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Aplica??o de filmes finos de tit?nio em componentes acetabulares de uhmwpe para prote??o contra oxida??o devido a exposi??o ? radia??o XVasconcellos, Let?cia Ara?jo 17 July 2006 (has links)
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Previous issue date: 2006-07-17 / Os implantes de quadril s?o constitu?dos de uma cabe?a esf?rica met?lica que e. g., ? de a?o inoxid?vel 316-L ou ligas de Cr-Co, al?m de um componente polim?rico (UHMWPE). A aplica??o da radia??o gama usada no processo de esteriliza??o e dos raios X de diagn?stico utilizados no controle cl?nico da pr?tese podem contribuir na degrada??o prematura da superf?cie do UHMWPE resultando numa diminui??o do seu tempo de vida ?til. Neste trabalho, foi estudado o grau de prote??o de revestimentos tipo filme fino de tit?nio sobre o componente polim?rico (UHMWPE) em fun??o da exposi??o aos raios X de diagn?stico, comparando-os com os pol?meros n?o revestidos que tamb?m foram expostos ao mesmo tipo de radia??o. Parte destas amostras foram submersas em uma solu??o de HBSS (Hank s Balanced Salt Solution), a qual ? freq?entemente utilizada em culturas de c?lulas, pois simula o meio fisiol?gico do organismo humano. As amostras foram analisadas por diversas t?cnicas de caracteriza??o, dentre elas, a t?cnica de nanodureza para uma an?lise das propriedades mec?nicas do pol?mero, microscopia eletr?nica de varredura (MEV) para observa??o da qualidade superficial do UHMWPE e infravermelho por transformada de Fourier (FTIR) para avalia??o das modifica??es na composi??o qu?mica do pol?mero. Ap?s serem irradiadas, as amostras utilizadas na primeira parte do trabalho, os resultados dos testes de nanodureza levaram a concluir que as propriedades mec?nicas do UHMWPE variam de lote para lote. As an?lises de MEV indicaram dois fatos claros: primeiramente que as amostras revestidas apresentavam uma qualidade superficial com menos danos que as amostras revestidas em concord?ncia com as an?lises de nanodureza e FTIR. Desta forma, com base nos resultados obtidos, podemos concluir que nossa hip?tese inicial, de que uma fina camada de tit?nio pode diminuir a oxida??o superficial do UHMWPE, ? verdadeira.
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Obten??o e caracteriza??o do sistema comp?sito alginato de s?dio-di?xido de tit?nio em formas de p? e de membranaLisboa, Marcia Severiano 28 June 2011 (has links)
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Previous issue date: 2011-06-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The alginates are copolymers of 1→4-linked β-D-mannuronic acid (M) and α-Lguluronic
acid (G) residues that are arranjed in a block structure along a linear chain.
Titanium dioxide, TiO2, is a ceramic material and can exist in three distinct crystallography
forms: anatase, brookite and rutile. composites of organic and inorganic materials have better
properties than the components alone. Thus, this study aims to synthesize, characterize and
analyze the composite NaAlg-TiO2 in the form of powder and film. The synthesis of
composite powders was performed using the sol-gel process and obtain the composite film
was performed using the slow evaporation process, then the composites were analyzed by
infrared spectroscopy, fluorescence x ray, thermal analysis, attenuated total reflection (ATR),
x ray diffraction and impedance spectroscopy. The X ray diffraction patterns of composite
powders show that with increasing calcination temperature, there were no complete transition
of rutile-anatase crystalline phase, since at all temperatures studied (300, 500, 700, 900 and
1100?C) were observed peaks of anatase phase. Thermal analysis shows that at 400?C caused
the decomposition of sodium alginate in sodium carbonate and above 600?C, we observe an
exothermic peak related to the decomposition of sodium carbonate and in the presence of
titanium dioxide becomes sodium titanate. The XRD results confirm the formation of sodium
carbonate at 700?C and the formation sodium titanate in the temperature range 900-1100?C.
The sodium titanate influenced the electrical properties of the material, because with
increasing temperature there was a decrease in conductivity, probably due to the creation of Ti
vacancies, since the sodium can induce the reduction of surface Ti4+ ions into Ti3+ species.
The infrared spectra of the composites in the form of powder and film showed a small shift in
the bands compared to the spectrum of pure alginate, indicating that these shifts, even small
ones, have evidence of miscibility between the polymer and ceramic material / O alginato de s?dio, NaAlg, ? um polissacar?deo formado por liga??es do tipo 1-4
entre os ?cidos β-D-manur?nico e α-L-gulur?nico arranjados em bloco ao longo de uma
cadeia linear. O di?xido de tit?nio, TiO2, ? um material cer?mico e existe em tr?s formas
cristalinas: anat?sio, bruquita e rutilo. Os comp?sitos de materiais org?nicos e inorg?nicos
apresentam melhores propriedades do que os componentes isoladamente. Dessa forma, o
presente trabalho teve objetivo sintetizar, caracterizar e analisar os comp?sitos, NaAlg-TiO2,
em formas de p? e de membrana. A s?ntese dos p?s comp?sitos foi realizada atrav?s do
processo sol-gel e a obten??o dos comp?sitos em forma de membrana foi realizada atrav?s do
processo de evapora??o lenta. Em seguida, os comp?sitos foram caracterizados por
espectroscopia de infravermelho, difratometria de raios X, espectroscopia de imped?ncia,
fluoresc?ncia de raios X, an?lise t?rmica e espectroscopia de reflect?ncia total atenuada-ATR.
Os difratogramas de raios X dos p?s comp?sitos mostraram que, com o aumento da
temperatura de calcina??o, n?o houve a completa transi??o de fase anat?sio-rutilo, uma vez
que, em todas as temperaturas estudadas (300, 500, 700, 900 e 1100?C) foram observados
picos da fase anat?sio. A an?lise t?rmica mostrou que em 400?C ocorreu ? decomposi??o do
alginato de s?dio em carbonato de s?dio e, acima de 600?C, se observa um pico exot?rmico
referente ? decomposi??o do carbonato de s?dio que, na presen?a do di?xido de tit?nio,
transforma-se em titanato de s?dio, confirmados, tamb?m, atrav?s dos difratogramas de raios
X, em que na temperatura de 700?C observa-se picos referentes ao carbonato de s?dio e em
900 e 1100?C picos relacionados ao titanato de s?dio. O titanato de s?dio influenciou nas
propriedades el?tricas do material, pois com o aumento da temperatura houve um decr?scimo
na condutividade, provavelmente, devido ? cria??o de vac?ncias de Ti, uma vez que, o Na+
induz a redu??o dos ?ons Ti+4 para esp?cies Ti+3. Os espectros de infravermelho dos
comp?sitos em formas de p? e de membrana mostraram um pequeno deslocamento nas
bandas, quando comparados ao espectro do alginato de s?dio puro, indicando que estes
deslocamentos, mesmo que pequenos, t?m ind?cios de miscibilidade entre o pol?mero e o
material cer?mico
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FIRM BIDDING BEHAVIOR IN HIGHWAY PROCUREMENT AUCTIONS: AN ANALYSIS OF SINGLE-BID CONTRACTS, TACIT COLLUSION, AND THE FINANCIAL IMPACT ON KENTUCKYBarrus, David R. 01 January 2011 (has links)
Recently, the American Association of State Highway and Transportation Officials (AASHTO) indicated lack of competition and single-bid contracts in asphalt paving as a major issue facing state transportation departments. Single-bid contracts indicate a lack of competition which increases costs to state and local governments. During the period from 2005-2007 in Kentucky, 42 percent of all bids were awarded with only one firm bidding on the project. Of the asphalt paving jobs, 63 percent of those jobs were awarded to a single bidder.
The analysis of this dissertation focuses on detecting tacit collusion in asphalt paving jobs in Kentucky. A focal point enables firms to coordinate bids and engage in a tit-for-tat strategy where they refuse to bid in each other’s counties. In this case the focal point is the county boundaries. Two factors contribute to the ability of firms to use county boundaries to coordinate bids. The first factor is that the political county boundaries form relatively small counties which allow a firm’s service area to cover multiple counties. The firms are able to claim counties and service the projects in those counties. The second factor is that a majority of asphalt projects which the Kentucky Transportation Cabinet puts up for bidding are exclusive to a specific county. This allows firms to know whether a project falls in a county within their bidding territory.
Each county and firm in each of the 12 Kentucky Transportation Cabinet geographic districts was analyzed to see if there was evidence of bid coordination. The result is that in 94 out of 120 counties there was evidence of bid coordination or tacit collusion with increases in bid levels. There is evidence that 25 of the 31 Kentucky asphalt paving firms refuse to bid against their rivals in their rival’s territories. This refusal by firms to bid against each other resulted in single-bid contracts that were $70,595,466.09 above the competitive level.
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Tratamento termoqu?mico do tit?nio auxiliado por plasma de ar - N2 - O2Braz, Danilo Cavalcante 09 June 2011 (has links)
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Previous issue date: 2011-06-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Discs were grade II cp Ti oxynitride by plasma of Ar - N2 - O2 using
different proportions of individual gases. These ratios were established from
analysis of optical emission spectroscopy (OES) of plasma species. The
proportions that resulted in species whose spectra showed an abrupt change of
light intensity were chosen for this study. Nanohardness tests revealed that
there was a correlation between the intensity of N2
+ species with the hardness,
because the treatments where they had a higher intensity, obtained a higher
value nanohardness, although the crystalline phases have remained
unchanged. With respect to topography, it was observed that in general, the
surface roughness is related to the intensities of plasma species, because they
may have different values depending on the behavior of the species. Images
obtained by optical microscopy revealed a surface with grains of different colors
to optical reflectance showed a peak of reflection in the red area. Measures the
contact angle and surface tension showed hydrophilic properties and
hydrophilic with little variation of polar and dispersive components of surface
tension / Discos de tit?nio cp grau II foram oxinitretados por plasma de Ar - N2 - O2
usando diferentes propor??es de gases individuais. Essas propor??es foram
estabelecidas a partir de an?lises de espectroscopia de emiss?o ?ptica (OES)
das esp?cies do plasma. As propor??es que resultaram em espectros cujas
esp?cies apresentaram varia??o abrupta de intensidade luminosa foram
escolhidas para o presente trabalho. Os ensaios de nanodureza revelaram que
houve uma rela??o entre a intensidade da esp?cie N2
+ com a dureza, pois para
os tratamentos onde estas apresentaram maior intensidade, obteve-se maior
valor de nanodureza, embora as fases cristalinas tenham se mantido
inalteradas. Com rela??o ?s topografias, observou-se que de um modo geral, a
rugosidade superficial est? relacionada com as intensidades das esp?cies do
plasma, pois estas podem apresentar valores diferentes dependendo do
comportamento das esp?cies. Imagens obtidas por microscopia ?ptica
revelaram uma superf?cie com gr?os de diferentes cores e a reflet?ncia ?ptica
mostrou um pico m?ximo de reflex?o na regi?o do vermelho. As medidas de
?ngulo de contato e tens?o mostraram superf?cies com propriedades
hidrof?licas e pouco hidrof?licas com varia??o das componentes polar e
dispersiva da tens?o superficial
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Tratamento t?rmico do tit?nio e suas consequ?ncias sobre as propriedades f?sico-qu?micas e de biocompatibilidadeMacedo, Haroldo Reis Alves de 03 February 2012 (has links)
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Previous issue date: 2012-02-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The titanium and titanium alloys are widely used as biomaterial in biomedical device and so research have been developed aiming to improve and/or better to understand interaction biomaterial/biological environment. The process for manufacturing of this titanium implants usually involves a series of thermal and mechanical processes which have consequence on the final product. The heat treatments are usually used to obtain different properties for each application. In order to understand the influence of these treatments on the biological response of the surface, it was done, in this work, different heat treatments in titanium and analyzed their influence on the morphology, adhesion and proliferation of the pre-osteoblastic cells (MC3T3-E1). For such heat-treated titanium disks were characterized by optical microscopy, contact angle, surface energy, roughness, microhardness, X-ray diffraction and scanning through the techniques (BSE, EDS and EBSD). For the analysis of biological response were tested by MTT proliferation, adhesion by crystal violet and β1 integrin expression by flow cytometry. It was found that the presence of a microstructure very orderly, defined by a chemical attack, cells tend to stretch in the same direction of orientation of the material microstructure. When this order does not happen, the most important factor influencing cell proliferation is the residual stress, indicated by the hardness of the material. This way the disks with the highest level state of residual stress also showed increased cell proliferation / O tit?nio e suas ligas s?o amplamente utilizados como biomaterial em dispositivos biom?dicos e devido a isso pesquisas t?m sido desenvolvidas visando aperfei?oar e/ou compreender melhor a intera??o biomaterial/meio biol?gico. O processo de fabrica??o desses dispositivos de tit?nio geralmente envolve uma s?rie de processos t?rmicos e mec?nicos e que t?m consequ?ncias no produto final. Os tratamentos t?rmicos s?o usualmente utilizados para obten??o de propriedades diferenciadas para cada aplica??o. Com o intuito de entender a influ?ncia desses tratamentos sobre a resposta biol?gica da superf?cie, foram realizados, no presente trabalho, diferentes tratamentos t?rmicos em tit?nio e analisadas suas influ?ncias na morfologia, ades?o e prolifera??o de c?lulas pr?-osteobl?stica (MC3T3-E1). Para tanto os discos de tit?nio tratados termicamente foram caracterizados por microscopia ?tica, ?ngulo de contato, energia de superf?cie, rugosidade, microdureza Vickers, difra??o de raios-X e microscopia eletr?nica de varredura atrav?s das t?cnicas de EBS, EDS e EBSD. Para an?lise da resposta biol?gica foram realizados teste de prolifera??o por MTT, ades?o por cristal violeta e express?o da integrina β1 por citometria de fluxo. Foi verificado que na presen?a de uma microestrutura muito ordenada, definida atrav?s de um ataque qu?mico, as c?lulas tendem a se alongar no mesmo sentido da orienta??o microestrutural do material. Quando essa ordem n?o acontece, o fator mais importante a influenciar na prolifera??o celular ? a tens?o residual, indicada pela dureza do material. Deste modo os discos que apresentaram maior estado de tens?o residual apresentaram tamb?m maior prolifera??o celular
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Role sociálního učení při vytváření averze vůči aposematické kořisti u ptačích predátorů / Effect of social learning on avoidance of aposematic prey in avian predatorsBělová, Magdalena January 2018 (has links)
Social learning is a topic of many studies. We tested the effect of social learning on the acquisition of avoidance against aposematic prey. We have chosen wild-caught adult and naive hand-reared juvenile great tits (Parus major) as a model predator species, because their individual avoidance learnig of aposematic prey is well-studied. We used red and green paper dummies of bugs with a mealworm (Tenebrio molitor) stuck underneath as an artificial prey. Mealworms were soaked in water or in bitter-tasting solution of quinine. We used two types of conspecific demonstrators - naive birds that showed aversive reactions while tasting an unpalatable prey and experienced birds that were trained not to handle the unpalatable pray at all. We compared effects of both demonstrators on discrimination learning and we tested whether these effects differ in adult and juvenile birds. Observing an experienced demonstrator had an effect on the performance of observers at the beginning of learning process. The observers did not reject the unpalatable prey completely, but the number of trials in which they correctly chose the palatable prey was higher in comparison with birds that observed naive demonstrators and birds from the control group with no demonstrator. Latencies to handle the unpalatable prey in the first...
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Avalia??o do estresse oxidativo induzido por superf?cies de tit?nioQueiroz, Jana Dara Freires de 29 November 2011 (has links)
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Previous issue date: 2011-11-29 / Commercially pure Titanium (cp Ti) is a material largely used in orthopedic and
dental implants due to its biocompatibility properties. Changes in the surface of
cp Ti can determine the functional response of the cells such as facilitating
implant fixation and stabilization, and increased roughness of the surface has
been shown to improve adhesion and cellular proliferation. Various surface
modification methods have been developed to increase roughness, such as
mechanical, chemical, electrochemical and plasma treatment. An argon plasma
treatment generates a surface that has good mechanical proprieties without
chemical composition modification. Besides the topography, biological
responses to the implant contribute significantly to its success. Oxidative stress
induced by the biomaterials is considered one of the major causes of implant
failure. For this reason the oxidative potential of titanium surfaces subjected to
plasma treatment was evaluated on this work. CHO-k1 cells were cultivated on
smooth or roughed Ti disks, and after three days, the redox balance was
investigated measuring reactive oxygen species (ROS) generation, total
antioxidant capacity and biomarkers of ROS attack. The results showed cells
grown on titanium surfaces are subjected to intracellular oxidative stress due to
hydrogen peroxide generation. Titanium discs subjected to the plasma
treatment induced less oxidative stress than the untreated ones, which resulted
in improved cellular ability. Our data suggest that plasma treated titanium may
be a more biocompatible biomaterial. / O Tit?nio comercialmente puro (cpTi) ? amplamente utilizado em implantes
ortop?dicos e dentais gra?as ?s suas propriedades f?sico-qu?micas. Mudan?as
na superf?cie do cpTi podem determinar respostas funcionais nas c?lulas
influenciando a fixa??o e estabiliza??o do implante. Muitos m?todos de
modifica??o na superf?cie podem ser aplicados para aumentar a rugosidade
como, por exemplo, tratamentos mec?nicos, qu?micos, eletroqu?micos e a
plasma. Este ?ltimo, quando realizado em atmosfera de arg?nio gera uma
superf?cie rugosa com boas propriedades mec?nicas sem alterar a composi??o
qu?mica do material. Superf?cies rugosas geralmente s?o mais biocompat?veis
que as lisas, pois esse tipo de topografia facilita os processos de ades?o e
prolifera??o celular. Al?m da topografia, as rea??es biol?gicas desencadeadas
em resposta ao implante contribuem de forma significativa para o sucesso do
mesmo. Dentre estas rea??es, o estresse oxidativo tem sido apontado como
um dos principais respons?veis por falhas na implanta??o. Diante do exposto, o
potencial oxidativo das superf?cies de tit?nio tratadas e n?o tratadas a plasma
em atmosfera de arg?nio foi avaliado neste trabalho. Para tanto, c?lulas CHOk1
foram cultivadas sobre as superf?cies de tit?nio (tratadas e n?o tratadas).
Ap?s tr?s dias de cultivo o potencial oxidativo foi investigado por meio da
quantifica??o de esp?cies reativas, an?lise da capacidade antioxidante e
an?lise de biomarcadores de dano oxidativo (lipoperoxida??o, carbonila??o
prot?ica e oxida??o das bases do DNA). Os resultados obtidos indicam que
ambas as superf?cies de tit?nio induzem estresse oxidativo, sendo o per?xido
de hidrog?nio a principal esp?cie envolvida. O tratamento a plasma reduziu os
danos oxidativos e promoveu melhora na habilidade celular em responder ao
estresse oxidativo. Deste modo, a modifica??o da superf?cie de tit?nio atrav?s
do tratamento a plasma pode ser uma alternativa para a obten??o de um
material com melhor biocompatibilidade. / 2020-01-01
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S?ntese e caracteriza??o de pigmentos nanom?tricos encapsulados pelos m?todos dos precursores polim?ricos, hidrotermal de microondas e co-precipita??o associado ? qu?mica sol-gel convencionalAndrade, Jean Carlos Silva 10 February 2014 (has links)
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Previous issue date: 2014-02-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A demanda por materiais com alta homogeneidade obtidos a temperaturas
relativamente baixas vem alavancando a busca por processos qu?micos substituintes
do m?todo cer?mico convencional. Esse trabalho tem como objetivo a obten??o de
pigmentos nanom?tricos encapsulados (core-shell) a base de TiO2, dopados com
?ons de metais de transi??o (Fe, Co, Ni, Al) atrav?s de 3 (tr?s) m?todos de s?ntese:
precursores polim?ricos (Pechini); hidrotermal de microondas; e co-precipita??o
associado ? qu?mica sol-gel. O estudo foi motivado pela simplicidade, rapidez e
baixo consumo de energia caracter?sticos desses m?todos. Os sistemas de custos
s?o acess?veis, pois que permitem atingir um bom controle da microestrutura, aliada
a elevada pureza, com controle estequiom?trico e de fases permitindo obter
part?culas de tamanho nanom?trico. As propriedades f?sicas, qu?micas, morfol?gicas,
?pticas e estruturais dos materiais obtidos foram analisadas utilizando diferentes
t?cnicas de caracteriza??o de materiais. Os p?s pigmentantes foram testados na
descolora??o e degrada??o utilizando um fotoreator, atrav?s da solu??o do corante
remazol amarelo ouro (RNL), a partir da filtra??o destas, resultando na separa??o da
solu??o filtrante e dos pigmentos, para posterior realiza??o de medidas de UV-Vis.
As diferentes temperaturas de calcina??o adotadas ap?s a obten??o dos p?s, nos
diferentes m?todos foram: 400 ?C a 1000 ?C. Utilizando uma concentra??o fixa de
10% (Fe, Al, Ni, Co) em massa em rela??o ? massa do tit?nio, viabilizando
tecnologicamente e economicamente o estudo. Atrav?s da t?cnica de microscopia
eletr?nica de transmiss?o (MET) foi poss?vel analisar e confirmar a forma??o
estrutural das part?culas de pigmentos nanom?tricos encapsulados, apresentando
di?metro dos p?s de TiO2 entre 20 nm e 100 nm, e espessura da camada recoberta
de Fe, Ni e Co entre 2 nm e 10 nm. O m?todo de s?ntese mais eficiente entre os
estudados no trabalho foi o co-precipita??o associado ? qu?mica sol-gel, no qual
foram obtidos os melhores resultados, sem a necessidade da obten??o de p?s pelo
processo de calcina??o / The demand for materials with high consistency obtained at relatively low
temperatures has been leveraging the search for chemical processes substituents of
the conventional ceramic method. This paper aims to obtain nanosized pigments
encapsulated (core-shell) the basis of TiO2 doped with transition metals (Fe, Co, Ni,
Al) through three (3) methods of synthesis: polymeric precursors (Pechini);
hydrothermal microwave, and co-precipitation associated with the sol-gel chemistry.
The study was motivated by the simplicity, speed and low power consumption
characteristic of these methods. Systems costs are affordable because they allow
achieving good control of microstructure, combined with high purity, controlled
stoichiometric phases and allowing to obtain particles of nanometer size. The
physical, chemical, morphological, structural and optical properties of the materials
obtained were analyzed using different techniques for materials characterization. The
powder pigments were tested in discoloration and degradation using a photoreactor
through the solution of Remazol yellow dye gold (NNI), such as filtration, resulting in
a separation of solution and the filter pigments available for further UV-Vis
measurements . Different calcination temperatures taken after obtaining the post, the
different methods were: 400 ? C and 1000 ? C. Using a fixed concentration of 10%
(Fe, Al, Ni, Co) mass relative to the mass of titanium technologically and
economically enabling the study. By transmission electron microscopy (TEM)
technique was possible to analyze and confirm the structural formation nanosized
particles of encapsulated pigment, TiO2 having the diameter of 20 nm to 100 nm,
and thickness of coated layer of Fe, Ni and Co between 2 nm and 10 nm. The
method of synthesis more efficient has been studied in the work co-precipitation
associated with sol-gel chemistry, in which the best results were achieved without the
need for the obtainment of powders the calcination process
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Nanorevestindo fibras de PET com TiO2 dopado com metal de transi??o para aplica??o autolimpanteFelipe, Brenno Henrique Silva 19 February 2015 (has links)
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Previous issue date: 2015-02-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O presente projeto visa a s?ntese e caracteriza??o de um nanorevestimento de di?xido de tit?nio dopado com prata em tecido de poli?ster arom?tico, a fim de desenvolver um material t?xtil funcional com aplica??oself-cleaning. Uma t?cnica de deposi??o f?sica de vapor (PVD) foi utilizada como m?todo de s?ntese. A sele??o do material suporte e a t?cnica utilizada na obten??o dos nanorevestimentos s?o vari?veis que podem influenciar nas suas propriedades funcionais, homogeneidade e ades?o. As fibras t?xteis s?o materiais muito empregados como substrato por possu?rem uma maior flexibilidade, serem facilmente adapt?veis a qualquer geometria e baixo custo. A presen?a de Ag e TiO2, bem como sua cristalinidade, foi comprovada atrav?s das an?lises de difra??o de raios X (DRX), espectroscopia fotoeletr?nica de raios-X (XPS) e fluoresc?ncia de raios-x (FRX). A morfologia de superf?cie foi avaliada atrav?s das t?cnicas de microscopia de for?a at?mica (AFM) e microscopia eletr?nica de varredura (MEV). A efici?ncia da atividade fotocatal?tica do material foi comprovada pela descolora??o do corante acid blue 113 em meio a fontes de radia??o UV, com uso da t?cnica de espectroscopia de absor??o (96%). A degrada??o da mol?cula do corante acid blue 113 foi confirmada atrav?s da t?cnica de espectroscopia de infravermelho por transformada de Fourier (FTIR). O car?ter hidrof?bico do nanorevestimento foi confirmado atrav?s da t?cnica de medida de ?ngulo de contato. O car?ter anti UV foi confirmado foi confirmado de acordo com a metodologia normativa AS/NZS 4399:1996. Os resultados comprovam que o material desenvolvido apresenta uma alta capacidade autolimpante, bem como protetora UV. / Innovative methods in the textile segment is currently responsible for increase in production processes, development of new materials and add new technologies in an area that was one of the major participants in the industry revolution. Thus, much research has been responsible for putting the textile industry in the new era of technological revolution watching so, the dynamism of microelectronics companies, food, and mechanics, among others. To this end, this PhD project aims to add value research involving new textile materials. Thus, this project aims to make the synthesis and characterization of a silver doped titanium dioxide nanocoating on polyester fabric in order to develop a functional textile material with self-cleaning application. A physical vapor deposition technique (PVD) was used as the method of synthesis. The selection of the support material and the technique used in obtaining the nanocoatings are variables that can influence their functional properties, uniformity and adhesion. The textile fibers are materials used as substrate by having greater flexibility to be easily adaptable to any geometry and low cost. The efficiency of the photocatalytic activity of the material was confirmed by discoloration of the dye Acid Blue 113 through UV radiation sources, using absorption spectroscopy (96%). The presence of Ag and TiO2 was confirmed by analysis of X-ray diffraction (XRD) photoelectron spectroscopy X-ray (XPS) and x-ray fluorescence (XRF). The surface morphology was evaluated through the techniques of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Degradation of Acid Blue 113 dye molecule was confirmed by infrared spectroscopy Fourier transform (FTIR). The hydrophobic character of nanocoating was confirmed by contact angle measurement technique. The results show that the developed material has a high capacity self-cleaning pro perties
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An?lise citogen?tica de c?lulas-tronco derivadas do subendot?lio da veia umbilical humanaDuarte, Denise de Medeiros 26 February 2009 (has links)
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Previous issue date: 2009-02-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Mesenchymal stem cells (MSCs) are known as a population of multi-potential cells able to proliferate and differentiate into multiple mesodermal tissues including bone, cartilage, muscle, ligament, tendon, fat and stroma. Several applications of the study of EC can be emphasized the therapeutic techniques
such as guided bone regeneration by implantation of EC in the affected site, without the need for bone grafts, using titanium as a vehicle. The process of cryopreservation is essential for the maintenance of cell cultures, since the cell line is frozen, it can be maintained in liquid nitrogen for an indefinite period and then thawed for therapeutic or experimental purposes. The aim of this study was to isolate a population of MSCs derived from the subendothelium of the umbilical vein human (MSCs-SUVH) to assess cytogenetic analysis by the
possibility of appearance of chromosomal changes in two different situations: MSCs-SUVH regarding the process of cryopreservation and MSCs-SUVH grown on the surface of titanium. Flow cytometry analysis revealed that, this cell
population was positive for the markers CD29, CD73 and CD90, but there was no expression of hematopoietic lineage markers, such as CD14, CD34 and CD45 and demonstrated capacity for osteogenic differentiation. The chromosomes obtained from the primary culture of MSCs-SUVH were analyzed by GTW banding technique, and results are described as guidelines to ISCN 2005. There was not the emergence of clonal chromosomal changes in the MSCs-SUVH in different situations analyzed. However one of the strings presented a balanced paracentric inversion, probably a cytogenetic constitutional alterations, which was present before and after the experimental situations that the MSCs-SUVH was submitted / C?lulas-tronco mesenquimais (CTMs) s?o conhecidas como uma popula??o de c?lulas capazes de se proliferar e diferenciar em m?ltiplos tecidos de origem mesod?rmico incluindo osso, cartilagem, m?sculo, ligamento, tend?o, gordura e estroma. Das diversas aplica??es do estudo das CTMs podem-se ressaltar as t?cnicas terap?uticas como a regenera??o ?ssea guiada atrav?s da implanta??o de CTMs no local afetado, sem a necessidade de enxertos ?sseos, usando o tit?nio como ve?culo. O processo de criopreserva??o ? essencial para a manuten??o de cultivos celulares, uma vez que a linhagem celular ? congelada, a mesma pode ser mantida em nitrog?nio l?quido por tempo indeterminado e depois descongelado para fins experimentais ou terap?uticos. Deste modo, o objetivo desse trabalho foi isolar uma popula??o
de c?lulas-tronco mesenquimais derivadas do subendot?lio da veia umbilical humana (CTMs-SVUH) para avaliar atrav?s da an?lise citogen?tica a possibilidade de surgimento de altera??es cromoss?micas em duas diferentes situa??es: CTMs-SVUH frente ao processo de criopreserva??o e CTMs-SVUH cultivadas sobre a superf?cie de tit?nio. An?lise por citometria de fluxo revelou que, esta popula??o celular foi positiva para os marcadores CD29, CD73 e CD90, mas foram negativas para marcadores de linhagem hematopoi?tico
como, CD14, CD34 e CD45 e demonstraram capacidade de diferencia??o osteog?nica. Os cromossomos obtidos a partir da cultura prim?ria de CTMs-SVUH foram analisados atrav?s da t?cnica de bandeamento GTW, e os resultados descritos conforme orienta??es do ISCN 2005. N?o houve o
aparecimento de altera??es cromoss?micas clonais nas CTMs-SVUH nas diferentes situa??es analisadas. Entretanto um dos cord?es apresentou uma invers?o parac?ntrica balanceada, provavelmente uma altera??o citogen?tica constitucional, que esteve presente antes e depois das situa??es experimentais
a que as CTM-SVUH foram submetidas
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