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Desenvolvimento de sensores para imunoensaios aplicados ao diagnóstico do infarto agudo do miocárdioSILVA, Barbara Virginia Mendonca da 24 February 2016 (has links)
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Previous issue date: 2016-02-24 / CAPEs / A presente tese descreve o desenvolvimento de sensores eletroquímicos para
imunoensaios empregando a tecnologia de eletrodos impressos com a finalidade de
detectar a troponina T cardíaca, o marcador mais específico, atualmente, do infarto
agudo do miocárdio. Um dos desafios na confecção de sensores eletroquímicos para
imunoensaios é alcançar baixos limites de detecção. Nanomateriais de carbono são,
recentemente, considerados excelentes estratégias no preparo de superfícies sensoras
devido às suas excelentes propriedades, tais como rápida transferência elétrica e
atividade catalítica, aumento da relação superfície/volume e, consequentemente, maior
quantidade de biomoléculas imobilizadas. Nesta tese, nanotubos de carbono e grafeno
foram utilizados sob diferentes abordagens para modificação de superfícies eletródicas.
Um imunossensor baseado em eletrodos serigrafados obtidos pela impressão de filmes
de nanotubos de carbono amino funcionalizados incorporados em tinta de carbono foi
desenvolvido para detecção “livre de marcação”. Os grupos amino dos nanotubos
expostos na interface sensora impressa foram utilizados para imobilização orientada dos
anticorpos monoclonais anti-troponina T. Os nanofilmes impressos apresentaram uma
excelente estabilidade e reprodutibilidade, exibindo um desvio padrão relativo (DP)
menor que ~2% (n = 8), comparado com controle (DP ~9%, n = 8). A resposta analítica
do sensor, obtida por voltametria de pulso diferencial, apresentou uma faixa linear entre
0,0025 e 0,5 ng/mL de troponina T (r = 0,995; p<0,0001; n=7), combinado a um baixo
erro relativo (<<1%) e limite de detecção de 0,0035 ng/mL. Com o propósito de
substituir os anticorpos anti-troponina T, visto que estes constituem parte onerosa do
dispositivo, um sensor biomimético foi desenvolvido a partir de uma superfície
nanoestruturada de grafeno e polipirrol. A técnica de impressão biomimética em
superfície (“surface imprinting”) foi utilizada como estratégia para simplificar e reduzir
em uma única etapa a produção das cavidades biomiméticas. Estas foram obtidas
através da eletropolimerização do polipirrol e derivados copoliméricos orgânicos
mimetizando grupos proteicos amino-reativos. As respostas analíticas do sensor foram
geradas por voltametria de pulso diferencial, exibindo uma faixa linear de resposta
variando de 0,01 a 0,1 ng/mL de troponina T (r = 0,9953; p<0,0001; n=5) e um limite
de detecção de 0,006 ng/mL, mostrando um ótimo desempenho do sensor biomimético.
As cavidades biomiméticas apresentaram uma constante de dissociação (KD) de 7,3 10-
13 mol/L, indicando boa afinidade à troponina quando comparadas com o sensor
controle (sem troponina T), KD igual a 11,6 10-13 mol/L. Em conclusão, ambas as
plataformas sensoras mostram potencial para detecção da troponina T em níveis de
importância clínica no diagnóstico do infarto agudo, constituindo testes de pronto
atendimento para emergências cardiológicas. / This thesis describes the development of electrochemical sensors for immunoassay by
using a screen-printed electrodes technology in order to detect the human cardiac
troponin T, the most important marker currently of the acute myocardial infarction. One
of the challenges in the manufacturing of electrochemical sensors for immunoassays is
to reach low limits of detection. Carbon nanomaterials are recently considered excellent
strategies in preparing sensing surfaces due to theirs excellent properties, such as rapid
electrical transfer and catalytic activity, increase surface / volume ratio and,
consequently, offering higher amount of immobilized biomolecules. In this thesis,
carbon nanotubes and graphene were used under different approaches in order to modify
the sensors surfaces. An immunosensor based on screen printed electrode obtained by
printing of amino functionalized carbon nanotubes films incorporated into carbon ink
has been developed for "label-free" detection. The amino groups exposed on the
imprinted sensor interface were utilized for oriented immobilization of the monoclonal
antibody anti-troponin T. The imprinted nanofilms showed an excellent stability and
reproducibility, exhibiting a relative standard deviation (RSD) less than ~2% (n = 8)
compared to control (RSD ~9%, n = 8). The analytical response of the sensor, obtained
by differential pulse voltammetry, showed a linear range between 0.0025 and 0.5 ng/mL
(r = 0.995; p <0.0001, n = 7), combined with a low relative error (<< 1 %) and a
calculated limit of detection of 0.0035 ng/mL. In order to replace the anti-troponin T
antibody, since these are costly part of the device, a biomimetic sensor was developed
from a nanostructured surface of graphene and polypyrrole. The biomimetic technique
of surface imprinting was used as a strategy for simplify and reduce in a one-step
production of the biomimetic cavities. These were obtained by electropolymerization of
the pyrrole and its organic copolymers mimicking amino reactive protein groups. The
analytical responses of the sensor were obtained by differential pulse voltammetry,
exhibiting a linear range response in 0.01 and 0.1 ng/mL of troponin T (r = 0.9953; p
<0.0001, n = 5) and a limit of detection of 0.006 ng/mL, showing a good performance
of the biomimetic sensor. The biomimetic sites exhibited a dissociation constant (KD) of
7.3 10-13 mol/L, indicating a good affinity to troponin when compared to its control
(without troponin T), KD equal to 11.6 10-13 mol/L. In conclusion, both sensor platform
the sensor platforms showed a potential for troponin T detection in levels of clinical
important for acute myocardial infarction diagnostic, constituting point-of-care testing
for cardiac emergency departments.
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Desenvolvimento de sensor impresso nanoestruturado modificado com ftalocianina de cobalto para aplicação em ImunossensoresLEITE, Diego Ricardo da Silva 04 February 2016 (has links)
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Previous issue date: 2016-02-04 / CAPES / Atualmente, têm-se buscado métodos que viabilizem um diagnóstico eficaz,
prático, rápido e de baixo custo na detecção de doenças que se revelem atrativos
para os serviços de saúde pública. Nesse contexto, os imunossensores têm
apresentado respostas promissoras, revelando-se como métodos analíticos
práticos, rápidos e econômicos. Recentemente, a utilização de nanomateriais de
alótropos de carbono, destacando-se os nanotubos de carbono (NTC), têm
resultado em melhoria na sensibilidade por aumentar transferência eletrônica,
sobretudo quando aliados a polímeros condutores. O objetivo deste trabalho foi
desenvolver plataforma nanoestruturada para aplicação em imunossensores.
Como objeto de estudo, foi detectado anticorpos contra o nucleocapsídeo do
vírus da hepatite B (HBV), visto que este marcador é o mais importante no
controle e vigilância de bolsas de sangue em serviços hemoterápicos. No
presente trabalho, eletrodos de tinta de carbono serigrafados sobre substrato de
politileno tereftalato (PET) foram modificados por 0,0063% de nanotubos de
carbono (NTC-COOH) e 6% em concentração de ftalocianina de cobalto (CoPc)
que foram recobertos com filmes de polipirrol (PPi). O filme foi obtido por
cronoamperometria (0,8V, 80s) usando soluções de 0,1 M de pirrol (Pi) em meio
ácido. Foi observada uma boa reprodutibilidade e estabilidade dos eletrodos
sobretudo pós-inserção do filme quando caracterizado eletroquimicamente. Além
disso, as imagens de microscopia eletrônica mostraram uma baixa produção de
pirroles. Os sensores desenvolvidos com a associação de nanotubos de carbono
funcionalizados apresentaram melhor desempenho analítico em relação ao
controle (sem NTC). A imobilização do antígeno do núcleo capsídeo da hepatite
B (HBc-Ag) foi confirmada por decréscimo da área eletroativa dos voltamogramas
cíclicos. A resposta aos anticorpos anti-HBc foi evidenciada por técnica de
voltametria de onda quadrada, mostrando que a plataforma desenvolvida é
promissora para aplicação em sensor para hepatite. / Currently, they have been sought methods that enable effective diagnosis,
practical, fast and low-cost in detecting diseases that may prove attractive to
public health services. In this context, immunosensors have shown promising
responses, revealing himself as analytical methods of practical, fast and
economical. Recently, the use of carbon allotropes of nanomaterials, highlighting
carbon nanotubes (CNT), have resulted in improved sensitivity by increasing wire
transfer, especially when combined with conductive polymers. The aim of this
study was to develop nanostructured platform for immunosensors application. As
study object was detected antibodies against the nucleocapsid of hepatitis B virus
(HBV), as this marker is the most important in the control and surveillance of
blood bags in haemotherapic services. In this study, carbon ink electrodes screen
printed on the substrate polythene terephthalate (PET) have been modified for
0.0063% of carbon nanotubes (CNT-COOH) and 6% concentration of cobalt
phthalocyanine (CoPc) were coated with polypyrrole films (PPy). The film was
obtained by chronoamperometry (0.8 V, 80 s) using 0.1 M solution of pyrrole (Py)
in acidic. Was observed a good reproducibility and stability particularly after
insertion of the film electrode when electrochemically characterized. Furthermore,
electron microscopy images showed a low production pyrroles. The sensors
developed in association with functionalized carbon nanotubes showed better
analytical performance compared to the control (without NTC). The immobilization
of the capsid antigen hepatitis B core (HBc-Ag) was confirmed by decreasing the
area of the electroactive cyclic voltammograms. The response to anti-HBc
antibody was evidenced by technical square wave voltammetry, showing that the
platform is developed promising for application to sensor hepatitis.
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Primeiras impressões : romances publicados pela Impressão Regia do Rio de Janeiro (1808-1822) / First impression : novels published by the Impressão Regia do Rio de Janeiro (1808-1822)Souza, Simone Cristina Mendonça de 28 August 2007 (has links)
Orientador: Marcia Azevedo de Abreu / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-09T00:44:01Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007 / Resumo: Dentre os muitos títulos publicados entre 1808 e 1822 na Impressão Régia do Rio de Janeiro, este trabalho se concentra nos romances. Os títulos dos documentos e das obras diversas publicados nesse período foram catalogados ainda no século XIX. Entretanto, boa parte dos exemplares já havia desaparecido, fazendo com que o método utilizado para identificação dos títulos incluísse os anúncios de jornais. Como também eram anunciadas publicações feitas em Lisboa, havia a dúvida quanto à delimitação das que efetivamente foram editadas na Impressão Régia do Rio de Janeiro. A confusão de locais de impressão levantava a hipótese de uma relação editorial entre a Impressão Régia estabelecida na colônia e sua congênere lisboeta. Tal hipótese foi refutada após investigarmos a casa impressora portuguesa e os títulos de romances nela editados. Concluímos que somente seria possível definir quais foram os romances feitos pela primeira casa impressora oficialmente instalada no Brasil com a localização dos exemplares e a confirmação, pelos dados das folhas de rosto, de que foram impressos no Rio de Janeiro. Por meio de buscas, localizamos quase todos os romances catalogados e delimitamos os que saíram dos prelos da Impressão Régia do Rio de Janeiro. No processo, traçamos a história editorial de cada um deles, verificamos de que maneira eram anunciados pelos livreiros nos jornais e analisamos esses livros do ponto de vista material e textual. Raros e de localização trabalhosa, esses romances são atualmente pouco lembrados ou totalmente desconhecidos. No entanto, têm sua importância nos estudos sobre a circulação de livros no período colonial e em anos posteriores e, certamente, fizeram parte da formação do gosto do público por livros do gênero / Abstract: Among many titles published between 1808 and 1822 by Impressão Régia (Royal Printing) from Rio de Janeiro, this thesis concentrates on the novels. In the 19th century the organization of documents and different works published in such period began. However, a significant part of the copies had already disappeared at that time. So, the method used for identifying the titles included newspaper announcements. As publications made in Lisbon were also announced, there was a doubt regarding the delimitation of the ones which had been effectively published by the Impressão Régia from Rio de Janeiro. The confusion about printing places supported the hypothesis about an editorial relation between the Impressão Régia established in the colony and its congener in Lisbon. Such hypothesis was refuted by us after investigating the Portuguese printing house and the titles of novels published by it. We concluded that it would only be possible to define which novels were published by the first printing house officially established in Brazil by means of the localization of the copies and the confirmation, through the data printed on the title page, that they were printed in Rio de Janeiro. We localized almost every novel which were catalogued and delimited those which originated from the press of Impressão Régia from Rio de Janeiro. During the process, we framed the editorial history of each one of them, verify the way they were announced by the booksellers in the newspapers and analyzed these books from the material and textual points view. Being rare and hard to be located, nowadays, these novels are seldom remembered or totally unknown. Nevertheless, they are important for studies about the circulation of books during the colonial period and the subsequent years, and they definitely played an important part in forming the audience's taste for novel reading / Doutorado / Historia e Historiografia Literaria / Doutor em Teoria e História Literária
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Desenvolvimento de células eletroquímicas com impressão 3D e escrita direta em papel para aplicações analíticas e bioanalíticas / Development of electrochemical cells with 3D printing and direct writing on paper for applications analytical and bioanalyticalDias, Anderson Almeida 03 June 2016 (has links)
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Previous issue date: 2016-06-03 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This manuscript describes development of batch injection analysis (BIA) cells
using a 3D printer as well show the fabrication of pencil draw electrode on paper
platform. Bia cells were employed on wall-jet configuration coupled with
amperometric system. Bia systems were used to detect a product reaction
obtained by paper-microreactor and determine ethanol in whiskey samples.
Fabrication process using 3D printer was simple, fast (lower than four hours) and
cost effectiveness (ca. $ 3.43 and 1.07 to the 1st and 2nd generation of Bia system,
respectively). The 1st generation of Bia cell was production to be couple with
commercial screen printed electrodes (SPEs) by DropSens (DropSens, DPR 710
model) and 2nd generation have support to put home-made electrodes. Both Bia
cells, present a specific compartment to be coupled the micropipette. Paperbased
microreactors (MOPs) were used with the 1st generation of Bia cell and the
system was employed to measure glucose through the generation of hydrogen
peroxide by the reaction of glucose with glucose oxidase and amperometric
detection of H2O2 generated in the reaction at a potential of -0.25 V vs. Ag. In the
same way of Bia cell, MOPs fabrication process is simpler, faster and cheaper
(ca. $ 0.02 cent each). In general, the system shows a good linear response for
concentration range between 1 to 10 mmo L-1. The limit of detection (LD) and
quantification (LQ) found were 0.11 mmol L-1 and 0.38 mmol L-1, respectively.
Besides, the measure of glucose using five different MOPs presented a good
repeatability (RSD between 1.5 to 2.8%) and reproducibility (RSD = 0.66%). The
2nd generation of Bia cell was coupled with copper working electrode modified
thermally and chemically. This cell was employed to determine the presence of
ethanol in whisky sample using 1 mol L-1 NaOH as supporting electrolyte and
potential of 0.45 V vs Ag / AgCl. The modified-electrode shows optimum stability
to measure seventy minute of consecutive injection with RSD lower than 4.7%. A
good linear response was obtained when concentration of ethanol ranged from
2.5 to 25% (v/v). The LD achieved was ca. 0.07% (v/v). Besides the Bia cells
experiments, this work describes the fabrication process of alternative electrodes
by hand drawing pencil on paper platform. Initially, the geometry of sensing
electrodes was drawn using a graphic software and printed on paper surface.
During printing process, toner lines were deposited on paper to delimit the
electrode area. Then, the desire layout was draw using a pencil and laminated
using benchtop laminator. This last step is necessary to make the electrical
insulation. Fabrication process of alternative electrodes was simple, fast (~ 20
minutes) and cost effectiveness (ca. $ 0,023). Characterization of paper
electrodes was made by cyclic voltammetry with potassium ferrocyanide
(5 mmol L-1) in KCl solution (0.5 mol L-1). Besides, showed good peak separation
(ΔEp) ca. 238 mV and excellent reproducibility. The RSD was lower than 2.25%
to five different electrodes. / Esta dissertação apresenta o desenvolvimento de células para análise por
injeção em batelada (BIA, do inglês “batch injection analysis”) mediante uso de
uma impressora 3D assim como a fabricação de eletrodos utilizando uma técnica
de escrita direta em papel. As células BIA foram utilizadas com detecção
eletroquímica, visando a análise de um produto de reação realizada em
microrreatores de papel e, também, de etanol em amostras de uísque. As células
BIA, fabricadas no laboratório por meio de uma impressora 3D, apresentaram
baixo custo (cerca de R$ 12,00 e R$ 3,75 para 1° e 2° geração respectivamente),
fabricação rápida (cerca de 4 horas e 1 hora e 40 minutos para 1° e 2° geração
respectivamente) e robustez. Ambas as células BIA foram utilizadas com
detecção amperométrica (DA) e apresentam configuração wall-jet. A 1° geração
BIA possui suporte para eletrodos serigrafados (SPEs) comerciais da DropSens
e pipeta eletrônica e a 2° geração BIA possui suporte para eletrodos
convencionais construídos no laboratório e pipeta eletrônica. Os microrreatores
à base de papel (MOPs) foram vinculados à 1° geração da célula BIA, este
sistema foi utilizado para quantificação de glicose a partir da geração de peróxido
de hidrogênio mediante a reação da glicose com glicose oxidase, e detecção do
H2O2 gerado com SPEs de carbono modificado com azul da prússia (DropSens,
modelo DPR 710) em um potencial de -0,25 V versus Ag. A confecção dos MOPs
é simples, rápida (2 horas e 30 minutos) e de baixo custo (cerca de R$ 0,06 a
unidade). Para a fabricação dos microrreatores a base de papel, primeiramente
foi realizada a modificação química da superfície do papel. Para, em seguida,
efetuar a imobilização covalente da enzima. Os ensaios realizados utilizando os
MOPs vinculados a 1° geração da célula BIA com detecção amperométrica (BIADA)
apresentaram linearidade para faixa de concentração entre 1 e 10 mmol L-1
(R² = 0,990), alta repetitividade (DPR entre 1,5% e 2,8%) e elevada
reprodutibilidade (DPR = 0,66%) para 5 microrreatores. Os limites de detecção
e quantificação obtidos foram de 0,11 mmo L-1 e 0,38 mmol L-1 respectivamente.
A 2° geração da célula BIA foi acoplada com eletrodo de trabalho (ET) de cobre
modificado por tratamento químico / térmico e utilizada para verificação de
adulteração em uísques através da quantificação de etanol utilizando NaOH
1 mol L-1 como eletrólito suporte e potencial de 0,45 V versus Ag/AgCl. Os
ensaios utilizando a 2° geração da célula BIA-DA apresentaram linearidade para
faixa de concentração entre 2,5 e 25 % v/v de etanol (R² = 0,998) e elevada
estabilidade (DPR = 4,7%) para aproximadamente 70 minutos de injeções
consecutivas. O limite de detecção obtido para o etanol foi de 0,07% (v/v). Os
eletrodos em plataforma de papel foram produzidos através da pintura direta com
lápis. Para a fabricação destes dispositivos, primeiramente o layout dos
eletrodos são impressos no papel para definir a área do desenho dos eletrodos.
Em seguida os eletrodos são pintados com lápis, depois os dispositivos são
plastificados com polaseal com o objetivo de isolar os contatos e delimitar a área
dos eletrodos. A confecção destes eletrodos é rápida (~ 20 minutos) e de baixo
custo (R$ 0,082 a unidade). Os eletrodos foram caracterizados utilizando
voltametria cíclica com ferrocianeto de potássio 5 mmol L-1 solubilizado em KCl
0,5 mol L-1. Estes dispositivos apresentaram elevada reprodutibilidade
(DPR = 2,25%) para 5 eletrodos distintos.
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Aplicação de transformação conforme em codificação e decodificação de imagens / Conformal mapping applied to images encoding and decodingSilva, Alan Henrique Ferreira 31 March 2016 (has links)
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Previous issue date: 2016-03-31 / This work proposes method to encode and decode imas using conformal mapping. Conformal mapping modifies domains without modifyung physical characteristics between them. Real images are processed between these domains using encoding keys, also called transforming functions. The advantage of this methodology is the ability to carry the message as an encoded image in printed media for posterior-decoding. / Este trabalho propõe método que utiliza transformações conformes para codificar e decodificar imagens. As transformações conformes modificam os domínios em estudos sem modificar as características físicas entre eles. As imagens reais são transformadas entre estes domínios utilizando chaves, que são funções transformadoras. o diferencial desta metodologia é a capacidade de transportar a mensagem contida na imagem em meio impresso codificado e depois, decodificá-la.
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Os sentidos pluralistas do cotidiano da cultura nas reportagens da revista Realidade nos anos de 1966 a 1968 / Os sentidos pluralistas do cotidiano da cultura nas reportagens da revista Realidade nos anos de 1966 a 1968Marcia Eliane Rosa 22 September 2006 (has links)
Trata-se de uma pesquisa sobre os sentidos da cultura abordados pela revista Realidade nos anos 1966 a 1968. Realidade foi uma publicação de informação geral que teve uma representação singular no jornalismo brasileiro, com um projeto editorial crítico e ousado refletido no processo jornalístico, ao apresentar pautas criadas sob um olhar inquieto frente às mudanças sociais. As reportagens estudadas foram selecionadas de um total de 33 edições publicadas num período de intensas transformações políticas e culturais no Brasil. Neste trabalho, entende-se por cultura manifestações humanas que se estabelecem num processo contínuo e transformador e a qual permite a interação entre as pessoas de uma forma livre e sem hierarquias, estabelecendo relações com diversas áreas do conhecimento. Sob essa proposta, parte-se da hipótese de que a revista capta essa idéia, quando expressa ao leitor as abordagens sociais de maneira pluralizada. Através de leituras de exemplares da Realidade, foi possível notar que as reportagens exercem uma visão ampliada dos acontecimentos culturais, entendendo que a cultura deva ser abordada em todas suas interfaces, mesmo que conflitantes, resistindo a estagnação proposta por regras padronizadas. Nas abordagens estudadas, estão presentes as questões da identidade cultural, dos conflitos gerados pela indústria cultural e as transformações sociais. A imprensa, ao abordar temas culturais no seu histórico de jornalismo cultural tem demonstrado grande superficialidade, com exceção de alguns movimentos particularizados. Assim, esta pesquisa demonstra o jornalismo não estereotipado da revista Realidade que apresenta um enfoque diferenciado e pluralizado para a cultura. / This paper is about a research of the cultural traits handled by Realidade magazine from 1966 to 1968. Realidade magazine was a publication that contained general information, which had a unique representation within the Brazilian news scenario, with a critical and daring editorial project reflected in the journalistic process, by presenting reports created under writers\' restless views, due to the social changes that took place at the time. The news articles studied were selected from a total of 33 issues published during a time of intense political and cultural changes in Brazil. In this work, culture is understood by human manifestations that are established in a continuous and changing process that allows for the interaction among people freely and with no hierarchy, establishing relations with various knowledge areas. Under this proposal, a hypothesis is assumed that the magazine captures this idea, by expressing to the reader social approaches in a pluralized manner. Upon reading Realidade magazine it was possible to observe that the news articles exercise an extended view of cultural events, meaning that culture should be dealt with, in all its interfaces, even conflicting ones, resisting against an stagnation proposed by empty rules. The material studied offers cultural identity issues, conflicts created by the cultural industry and social changes. When treating cultural matters within its journalism history, the press has demonstrated to be very superficial, except in some specific movements. Thus, this research demonstrates that Realidade magazine presents a differentiated and pluralized focus, aimed at culture.
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Gas sensors based on nanostructured tungsten oxidesKukkola, J. (Jarmo) 17 September 2013 (has links)
Abstract
The aim of this thesis is to study whether nanostructured particles of WO3 could be competitive counterparts of traditional, more bulky materials in resistive gas sensor applications. Pristine and various surface decorated derivatives of three different types of WO3 nanoparticles applied on the surface of lithographically defined Si chips were used in the work to analyse the electrical behaviour of thin films when exposed to different gas atmospheres.
Nanosized particles of WO3, obtained by capillary force-induced collapse of porous anodic tungsten oxide in water, were demonstrated as a sensing medium for the detection of H2 and NO analytes. Commercially available nanoparticles of WO3 were also studied. After decorating their surface with metal/metal oxide nanoparticles (Ag, PdOx and PtOx), stable aqueous dispersions were made and used for the inkjet printing of conductive patterns on test chips. Surface decoration was found to affect substantially the gas response behaviour of the materials with the largest differences in response to H2 and NO. The third type of tungsten oxide applied consisted of hydrothermally synthesized nanowires that were also surface decorated with PdO as well as with PtOx. The nanowires were suspended in water and drop cast on test chips for gas sensing measurements. The nanowire based devices allowed ultrasensitive detection of H2 even at room temperature.
The results summarized in this thesis indicate that resistive gas sensors based on nanostructured tungsten oxides are excellent alternatives to existing devices utilizing porous thick films or bulky thin films. Their high sensitivity, low operating temperature and low electrical power consumption may enable the construction of portable sensors, for example by inkjet printing, thus having great potential for fast prototyping but also for large scale production at low cost. / Tiivistelmä
Väitöstyön tavoitteena on tutkia nanorakenteisten WO3 hiukkasten kilpailukykyä suhteessa perinteisiin suuremman kidekoon materiaaleihin resistiivisissä kaasusensorisovelluksissa. Työssä tutkittiin kolmella eri tekniikalla valmistettujen WO3 nanopartikkeleiden alkuperäisistä ja pintakäsitellyistä versioista muodostettujen ohutkalvojen sähköisiä ominaisuuksia erilaisten kaasukehien funktiona.
Veden kapillaarivoimien aikaan saaman huokoisen anodisen volframioksidirakenteen romahduksen kautta saatujen WO3 nanopartikkeleiden osoitettiin toimivan havaintoväliaineena H2 ja NO kaasuille. Myös kaupallisia WO3 nanopartikkeleita tutkittiin. Partikkelien pinta päällystettiin metalli- ja metallioksidinanopartikkeleilla (Ag, PdOx and PtOx), jonka jälkeen niistä muodostettiin vakaita vesipohjaisia seoksia johtavien kuvioiden mustesuihkutulostukseen testisubstraateille. Pintakäsittelyn havaittiin vaikuttavan merkittävästi materiaalien kaasuvasteisiin erityisesti H2:n ja NO:n tapauksessa. Kolmannen tyyppinen väitöskirjassa tutkittu volframioksidimateriaali koostuu hydrotermisesti syntetisoiduista nanojohdoista, jotka ovat pintakäsitelty PdO tai PtOx nanopartikkeleilla. Nanojohdot sekoitettiin veteen ja pipetoitiin testisubstraateille kaasumittauksia varten. Tämän tyyppiset kaasusensorit olivat erityisen herkkiä H2 kaasulle jopa huoneenlämmössä.
Väistökirjan tulosten mukaan nanorakenteiset volframioksidimateriaalit ovat erinomainen vaihtoehto perinteisille huokoisille paksukalvoille ja suhteellisen paksuille ohutkalvoille kaasusensorisovelluksissa. Niiden suuri herkkyys, alhainen toimintalämpötila ja matala sähkönkulutus voivat mahdollistaa kannettavien kaasusensorien valmistuksen, esimerkiksi mustesuihkuteknologilla, nopeaan testaukseen ja suuren mittakaavan tuotantoon alhaisin kustannuksin.
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Inks based on inorganic nanomaterials for printed electronics applicationsNelo, M. (Mikko) 24 November 2015 (has links)
Abstract
In this thesis several novel inks based on dry inorganic powders enabling magnetic, piezoelectric and memory resistive (memristive) function were researched for printed electronics applications.
Low curing temperature screen–printable magnetic inks for high frequency applications based on dry cobalt nanoparticles were developed in the first part of the work. Three publications were achieved. The first one concentrated on ink formulation and its process development, the second on the utilization of multifunctional surfactant, and the third on the development of the inks for plastic substrates. The magnetic inks developed were cured at 120 °C. The electrical performance, microstructure, surface quality and mechanical durability of printed and cured layers were investigated. Relative permeability values up to 3 and related loss tangents up to 0.01 were achieved at 2 GHz frequency, as well as a pull–off strength of up to 5.2 MPa. The maximum loading level of cobalt nanoparticles was 60 vol–%, after which the stability of the ink started to degrade. The developed ink enabled the miniaturization of a patch antenna.
In the second part of the thesis, the formulation of inks based on piezoelectric ceramic particles in powder form with ferroelectric polymers as a matrix material is introduced. The performance and quality of the printed inks and cured layers were investigated. The measured pull off –strength was up to 3.25 MPa, relative permittivity was up to 48 at 1 kHz and piezoelectric constant d31 up to 17 pm/V. The printed piezoelectric layer can be utilized in a pressure sensor.
In the third part of the thesis, the development of inks for a novel printed memory component, a memristor, is researched. A synthesis route was developed for an organometallic precursor solution, which was formulated into inkjet–printable form. The printing tests were carried out in order to find the most feasible layer thickness with memristive behaviour. The influence of substrate materials and different thermal treatments on the components’ electrical properties, durability of read/erase –cycles and overall lifetime were also investigated. The prepared memristive patterns remained functional for up to 35 days, while the precursor solution remained usable for over a year. The memristive areas withstood up to 30 read/erase cycles and by utilizing heat treatments the shift in resistance value increased by up to three orders of magnitude. / Tiivistelmä
Väitöstyössä kehitettiin epäorgaanisten kuivien jauhemaisten materiaalien pohjalta magneettisia, pietsosähköisiä ja memristiivisiä musteita käytettäviksi painettavan elektroniikan sovelluksissa.
Työn ensimmäisessä osassa tutkittiin korkean taajuuden sovelluksissa käytettävien magneettisten, matalassa lämpötilassa kovetettavien, jauhemaisiin kobolttinanopartikkeleihin perustuvien silkkipainomusteiden valmistamista. Tulokset on esitetty kolmessa julkaisussa, joista ensimmäinen keskittyi musteen formulointiin, toinen monifunktionaalisen surfaktantin hyödyntämiseen ja kolmas musteen kehittämiseen muovialustalle sopivaksi. Työssä kehitettiin 120 °C:ssa kovettuvia musteita, joista valmistettujen kalvojen suhteellisen permeabiliteetin maksimiarvoksi saatiin 3 ja häviöiden minimiarvoksi 0,01 kahden gigahertsin taajuudella. Pull–off –vetotestin tulokseksi saatiin jopa 5,2 MPa. Musteet säilyivät vakaina enimmillään 60 tilavuusprosentin metallipitoisuudella. Kehitettyä mustetta käytettiin tasoantennin miniatyrisoinnissa.
Toisessa osassa kehitettiin pietsosähköisiä musteita, jotka pohjautuivat keraamijauheeseen ja matriisimateriaalina toimivaan ferrosähköiseen muoviin. Niistä valmistettujen kalvojen parhaaksi pull off –vetotestin tulokseksi saatiin 3,25 MPa, permittiivisyyden maksimiarvoksi 48 yhden kilohertsin taajuudella ja d31–pietsovakion maksimiarvoksi jopa 17 pm/V. Kehitettyjä painettuja rakenteita voidaan käyttää painettavissa paineantureissa.
Kolmannessa osassa kehitettiin uudentyyppinen painettava muistikomponentti, memristori ja komponenttien valmistamiseksi uusi prekursoriliuoksen synteesi. Syntetisoitu liuos muokattiin mustesuihkutulostettavaksi. Painokokeiden avulla selvitettiin materiaalin paksuus, jolla saatiin aikaan muistivastukselle ominainen memristiivinen käyttäytyminen. Työssä tutkittiin substraattimateriaalien ja mahdollisten lämpökäsittelyjen vaikutusta komponenttien sähköisiin ominaisuuksiin, luku/kirjoitussyklien kestoon sekä käyttöikään. Valmistetut memristiiviset kalvot säilyivät toimivina 35 vuorokautta ja prekursoriliuos yli vuoden. Memristiiviset pinnat kestivät jopa 30 luku/kirjoitussykliä ja vastusarvon muutos saatiin lämpökäsittelyllä kolmea kertaluokkaa suuremmaksi.
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CAD TOOLS FOR HYBRID INTEGRATIONBalakrishnan, Radhakrishnan, Kesavan, Shijith Kunneth January 2015 (has links)
In this thesis, we present a graphical computer-aided design (CAD) environment for the design, analysis and layout of printed electronic batteries in the first phase and the parasitic extraction of the connecting wires in the second phase. The primary motivation of our work is that this prototyping software tool so far does not exist. Our tool has been integrated within the existing CAD tool which allows quick prototyping and simplifies the interface between the system designer and the device manufacturer. This tools supports the schematic and layout entry, rule checking and netlist generation. The first phase of the device synthesis modelling is based on Enfucell printed batteries, by which using the CAD tool, the shape of the battery is optimized and designed to fit the product and is able to simulate the performance during the optimization, whereas the second phase is the parasitic extraction using an extracting tool named fasthenry, which is integrated to our CAD tool to extract unwanted resistance and inductance within the shared wires between the battery and other devices. We believe that the availability of this tool is useful to the CAD community for novel ideas in the circuit design for flexible hybrid electronics. / +46764354255, +46722694942
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Edition et étude littéraire de la version française en prose de la légende d'Ogier le Danois conservée dans les trois premiers imprimés : Lyon, Jean de Vingle (1496) ; Paris, (pour) Antoine Vérard (s.d.) ; Paris, Le Petit Laurens (s.d.) / Edition and literary study of the french prose version of the legend of Ogier le Danois preserved in the three first printed editions : Lyon, Jean de Vingle (1496) ; Paris, (pour) Antoine Vérard (s.d.) ; Paris, Le Petit Laurens (s.d.)Dompierre, Aurélia 20 November 2015 (has links)
Aucun manuscrit d’Ogier le Danois en prose ne nous est parvenu. Nous en conservons néanmoins les trois premiers imprimés : Lyon, Jean de Vingle, 1496 ; Paris, « pour » Antoine Vérard, s.d. ; Paris, Le Petit Laurens, s.d. L’objectif de la thèse est de fournir la première édition critique de cette prose, à partir de l’exemplaire de Paris de l’édition « pour » Vérard, conservé à la BnF. Le texte édité est assorti des variantes offertes par les deux autres témoins, de notes, d’un glossaire détaillé, d’un index des noms propres et d’une liste des expressions proverbiales. La lecture du texte est préparée par une introduction qui traite les points suivants : étude des trois premiers imprimés (description, classement, choix de l’imprimé de base) ; Antoine Vérard ; sources de la prose ; postérité de la prose, à savoir les éditions du XVIe siècle (présentation et classement) et les éditions et traductions ultérieures ; établissement du texte ; étude de la langue (phonétique et graphies, morphologie, syntaxe, lexique), caractéristique du moyen français et marquée par quelques traits dialectaux du Nord et de l’Est ; analyse du texte ; enfin, étude littéraire visant notamment à évaluer le travail de réécriture opéré par le prosateur à partir de sa source (le remaniement en alexandrins daté du milieu du XIVe siècle) et à analyser le style de l’auteur, typique de l’« écriture flamboyante » du XVe siècle. / No manuscript of Ogier le Danois in prose became known to us. However, we conserve the three first printed editions : Lyon, Jean de Vingle, 1496 ; Paris, « pour » Antoine Vérard, s.d. ; Paris, Le Petit Laurens, s.d. The aim of the thesis is to provide the first critical edition of this prose from the exemplary of Paris from Vérard’s edition, preserved in the BnF. The revised text is presented with variants given by the other two printed editions, notes, a glossary, an index of proper nouns and a list of proverbial phrases. The reading of the texte is preparing by an introduction that deals with these following points : study of the three first printed editions (description, classification, selection of one exemplary, revision of the text) ; Antoine Vérard ; prose’s sources ; prose’s posterity with the editions dating from the XVIth century (presentation and classification) and the later editions and traductions ; revision of the text ; linguistic study (phonetic and written forms, morphology, syntax, vocabulary), charactéristic of middle french, with some dialectal traits from the North and the East ; analysis of the story ; finally, literary study aiming in particular at assessing the rewriting work made by the prose writer from the source (the poem in alexandrine dating from the XIVth century) and the style of the author, typical of the flamboyant writing of the XVIth century.
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