." Thesis, Сумский государственный университет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/39559.
Full textLAHOUSSE, CHRISTOPHE. "Synthese, caracterisation et etude de l'acido-basicite d'oxydes mixtes zro#2-al#2o#3, tio#2-al#2o#3, zro#2-tio#2, mgo-al#2o#3, zno-al#2o#3." Caen, 1994. http://www.theses.fr/1994CAEN2042.
Full textAndersson, Ellen. "Krav på församlingsledare i den tidiga kristna kyrkan : En jämförelse mellan 1 Tim 3:2-7||Tit 1:6-9 och Paulus." Thesis, Uppsala universitet, Bibelvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-261181.
Full textПогребняк, Олександр Дмитрович, Александр Дмитриевич Погребняк, Oleksandr Dmytrovych Pohrebniak, and К. В. Смирнова. "Дослідження впливу на мікроструктуру нанокомпозитного AlN-TiB[2]-TiSi[2] високотемпературного відпалу та імплантації." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40799.
Full textOsugi, Marly Eiko [UNESP]. "Avaliação de processos de degradação de corantes dispersos por técnicas eletroquímica e fotoeletroquímica usando eletrodos de Pt, filmes finos e nanotubos de 'TI'/'TIO IND. 2' e bicomponentes 'W'/'WO IND. 3'/'TIO IND. 2'." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/105732.
Full textConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O comportamento eletroquímico de três corantes dispersos, Vermelho Disperso 1, Laranja Disperso 1 e Vermelho Disperso 13 foi investigado em N,N-dimetilformamida usando tetrafluorborato de tetrabutilamônio como eletrólito de suporte. O grupo nitro dos corantes é reduzido em potenciais de -0,85 V, -0,79 V e -0,69 V, respectivamente, para os corantes Vermelho Disperso 1, Laranja Disperso 1 e Vermelho Disperso 13. A oxidação do grupo amino, também presente nos corantes investigados, ocorre, respectivamente, em potencial de 0,95 V, 0,90 V e 1,0 V e promove a clivagem do grupo azo. Devido à toxicidade e mutagenicidade destes corantes, analisada pelos testes de citotoxicidade em células humanas embrionárias HEK293 e de Ames, respectivamente, investigou-se no presente trabalho novos métodos de degradação dos mesmos em meio aquoso usando o agente dispersante comercial “Emulsogen” por meio de tratamento com cloro ativo (cloração convencional) e fotoeletroquimicamente pela geração de radicais cloro “in situ” sobre eletrodos nanoparticulados de Ti/TiO2, preparados pelo método sol-gel, em NaCl 0,1 mol L-1. A oxidação fotoeletrocatalítica, sobre eletrodos nanoparticulados de Ti/TiO2 em NaCl, mostrou-se mais eficiente quando comparada à cloração convencional, tanto na descoloração que promoveu 100% de remoção de cor, quanto na mineralização dos mesmos (até 60% de remoção de COT). A mutagenicidade dos corantes estudados foi drasticamente reduzida após tratamento fotoeletroquímico. No entanto, a cloração convencional não foi eficiente para total remoção da atividade mutagênica dos corantes, observando-se, ainda, um aumento para o corante Vermelho Disperso 13. A degradação também foi investigada sobre eletrodos de nanotubos de Ti/TiO2, preparados pelo método de anodização eletroquímica...
The electrochemical behavior of three disperse dyes, Disperse Red 1, Disperse Orange 1 and Disperse Red 13, was investigated using N,N-dimethylformamide using in tetrabutylammonium tetrafluoroborate as supporting electrolyte. The nitro group of the dyes is reduced in potential of –0.85 V, 0.79 V and –0.69 V, respectively, for Disperse Red 1, Disperse Orange 1 and Disperse Red 13. The oxidation of amine group, also presents in the dyes molecules, occurs, respectively, at 0.95 V, 0.90 V and 1.0 V and promotes cleavage of azo group. Because of these dyes toxicity and mutagenicity, analyzed by citotoxicity in embryonic human cells HEK293 and mutagenicity detected by Ames test, respectively, new methods of degradation of these dyes in aqueous medium using the commercial dispersant agent “Emulsogen” was investigated by active chlorine treatment (conventional chlorination) and photoelectrochemically by “in situ” chlorine radicals generation using Ti/TiO2 nanoparticulates electrodes, prepared by solgel method, in 0.1 mol L-1 NaCl. The photoelectrocatalytic oxidation, using Ti/TiO2 nanoparticulates electrodes in NaCl presented higher efficiency when compared to conventional chlorination, leading to 100% of color removal and also 60% of mineralization of dyes measured as TOC removal. The mutagenicity of all investigated dyes was dramatically reduced after photoelectrochemical treatment. However, the conventional chlorination was not efficient for mutagenic activity removal of dyes and promoted an increase for Disperse Red 13. The degradation was also investigated using Ti/TiO2 nanotubes electrodes, prepared by electrochemical anodization in fluoride medium and characterized by SEM and photocurrent curves. These electrodes presented 100% of discoloration of all investigated dyes and total organic carbon removal around 70% after 3 hours of photoelectrocatalytic degradation... (Complete abstract click electronic access below)
Rudys, Saulius. "Plačiajuostės dielektrinės spektroskopijos metodų tobulinimas, tiriant (1-x)(Na1/2 Bi1/2)TiO3 - xLa(Mg1/2 Ti1/2)O3 ir kitas medžiagas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20121001_093621-49513.
Full textOne of the basic problems in measurements of the electrical properties of materials is finding relations between measured electrical values and characteristics of the material, especially when the field distribution in the device under test with a sample inside is complex. Commercial electromagnetic simulation software was used in unconventional way to calculate materials' electrical properties. Because the software is not adopted for this task, built-in optimisation option was used. In this way dielectric and magnetic properties of materials in very complex shape were calculated. The method was tested by calculation of complex dielectric permittivity of Bi1.5ZnNb1.5O7-xF2 pyrochlore ceramics as well as by calculation of both complex dielectric permittivity and complex dielectric permeability of carbon-coated capsules of Ni embedded into polyurethane matrix from experimental results. Due to the fact that using numerical methods is time consuming, a mathematical model on mode matching approach of rectangular rod in a waveguide and a new model of multimode capacitor were developed. Models were checked by numerical methods. On a high frequency, when electric field in the sample is inhomogeneous, the magnetic field in the sample is much stronger than in the transmission line. Thus, the magnetic permeability of the sample will affect scattering parameters. Based on this circumstance, the method to measure small magnetic permeability using capacitor like in coaxial line when... [to full text]
Wilkening, Martin, and Paul Heitjans. "Ultraslow cation diffusion in Li intercalated cubic TiS 2." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-196145.
Full textWilkening, Martin, and Paul Heitjans. "Ultraslow cation diffusion in Li intercalated cubic TiS 2." Diffusion fundamentals 2 (2005) 60, S. 1-2, 2005. https://ul.qucosa.de/id/qucosa%3A14394.
Full textZhang, Huanjun. "Ag/TiO[subscript 2] nanocomposites : synthesis, characterizations and applications /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CBME%202009%20ZHANGH.
Full textRose, Jamey. "Hydroxylation of 2-methylnaphthalene to 2-methylnaphthoquinone over TI-substituted catalysis." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5192.
Full textENGLISH ABSTRACT: Partially oxygenated aromatic compounds, e.g. quinones, hydroquinones and cresols, play a vital role in the fine chemical industry and were initially prepared by stoichiometric oxidation processes that produce toxic products that are hazardous towards the environment. As a result, it was important to investigate environmentally friendly processes for the hydroxylation of aromatic compounds. This resulted in newer methods using Ti-substituted microporous zeolites as catalysts with hydrogen peroxide as oxidant in the presence of a solvent. However, the methods were found to be ineffective for large, bulky substrates due to the small pore structure. This led to using Ti-mesoporous materials as catalysts but suffered from two drawbacks; the hydrophilic nature and low hydrothermal stability of the catalyst structure. Ti-microporous and Ti-mesoporous materials acting as catalysts for the oxidation of bulky substrates achieved environmentally friendly processes but obtained low conversions and quinone yields. Therefore, the challenge has been to develop a process that is environmentally friendly, achieves high conversions, where the catalyst acts truly heterogeneous and obtains high quinone yields for the hydroxylation of bulky substrates. Recently, micropores/mesopores catalysts incorporating advantages of both micropores and mesopores materials were synthesised and seemed promising for the hydroxylation of bulky substrates. This study focuses on synthesising and evaluating the feasibility of various Ti-substituted catalysts for improving the hydroxylation of the bulky substrate, 2-methylnaphthalene (2MN) with hydrogen peroxide as oxidant in the presence of a solvent, acetonitrile. The oxidation of 2MN produces 2-methyl-1,4-naphthoquinone (2MNQ). 2MNQ is also known as menadione or Vitamin K3 and acts as a blood coagulating agent. The catalysts synthesised for this study were mesoporous catalysts, Ti- MCM-41 and Ti-MMM-2 and microporous/mesoporous catalysts, Ti-MMM-2(P123) and a highly ordered mesoporous material. The main objective of this study was to design an efficient process that is environmentally friendly and achieves high 2MN conversions and 2MNQ yields. This was achieved by evaluating the various catalysts synthesised, reaction conditions, testing if the catalyst was truly heterogeneous and identifying the products formed from the process. The designed process was proved to be environmentally friendly because the system did not produce products that were harmful towards the environment. The products identified in this study were 2MNQ, 2-methyl-1-naphthol, 2-naphthaldehyde, 3-ethoxy-4-methoxybenzaldehyde and menadione epoxide. An investigation was conducted to determine which catalyst synthesised favoured this process by quantifying the effect reaction conditions have on the various catalysts. The reaction conditions were defined in terms of the hydrogen peroxide volume, catalyst amount, solvent volume, substrate amount, reaction time and reaction temperature. The desired catalyst for this study obtained the highest 2MN conversions in comparison with the other catalysts and favoured the formation of 2MNQ. The catalyst achieving the highest conversions and favouring 2MNQ in most cases for this investigation was the highly ordered mesoporous material. Improving operating conditions to obtain high 2MNQ yields for the oxidation of 2MN to 2MNQ over the highly ordered mesoporous material was determined by varying the reaction conditions with the one factor at a time approach and a factorial design. The one factor at a time approach showed that best 2MNQ yields were obtained at 1 g substrate when investigating a change in substrate amount between 0.5 g and 2 g. Best 2MNQ yields were obtained at 10 ml solvent when investigating a change of solvent volume between 5 ml and 20 ml. The 2MNQ yield increased with increasing the catalyst amount (50 mg to 200 mg), hydrogen peroxide volume (1 ml to 6 ml) and increasing the reaction times (2 hour to 6 hours) at reaction temperatures, 120°C and 150°C. The yield decreased with increasing the reaction time (2 hours to 6 hours) at reaction temperature, 180°C. A preliminary 2 level factorial design was prepared to observe if there were any important interactions affecting the 2MNQ yield. The results from the factorial design indicated that the hydrogen peroxide volume had the most influence on the 2MNQ yield followed by the reaction time-reaction temperature interaction and reaction temperature. From the factorial design, the yield increased by increasing the hydrogen peroxide volume and reaction temperature whilst decreasing the reaction temperature-reaction time interaction. The highest 2MNQ yields and 2MN conversions obtained for the hydroxylation of 2MN to 2MNQ over the highly ordered mesoporous material in this study were in the ranges 48-50 % and 97-99 %, respectively. This study indicates that the process system, reaction conditions and catalyst type have an impact on the products formed, 2MN conversion, 2MNQ selectivity and 2MNQ yield. The highly ordered mesoporous material was found to be truly heterogeneous because no leaching occurred and the catalyst could be recycled without losing its catalytic activity and selectivity for at least two catalyst cycles. It can be concluded that the highly ordered mesoporous material is therefore a promising catalyst for the selective oxidation of bulky substrates with aqueous H2O2 because it produces an environmentally friendly process, achieves high conversions, obtains high quinone yields and the catalyst truly acts heterogeneous.
AFRIKAANSE OPSOMMING: Gedeeltelik geoksideerde aromatiese verbindings (bv. kinone, hidrokinone en kresole) speel ‘n belangrike rol in die fynchemiebedryf. Hierdie verbindings is aanvanklik voorberei deur stoïchiometriese oksidasie prosesse wat gifstowwe nadelig vir die omgewing veroorsaak. Daarom is dit belangrik om omgewingsvriendelike prosesse vir die hidroksilering van aromatiese verbindings te ondersoek. Hierdie ondersoeke het gelei tot nuwe metodes wat Ti-vervangde mikroporeuse seoliete as katalisator met waterstofperoksied as oksideermiddel in die teenwoordigheid van ʼn oplosmiddel benut. Dit is egter gevind dat hierdie metodes oneffektief is vir groot, lywige substrate weens die fyn poriestruktuur van die katalisator. Dit lei tot die gebruik van Ti-mesoporeuse materiale as katalisators, maar toon twee tekortkominge, naamlik die hidrofiliese aard en lae hidrotermiese stabiliteit van die katalisatorstruktuur. Ti-mikroporeuse en Ti-mesoporeuse materiale benut as katalisators vir die oksidasie van lywige substrate lewer omgewingsvriendelike prosesse, maar vermag lae omsetting en kinoonopbrengs. ʼn Uitdaging is dus om ʼn omgewingsvriendelike proses te ontwikkel met hoë omsetting, waar die katalisator werklik heterogeen optree en hoë kinoonopbrengs lewer vir die hidroksilering van lywige substrate. Katalisators vir die hidroksilering van lywige substrate wat die voordele van beide mikroporieë/mesoporieë ten toon stel is onlangs gesintetiseer, met belowende resultate. Hierdie studie is ingestel op die sintetisering en evaluering van uitvoerbaarheid van verskeie Tivervangde katalisators vir die optimering van die hidroksilering van die lywige substraat, 2- metielnaftaleen (2MN), met waterstofperoksied as oksideermiddel met asetonitriel as oplosmiddel. Die oksidering van 2MN produseer 2-metiel-1,4-naftokinoon (2MNK), ook bekend as vitamien K3, ʼn bloedstollingsmiddel. Die katalisators vervaardig vir hierdie studie was die mesoporeuse katalisators, Ti-MCM-41 en Ti-MMM-2, en die mikroporeuse/mesoporeuse katalisor Ti-MMM-2(P123), sowel as ʼn hoogs geordende mesoporeuse materiaal. Die hoofdoel van hierdie studie was om ʼn doeltreffende, omgewingsvriendelike proses met hoë 2MN omsetting en 2MNK opbrengs te ontwerp. Voorgenoemde is vermag deur verskeie gesintetiseerde katalisators en reaksiekondisies te evalueer, om te toets of katalisators werklik heterogeen is, en om die prosesprodukte te identifiseer. Die ontwerpte proses kan beskou word as omgewingsvriendelik, aangesien die stelsel geen produkte lewer wat skade aan die natuur kan veroorsaak nie. 2MNK, 2-metiel-1-naftol, 2-naftaldehied, 3- etoksi-4-metoksibensaldehied en menadioonepoksied is in hierdie studie geïdentifiseer as prosesprodukte. Om te bepaal watter gesintetiseerde katalisators hierdie proses begunstig, is ʼn ondersoek geloods om die effek van reaksiekondisies op die verskeie katalisators te kwantifiseer. Die reaksiekondisies is omskryf in terme van waterstofperoksiedkonsentrasie, katalisatorhoeveelheid, oplosmiddelvolume, substraathoeveelheid, reaksietyd en reaksietemperatuur. Die gewenste katalistor vir hierdie proses was die katalisator wat die hoogste 2MN omsetting lewer en die vorming van 2MNK bevorder. Die hoogs geordende mesoporeuse materiaal was in hierdie ondersoek die katalisator met die hoogste omsetting wat ook 2MNK-vorming bevorder het in die meeste gevalle. Om die beste bedryfstoestande vir hoë 2MNK opbrengs vanaf die oksidering van 2MN oor hoogs geordende mesoporeuse materiaal te bepaal, is die reaksiekondisies verander deur met een faktor op ʼn slag te verander, sowel as faktorverandering volgens ʼn faktoriaalontwerp. Die een-faktor-op-‘nslag benadering het getoon dat die 2MNK opbrengs ʼn maksimum bereik waar die substraathoeveelheid tussen 0.5 g en 2 g wissel, met die oplosmiddelvolume tussen 5 ml en 20 ml. Die opbrengs het ietwat verbeter met ʼn groter hoeveelheid katalisatorhoeveelheid (van 50 mg na 200 mg), terwyl die opbrengs drasties verbeter het waar die waterstofperoksiedvolume van 3 ml tot 6 ml verhoog is. Die opbrengs het ook verbeter met ʼn styging in reaksietemperatuur (van 120°C tot 180°C) met reaksietydintervalle van 1 tot 6 ure. Die opbrengs het egter gedaal by 180°C waar reaksietye langer as 2 ure. Volgens die resultate van die een-faktor-op-‘n-slag benadering blyk dit dat reaksietemperatuur, waterstofperoksiedvolume, katalisatorhoeveelheid en reaksietyd faktore is wat verhoogde 2MNK opbrengs bevorder. Hierdie reaksiekondisies is geselekteer vir die faktoriaalontwerp. ʼn Voorlopige 2- vlak faktoriaalontwerp is voorberei om te bepaal of daar enige belangrike interaksies is wat die 2MNK opbrengs beïnvloed. Die resultate van die faktoriaalontwerp het aangetoon dat waterstofperoksiedvolume die grootste invloed op 2MNK opbrengs het, gevolg deur die interaksie van reaksietyd en reaksietemperatuur, en dan reaksietemperatuur. Die faktoriaalontwerp resultate toon verder dat opbrengs verhoog met toenemende waterstofperoksiedvolume en reaksietemperatuur, terwyl die opbrengs verlaag soos wat die reaksietyd-reaksietemperatuur interaksie toeneem. Hierdie studie het hoogste 2MNK opbrengs van 48-50% en 2MN omsetting van 97-99% vir die hidroksilering van 2MN na 2MNK oor hoogs geordende mesoporeuse materiale behaal. Hierdie studie bevestig bevindinge van die literatuur dat die prosesstelsel, reaksiekondisies en katalisatortipe ʼn groot impak het op prosesprodukte, 2MN omsetting, 2MNK selektiwiteit en 2MNK opbrengs. In hierdie navorsingstudie is bevind dat hoë 2MN omsetting en 2MNK opbrengs behaal word by hoë reaksietemperature met kort reaksietye en hoë waterstofperoksiedvolumes. Dit is gevind dat die hoogs geordende mesoporeuse materiaal werklik heterogeen is, aangesien geen loging plaasgevind het nie, en aangesien die katalisator hergebruik kon word sonder verlies aan katalisatoraktiwiteit en –selektiwiteit, vir ten minste twee katalisatorsiklusse. ʼn Gevolgtrekking kan gemaak word dat die hoogs geordende mesoporeuse materiaal ʼn belowende katalisator vir die selektiewe oksidering van lywige substrate met waterige H2O2 is, aangesien dit ʼn omgewingsvriendelike proses lewer met hoë omsetting, hoë kinoonopbrengs en katalisatorgedrag wat waarlik heterogeen is.
Souza, Aline Friedrichs de. "Expressão das angiopoietinas 1 e 2 e do receptor TIE2 em fígados de pacientes com atresia biliar." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/87171.
Full textBackground- Biliary atresia (BA) is an infantile disorder characterized by progressive sclerosing cholangiopathy leading to biliary obstruction. First line treatment of BA is hepatoporto-enterostomy, whose prognosis is related to age at surgery and to histologic variables such as extent of fibrosis and ductular reaction. Hepatic arterial medial thickening (MT) suggests an arteriopathy in BA pathogenesis. We evaluated the expression of angiopoietin (ANGPT)/tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (Tie2) system in livers from patients with BA, correlating with MT, variables associated with disease severity and postoperative prognosis. Methods- ANGPT1, ANGPT2 and Tie2 expressions were assessed by qPCR in liver samples obtained from BA patients (n=23) at portoenterostomy and age-matched infants with intrahepatic cholestasis (IHC, n=7). Histologic variables were morphometrically assessed. Results- ANGPT1 and ANGPT2 were overexpressed in BA in comparison with IHC (respectively, P=0.024 and P=0.029). In BA, ANGPTs′ expression was positively correlated with MT (ANGPT1:rs=0.59, P=0.013; ANGPT2:rs=0.52, P=0.032), not with variables associated with disease severity. Tie2 and ANGPTs′ expressions were negatively correlated (ANGPT1: rs=-0.73, P<0.001; ANGPT2: rs=- 0.54, P=0.007). Conclusion- In BA there is overexpression of both ANGPT1 and ANGPT2 correlated with MT but not with age at portoenterostomy or with the histological variables associated with disease severity at the procedure.
Popov, A. (Alexey). "TiO2 nanoparticles as UV protectors in skin." Doctoral thesis, University of Oulu, 2008. http://urn.fi/urn:isbn:9789514288982.
Full textLéaustic, Anne. "Nouveaux colloides photosensibles a base d'oxyde de titane tio : :(2)." Paris 6, 1987. http://www.theses.fr/1987PA066110.
Full textKron, Gregor. "Ladungsträgertransport in farbstoffsensibilisierten Solarzellen auf Basis von nanoporösem TiO 2." [S.l. : s.n.], 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10678396.
Full textTucić, Aleksandar. "Wet chemical synthesis and characterization of organic/TiO 2 multilayers." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-34138.
Full textRudys, Saulius. "Development of the methods of broadband dielectric spectroscopy by investigating (1-x)(Na1/2 Bi1/2)TiO3 - xLa(Mg1/2 Ti1/2)O3 and other materials." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20121001_093609-73724.
Full textŠiame darbe nagrinėjamos galimybės patobulinti plačiajuostės dielektrinės spektroskopijos metodus naudojant skaitmeninius ir analitinius daugelio modų dielektrinės skvarbos skaičiavimo metodus, tiriami (1-x)(Na1/2 Bi1/2)TiO3 - xLa(Mg1/2 Ti1/2)O3 (NBT-LMT) keramikų grupės laidumo ypatumai. Nagrinėjama galimybė pritaikyti HFSS skaitmeninio modeliavimo programą dielektrinės spektroskopijos tikslams. Naudojant šią programinę įrangą, apskaičiuojama dielektrinė ir magnetinė skvarbos komplikuotiems mikrojuostelinės linijos ir dalinai užpildyto bangolaidžio matavimo grandinių atvejams. Pateikiami patobulinti kondensatoriaus koaksialinėje linijoje ir ribotų matmenų atviro galo koaksialinės linijos matematiniai modeliai. Šie modeliai patikrinami skaitmeniniu metodu. Naudojant daugiamodį kondensatoriaus modelį, atsižvelgus į magnetinio lauko pasiskirstymą koaksialinėje matavimo grandinėje, pasiūlomas būdas pamatuoti mažai bandinio magnetinei skvarbai, kai dielektrinė skvarba didelė (dešimtim ar šimtais kartų didesnė už magnetinę skvarbą). Atviro galo koaksialinei linijai siūloma keletas kalibravimo būdų, įrenginys bandiniui prispausti prie linijos. Bešvinė NBT-LMT keramika buvo tyrinėjama dielektrinės spektroskopijos metodais. Gauti rezultatai rodo, kad NBT-LMT keramikų grupėje elektriniam laidumui galioja Maerio-Neldelio taisyklė.
Arnés, Novau Xavier. "2-dESOXI-2-IODO-1-TIO-FURANÒSIDS I PIRANÒSIDS. NOUS DADORS DE GLICOSIL PER A LA SÍNTESI ESTEROSELECTIVA DE 2-DESOXI-OLIGOSACÀRIDS." Doctoral thesis, Universitat Rovira i Virgili, 2003. http://hdl.handle.net/10803/9011.
Full textLa necessitat de disposar de mètodes per a Ia construcció eficient i estereoselectiva d'unions glicosídiques continua sent un repte actual que té implicacions molt importants en química mèdica i bioorgànica, les quals fan ús de Ia síntesi química per disposar d'aquests productes i poder investigar en Ia comprensió dels mecanismes biològics i en l'elaboració de nous fàrmacs menys tòxics.
Per altra banda, en el camp dels nucleòsids, alguns 2'-desoxi i 2',3'-didesoxi-nucleòsids són inhibidors de Ia transcriptassa inversa del virus de Ia SIDA, i són habitualment utilitzats en el seu tractament.
En ambdós casos però, Ia falta d'un grup estereodirector adjacent al centre anomèric fa de Ia síntesi de 2-desoxi-glicòsids i 2'-desoxi-nucleòsids un repte sintètic especialment interessant. Tanmateix, l'absència d'un substituent electroatractor en C-2 fa que l'enllaç glicosídic sigui molt més làbil front als medis àcids facilitant ('hidròlisi o l'anomerització.
En aquest context, l'objectiu d'aquest treball és desenvolupar nous mètodes de síntesi estereoselectiva de 2-desoxi-oligosacàrids i nucleòsids a partir de 2-desoxi-2iodo-piranòsids i furanòsids. Aquests dadors de glicosil es pretenen obtenir per ciclació intramolecular i estereoselectiva induïda per iode electròfil de polihidroxipentenilsulfurs, i polihidroxi-hexenilsulfurs. Aquest mètode permetria l'accés a dadors de glicosil dadors amb iode a Ia posició 2 per un procediment que no requereix partir de glicals.
Com a conclusió general podem dir que s'han sintetitzat nous dadors de glicosil de configuració mano i alo. Aquests s'han preparat per ciclació amb I+ de trahidroxi-hexenilsulfurs, els quals es poden obtenir fàcilment per olefinació de pentoses. Per altra banda s'ha preparat 2-fluoro-furanòsids per ciclació d'hidroxi-enolèters emprant reactius de fluor elctròfil.
S'han preparat diferents polihidroxi-alquenilsulfurs seguint dues estratègies sintètiques diferents, partint en tots els casos de productes quirals (2,3-diisopropiliden-D-gliceraldehid, (R)-glicidol, D-arabinosa o D-ribosa). Aquestes estratègies es resumeixen en:
a) Incorporació d'una unitat d 2-fenilsulfanil etè. Emprant PhSCΞCH com a sintó, i posterior reducció amb LiAIH4.
b) Introducció d'una unitat monocarbonada junt amb el grup fenilsulfanil (SPh).
Emprant carbanions en reaccions d'olefinació.
En les reaccions d'olefinació s'ha observat un comportament diferent segons els reactius emprats i les condicions de reacció, però sense diferències segons el sucres de partida. En Ia reacció de Wittig-Horner s'han obtingut els millors resultats amb rendiment superiors al 70% essent I'isòmer E majoritari.
S'ha estudiat les reaccions de ciclació de dihidroxi-pentenilsulfurs de fenil, amb diferents grups protectors, induïda per electròfils de iode, i s'han extret les següents conclusions:
a) La reacció és completament regioselectiva donant Iloc a productes de ciclació endo per tancament del cicle sobre el carboni adjacent a l'àtom de S.
b) Sempre s'obtenen mescles de 1-hidroxi-2-iodo-tetrahidrofurans resultat de les ciclacions 5-endo amb activació del grup SPh, i un tetrahidropirà resultat de Ia ciclació 6-endo.
S'han estudiat les reaccions de ciclació de tetrahidroxi-hexenilsulfurs de fenil induïda per electròfils de iode que han proporcionat 2-iodo-1-tio-glicòsids, i s'han extret les següents conclusions:
a) La ciclació transcorre de forma exclusiva pel camí 6-endo.
b) La ciclació és esteroselectiva quan es parteix d'un únic isòmer E o Z.
c) L'estereoselectivitat de Ia reacció ve governada per un efecte estereoelectrònic que s'anomena efecte "inside-alkoxy".
Els 2-iodo-1-tioglicòsids s'han emprat com a dadors de glicosil en reaccions de glicosidació amb diferents alcohols, Ia qual cosa ha permès obtenir α-mano-2-iodoglicòsids i β-alo-2-iodo-glicòsids amb bons rendiment i excel.lents estereoselectivitats, especialment en Ia sèrie mano.
De Ia mateixa manera s'han preparat hidroxi-enolèters seguint les mateixes estratègies sintètiques abans comentades.
Les reaccions de ciclació d'hidroxi-enolèters amb reactius electròfils de fluor, ha proporcionat els compostos fluorats de ciclació, com va ser el cas d'un 2-etoxi-3-fluoro-tetrahidrofurà, el qual es pot considerar com un 2-fluoro-furanòsid precursor de 2-fluoro-nucleòsids.
En el cas d'existir substítució al.lílica, no s'obté el producte de ciclació sinó d'eliminació d'un grup OBn i hidròlisi de l'enolèter, per donar un aldehid α,β-insaturat.
2-Deoxy and 2,6-dideoxy glycosides are frequently found as single structural elements or, more frequently, as components of oligosaccharides, in antibiotics and anticancer agents such as antracyclines (cyclamicine 0), active antibiotics (erytromicines, angucyclines) and pharmacological compounds used in cardiac insufficiency treatment (cardiac glycosides such as digitoxine), etc.
Therefore, methods for the efficient and stereoselective construction of deoxyglycosidic linkages will have useful applications in medicinal and bioorganic chemistry by allowing to understand biological mechanisms and elaborate new and less toxic drugs.
On the other hand, in the nucleoside field, some 2'-deoxy and 2',3'-dideoxy-nucleosides are inhibitors of inverse transcriptase of AIDS virus, and they are often used in its treatment.
In two cases, the lack of a stereodirecting neighbouring group adjacent to the anomeric center makes 2-deoxyglycoside synthesis a particular challenge. Moreover, the absence of electron-withdrawing substituent at C-2 makes the glycosidic bond much more acid labile, giving rise to easy hydrolysis or anomerization.
In this context, the goal of this work is develop new synthetic methods for the stereoselective synthesis of 2-deoxy-oligosaccharides and nucleosides starting from 2-deoxy-2-iodo-pyranosides and furanosides. These glycosil donors are trying to obtain by intramolecular and stereoselective cyclization induced by electrophilic iodine and starting from polihydroxi-pentenylsulfides and polihydroxi-hexenylsulfides as substrates. This method would allow to prepare glycosil donors with iodine at position 2 by means of a procedure that does not require the use of glycals.
It has been prepared different polihydroxi-alkenylsulfides following two different synthetic strategies, starting from quiral products in all cases (2,3-diisopropiliden-D-glyceraldehide, (R)-glycidol, D-arabinose o D-ribose). These strategies are summarized:
a) 2-Fenilsulfanil ethene unit incorporation. Using PhSCΞCH as sinthon, and after LiAIH4 alkyne reduction.
b) Introduction of a monocarbonated unit together the fenilsulfanil group (SPh). Using carbanions in olefination reactions.
In olefination reactions it has been observed a different behaviour depending on the reagents used and the reaction conditions, but without differences depending on the starting sugar. In Wittig-Horner reaction, it has been obtained the best results, yields over 70% for the majority E isomer.
It has been studied cyclization reactions of phenyl dihidroxy-pentenylsulfydes, with different protecting groups, induced by iodine electrophiles, and the conclusions are:
a) The reaction is completely regioselective giving endo cyclization products by closing the cycle over the carbon which is adjacent to sulphur atom.
b) Cyclization reaction is quimioselective, and it's always obtained 1-hydroxi-2iodo-tetrahydrofuranes mixtures by means of 5-endo cyclizations and SPh group activation, and a tetrahydropyrane by mans of 6-endo cyclization.
It has been studied cyclization reactions of phenyl tetra hydroxi-hexenylsuIfides induced by iodine electrophiles that have provided 2-iodo-1-thio-glycosides, and the conclusions are:
a) The cyclization takes place exclusively trough 6-endo path.
b) The cyclization is steroselective starting from one isomer E or Z.
c) The stereoselectivity of the reaction is governed by a stereoelectronic effect
called "inside-alkoxy".
d) It's very difficult to avoid the SPh group activation on the obtained thioglicosydes.
2-lodo-1-thioglicosides has been used as a glycosil donors in glycosidation reactions with different alcohols. That has allowed to obtain a-manno-2-iodo-glycosides and β-alo-2-iodo-glycosides with good yields and excellent stereoselectivities, specially on the manno derivatives.
By the same way it has been prepared hydroxi-enolethers following the same synthetic strategies.
The cyclization reactions of hydroxi-enolethers with fluorine electrophilic reagents has provided fluorinated compounds, such as a 2-ethoxy-3-fluoro-tetrahydrofurane, which could be assembled as a 2-fluoro-furanoside precursor of 2-fluoro-nucleosides.
In the case of hydroxi-enolethers with alilic substitution, it's not obtained the cyclated product, but an α,β-insaturat product is obtained as a result of an OBn group elimination.
Dobeš, Ondřej. "Popis únavového chování UFG Ti pro biomedicínské aplikace." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400500.
Full textSun, Bo. "Understanding and Modifying TiO2 for Aqueous Organic Photodegradation." Cincinnati, Ohio : University of Cincinnati, 2005. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin112361662.
Full textTitle from electronic thesis title page (viewed Apr. 12, 2006). Includes abstract. Keywords: band structure; charge separation; 4-chlorophenol; CrO3; deactivation; Degussa P25; Electrospinning; environment decontamination.; Fibers; MCM-41; MCM-48; Mesoporous Molecular Sieves; oxidation state; photocatalysis; platinum; quantum efficiency; reactivation; reduction; SBA-15; surface modification; synergism; synergy; TiO2; titania; Titanium Dioxide; total carbon removal.; total organic carbon; TPR; Transition metals; visible light; UV-light; UV-Visible. Includes bibliographical references.
Seel, Jennifer A. "Ion-surface scattering measurements of the (110) surface of TiO¦2." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq20951.pdf.
Full textBrandt, Michael Adam. "Studies towards the TiO¦2 mediated photocatalytic oxidative destruction of glutaraldehyde." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ30673.pdf.
Full textMiddleton, Jennifer Elizabeth. "An Anti-Tumour DNA Vaccine Targeting the Endothelial Antigen Tie-2." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519418.
Full textFreitas, Jilian Nei de. "Modulo de celulas solares de TiO/2 corante e eletrolito polimerico." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248622.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Investigaram-se células solares de TiO2/corante e eletrólito polimérico visando a construção de um módulo de 9 V. O filme de TiO2 depositado sobre substratos de FTO (fIuorine tin oxide) em vidro foi obtido a partir da modificação de uma suspensão comercial do óxido coloidal em água. Para obter um filme com bom desempenho, utilizou-se uma suspensão com 0,45 g mL à qual foi adicionado 33 % (m/m) de polietilenoglicol com massa molar 20000. O eletrólito empregado nas células consistiu de Nal e I2 dissolvidos em poli(óxido de etileno-co-epicloridrina) contendo os co-monômeros na proporção 87:13, respectivamente. A condutividade iônica máxima desse sistema ocorreu para uma concentração de sal de 15 % (m/m) em relação à matriz polimérica; 2,7 x 10 S cm sob umidade < 1,0 ppm e ~ 30°C. Com o objetivo de aumentar a condutividade iônica, adicionou-se g-butirolactona como plastificante, mantendo-se a concentração de sal em relação à massa de polímero. Observou-se um aumento de cerca de uma ordem de grandeza na condutividade iônica e no coeficiente de difusão das espécies eletroativas no eletrólito plastificado. A suspensão de TiO2 e o eletrólito otimizados foram utilizados na preparação de células solares com área ativa de 1,0 e 4,5 cm. As células menores foram irradiadas com uma lâmpada de Xe. Sob 10 mW cm foram obtidas eficiências de conversão de energia de 2-3 %. As células com área ativa maior foram caracterizadas diretamente sob o Sol e apresentaram eficiência média de 0,9 % (às 12 h). Estes dispositivos foram usados na montagem de módulos de16 células conectadas em série, produzindo 9 V de potencial e 183 mW (valor integrado em um dia). Em conclusão este trabalho demonstrou que, é possível construir um módulo com células solares de TiO2/corante preparadas com eletrólito polimérico plastificado. O desempenho do módulo excedeu as expectativas, sendo a estabilidade o principal desafio para permitir a sua futura aplicação em escala comercial.
Abstract: TiO2 dye-sensitized solar cells assembled with polymer electrolyte were investigated aiming at the construction of a 9 V module. The TiO2 film deposited on substrates of FTO (fluorine tin oxide) on glass was obtained through the modification of a colloidal oxide suspension in water . To obtain a film with good performance, a suspension containing 0.45 g mL of TiO2 and 33 wt % of polyethyleneglycol with molar weight of 20000 was employed. The electrolyte consisted of Nal and I2 dissolved in poly(ethylene oxide-co-epichlorydrin) containing the monomers in the molar ratio 87:13. The maximum ionic conductivity for this system occurred for a concentration of salt of 15 wt % in relation to the polymer matrix; 2.7 x 10 S cm under relative humidity lower than 1.0 ppm and 30°C. To increase the ionic conductivity, g-butyrolactone was added to the electrolyte as a plasticizer, maintaining the salt concentration constant in relation to the polymer. The measured ionic conductivity and diffusion coefficient for the plasticized electrolyte were both increased by ca. one order of magnitude. Both, optimized TiO2 suspension and electrolyte, were applied in solar cells assembled with active area of 1.0 or 4.5 cm. The smaller cells were investigated under 10 mW cm irradiation, with a Xe lamp, and the efficiency of energy conversion was 23 %. The larger cells were characterized directly under the Sun with an average efficiency of 0.9 % (at 12:00 h). These were used to assemble a 9 V module by connecting in series 16 cells. The integrated average daily power was 183 mW. In summary, this work demonstrated that it is feasible to assemble a module with dyesensitized solar cells employing a plasticized polymer electrolyte. The performance of the modules exceeded all expectations and their stability is the main challenge to allow a future commercial scale application.
Mestrado
Quimica Inorganica
Mestre em Química
Maia, Denison Ricardo Justino. "Embranquecimento de peças injetadas de polipropileno isotatico contendo 'TIO IND.2'." [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248629.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Mestrado
GONCALVES, ANDRE. "Obtencao e caracterizacao de revestimentos compostos de multicamadas TiOsub(2)/TiN." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9572.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Jia, Huiying. "Anodized TiO2 Nanotube Film For Controllable Drug Delivery." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1376435848.
Full textWinde, Christian. "Herstellung und Charakterisierung von Cr-Schichten auf TiO 2 (110)-Oberflächen." [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10069773.
Full textYang, Chi-Ta. "Interplays of CO2, Subnanometer Metal Clusters, and TiO2: Implications for Catalysis and CO2 Photoreduction." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5805.
Full textGehrke, Tim Verfasser], and Thomas [Akademischer Betreuer] [Carell. "Untersuchungen zum Replikationsverhalten carbozyklischer Analoga der Formamidopyrimidine des 2'-Desoxyadenosin und 2'-Desoxyguanosin / Tim Gehrke. Betreuer: Thomas Carell." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2012. http://d-nb.info/1025046994/34.
Full textGehrke, Tim Herbert [Verfasser], and Thomas [Akademischer Betreuer] Carell. "Untersuchungen zum Replikationsverhalten carbozyklischer Analoga der Formamidopyrimidine des 2'-Desoxyadenosin und 2'-Desoxyguanosin / Tim Gehrke. Betreuer: Thomas Carell." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-145981.
Full textPegler, Guilherme Francisco [UNESP]. "'Ti''O IND.2'/'Sn''O IND. 2 modificado com 'Ag IND. 2''O', para obtenção de fotocatalisadores." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/87968.
Full textPelo presente trabalho foram obtidos fotocatalisadores formados por composições binárias e ternárias dos óxidos comerciais TiO2 anatase (marca Synth), SnO2 rutilo (marca Cesbra) e Ag2O (marca Vetec). Anteriormente à preparação dos materiais ternários houve a preparação e estudo de três composições binárias preparadas em três temperaturas distintas de calcinação (400 °C, 600 °C, 800 °C), formadas por TiO2 + SnO2 variando nas razões em porcentagem molar de 25/75, 50/50, 75/25 respectivamente. O material binário TiO2 + SnO2 (75/25 - 400 °C), assim como TiO2 puro foram modificados pela adição de Ag2O nas composições em porcentagem molar de 0,02; 0,1; 0,2 e 1,0. Os materiais foram obtidos pelo método de mistura de óxidos e homogeneização em moinho de bolas rotativo com posterior tratamento térmico à temperatura de 400 °C por 4 horas. Os desempenhos fotocatalíticos desses materiais foram monitorados através de ensaios de descoloração dos corantes orgânicos Rodamina B e Azul de Metileno sob iluminação de luz ultravioleta em reator fotocatalítico desenvolvido neste trabalho. Os picos de absorção molecular dos corantes foram monitorados durante os ensaios fotocatalíticos através de medidas de espectrofotometria UV-vis. Os fotocatalisadores foram caracterizados quanto às fases cristalinas por difração de Raios X, quanto à área superficial específica S(BET) em equipamento de análise de adsorção de N2, quanto à morfologia dos pós por FEG-SEM e quanto à composição química superficial por análise de XPS. Os fotocatalisadores ternários apresentaram cinética reacional superior ao encontrado para o óxido comercial referência TiO2 P25 (marca Degussa) nos ensaios com Rodamina B. Nos ensaios com Azul de Metileno foram obtidos resultados de cinética próximos do encontrado para o óxido...
In this study were obtained photocatalysts consisting of binary and ternary compositions of the commercial oxides TiO2 (Synth), SnO2 (Cesbra) and Ag2O (Vetec). Prior to the preparation of ternary materials there was the preparation and study of three binary compositions prepared in three different calcination temperatures (400 °C, 600 °C, 800 °C) formed by TiO2 + SnO2 ranging in percentage molar ratios of 75/25, 50/50, 75/25 respectively. The binary material TiO2 + SnO2 (75/25 - 400 °C), as well as pure TiO2, has been modified by the addition of Ag2O in 0.02, 0.1, 0.2 and 1.0 molar percentage compositions. The materials were obtained by the oxide mixture technique and homogenization in a rotary ball mill with subsequent thermal treatment at 400 °C for four hours. The photocatalytic performances of these materials were studied by testing of Rhodamine B and Methylene Blue photobleaching under the activation of materials by ultraviolet light in photocatalysis reactor developed in this work. Molecular absorption peaks of the dyes during the tests of photobleaching were monitored by UV-vis spectrophotometry. Crystal structure patterns of the powders were examined by X-ray diffraction (XRD), BET surface area measurement were carried out by using N2 as the adsorptive gas, the morphology analysis were performed by scanning electron microscopy (FEG-SEM) and the elemental chemical composition at the powder surfaces was analysed by XPS analysis. The kinetic analysis showed that the ternary materials had better results than commercial reference oxide TiO2 P25 (Degussa) in the tests with Rhodamine B. When comparing the Methylene Blue performances realized with ternary and TiO2 + Ag2O compositions, the kinetic for both were near the P25. It was also checked photocatalytic activation by sunlight... (Complete abstract click electronic access below)
Pegler, Guilherme Francisco. "'Ti''O IND.2'/'Sn''O IND. 2 modificado com 'Ag IND. 2''O', para obtenção de fotocatalisadores /." Araraquara: [s.n.], 2013. http://hdl.handle.net/11449/87968.
Full textBanca: Rossano Gimenes
Banca: Alberto Adriano Cavalheiro
Resumo: Pelo presente trabalho foram obtidos fotocatalisadores formados por composições binárias e ternárias dos óxidos comerciais TiO2 anatase (marca Synth), SnO2 rutilo (marca Cesbra) e Ag2O (marca Vetec). Anteriormente à preparação dos materiais ternários houve a preparação e estudo de três composições binárias preparadas em três temperaturas distintas de calcinação (400 °C, 600 °C, 800 °C), formadas por TiO2 + SnO2 variando nas razões em porcentagem molar de 25/75, 50/50, 75/25 respectivamente. O material binário TiO2 + SnO2 (75/25 - 400 °C), assim como TiO2 puro foram modificados pela adição de Ag2O nas composições em porcentagem molar de 0,02; 0,1; 0,2 e 1,0. Os materiais foram obtidos pelo método de mistura de óxidos e homogeneização em moinho de bolas rotativo com posterior tratamento térmico à temperatura de 400 °C por 4 horas. Os desempenhos fotocatalíticos desses materiais foram monitorados através de ensaios de descoloração dos corantes orgânicos Rodamina B e Azul de Metileno sob iluminação de luz ultravioleta em reator fotocatalítico desenvolvido neste trabalho. Os picos de absorção molecular dos corantes foram monitorados durante os ensaios fotocatalíticos através de medidas de espectrofotometria UV-vis. Os fotocatalisadores foram caracterizados quanto às fases cristalinas por difração de Raios X, quanto à área superficial específica S(BET) em equipamento de análise de adsorção de N2, quanto à morfologia dos pós por FEG-SEM e quanto à composição química superficial por análise de XPS. Os fotocatalisadores ternários apresentaram cinética reacional superior ao encontrado para o óxido comercial referência TiO2 P25 (marca Degussa) nos ensaios com Rodamina B. Nos ensaios com Azul de Metileno foram obtidos resultados de cinética próximos do encontrado para o óxido... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In this study were obtained photocatalysts consisting of binary and ternary compositions of the commercial oxides TiO2 (Synth), SnO2 (Cesbra) and Ag2O (Vetec). Prior to the preparation of ternary materials there was the preparation and study of three binary compositions prepared in three different calcination temperatures (400 °C, 600 °C, 800 °C) formed by TiO2 + SnO2 ranging in percentage molar ratios of 75/25, 50/50, 75/25 respectively. The binary material TiO2 + SnO2 (75/25 - 400 °C), as well as pure TiO2, has been modified by the addition of Ag2O in 0.02, 0.1, 0.2 and 1.0 molar percentage compositions. The materials were obtained by the oxide mixture technique and homogenization in a rotary ball mill with subsequent thermal treatment at 400 °C for four hours. The photocatalytic performances of these materials were studied by testing of Rhodamine B and Methylene Blue photobleaching under the activation of materials by ultraviolet light in photocatalysis reactor developed in this work. Molecular absorption peaks of the dyes during the tests of photobleaching were monitored by UV-vis spectrophotometry. Crystal structure patterns of the powders were examined by X-ray diffraction (XRD), BET surface area measurement were carried out by using N2 as the adsorptive gas, the morphology analysis were performed by scanning electron microscopy (FEG-SEM) and the elemental chemical composition at the powder surfaces was analysed by XPS analysis. The kinetic analysis showed that the ternary materials had better results than commercial reference oxide TiO2 P25 (Degussa) in the tests with Rhodamine B. When comparing the Methylene Blue performances realized with ternary and TiO2 + Ag2O compositions, the kinetic for both were near the P25. It was also checked photocatalytic activation by sunlight... (Complete abstract click electronic access below)
Mestre
Guaraldo, Thaís Tasso [UNESP]. "Avaliação da performance de eletrodos de filmes finos de Ti/TiO 2 com diferentes tamanhos de nanopartículas na oxidação fotoeletrocatalítica de Índigo Carmim." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/97830.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A nanociência e nanotecnologia são campos científico-tecnológicos empenhados em compreender como o controle estrutural da matéria ao nível molecular pode ser utilizado para a preparação de novos materiais com propriedades únicas e exclusivas. Um material muito promissor para aplicações nanotecnológicas é o dióxido de titânio (TiO2). Este trabalho descreve a síntese e caracterização de semicondutores nanoestruturados de TiO2 na forma de material nanoporoso e nanoparticulado pelo método sol-gel usando o tetra-isopropóxido de titânio [Ti(OPri)4] como precursor, empregados como fotoanodos de Ti/TiO2 no processo de fotoeletrocatálise visando a degradação do corante alimentício Índigo Carmim (IC) utilizado como modelo de poluente orgânico. Tais materiais se diferenciam pela etapa de hidrólise na síntese do sol-gel que foi feita tanto em meio aquoso (nanoporoso) quanto em meio alcoólico (nanoparticulado). Para a preparação dos fotoeletrodos placas de titânio de 25 cm2 foram recobertas com filmes de TiO2 obtidos pelo método sol-gel. A sequência de deposição por dip-coating, lavagem e calcinação a 450 o C por três horas, foi realizada por quatro vezes. A caracterização dos semicondutores nanoestruturados de filmes finos de Ti/TiO2 foi feita por difração de raios-X, microscopia eletrônica de varredura (MEV), microscopia de força atômica (AFM) e assim como caracterização voltamétrica como medidas de fotocorrente versus potencial, potencial de banda plana e determinação de constantes de adsorção. Foi possível determinar o tamanho de partícula de 20 nm o material nanoporoso e 10 nm o nanoparticulado, pela presença das fases anatásio e rutilo uniformemente dispersas, compactas, com alta cristalinidade do TiO2 e conseqüentemente maior fotoatividade. O desempenho do eletrodo nanoparticulado foi notável, principalmente pelo seu menor...
Nanoscience and nanotechnology are scientific-technological fields involved in understanding how structural control of molecular matter level can be used on the preparation of new materials with unique properties. A very promising material for nanotechnology applications is titanium dioxide (TiO2). This work describes the synthesis and characterization of nanostructured TiO2 semiconductor in nanoporous and nanoparticulated materials by the sol-gel method using titanium tetra-isopropoxide [Ti(OPri)4] as a precursor, used as Ti/TiO2 photoanodes in the photoelectrocatalytic process on the degradation of Indigo Carmine (IC) food dye used as a model of organic pollutant. Such materials differ in the hydrolysis step in the sol-gel synthesis that was made in aqueous medium (nanoporous) and in an alcoholic medium (nanoscale).For the preparation of the photoeletrodos titanium foils of 25 cm2 were coated with TiO2 films obtained by the sol-gel method. A sequence of diping, washing and firing at 450 o C for three hours, was performed four times. The characterization of nanostructured Ti/TiO2 semiconductor thin films was made by X-ray powder diffraction (DRX), scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as voltammetric characterization measurements of photocurrent versus potential, flat band potential and determination of adsorption constants. It was possible to determine the particle size of both materials as 20 nm nanoporous and 10 nm nanoparticulated, through the presence of anatase and rutile phases uniformly dispersed, compact, highly TiO2 crystallinity and photoactivity. The best performance of nanoparticulated electrode was notable especially for their smaller particle size and increase in surface area, minimizing the recombination of electron/hole pairs. In photoelectrochemical oxidation the combination of UV irradiation with the application of ... (Complete abstract click electronic access below)
Guaraldo, Thais Tasso. "Avaliação da performance de eletrodos de filmes finos de Ti/TiO 2 com diferentes tamanhos de nanopartículas na oxidação fotoeletrocatalítica de Índigo Carmim /." Araraquara : [s.n.], 2010. http://hdl.handle.net/11449/97830.
Full textAbstract: Nanoscience and nanotechnology are scientific-technological fields involved in understanding how structural control of molecular matter level can be used on the preparation of new materials with unique properties. A very promising material for nanotechnology applications is titanium dioxide (TiO2). This work describes the synthesis and characterization of nanostructured TiO2 semiconductor in nanoporous and nanoparticulated materials by the sol-gel method using titanium tetra-isopropoxide [Ti(OPri)4] as a precursor, used as Ti/TiO2 photoanodes in the photoelectrocatalytic process on the degradation of Indigo Carmine (IC) food dye used as a model of organic pollutant. Such materials differ in the hydrolysis step in the sol-gel synthesis that was made in aqueous medium (nanoporous) and in an alcoholic medium (nanoscale).For the preparation of the photoeletrodos titanium foils of 25 cm2 were coated with TiO2 films obtained by the sol-gel method. A sequence of diping, washing and firing at 450 o C for three hours, was performed four times. The characterization of nanostructured Ti/TiO2 semiconductor thin films was made by X-ray powder diffraction (DRX), scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as voltammetric characterization measurements of photocurrent versus potential, flat band potential and determination of adsorption constants. It was possible to determine the particle size of both materials as 20 nm nanoporous and 10 nm nanoparticulated, through the presence of anatase and rutile phases uniformly dispersed, compact, highly TiO2 crystallinity and photoactivity. The best performance of nanoparticulated electrode was notable especially for their smaller particle size and increase in surface area, minimizing the recombination of electron/hole pairs. In photoelectrochemical oxidation the combination of UV irradiation with the application of ... (Complete abstract click electronic access below)
Orientador: Maria Valnice Boldrin Zanoni
Coorientador: Sandra Helena Pulcinelli
Banca: Christiane de Arruda Rodrigues
Banca: Adalgisa Rodrigues de Andrade
Mestre
Nessim, Christine. "Synthèse des poudres ultrafines de TiO[indice inférieur 2] par plasma inductif." Mémoire, Université de Sherbrooke, 2001. http://savoirs.usherbrooke.ca/handle/11143/1317.
Full textDoeuff, Sylvie. "Elaboration de tio#2 par voie sol-gel : du precurseur au materiau." Paris 6, 1988. http://www.theses.fr/1988PA066210.
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