Dada sua natureza cursorial, a espécie equina depende da livre movimentação para o desempenho de atividades diárias e para sobrevivência. Esta habilidade natural para o movimento é explorada em alto grau durante a prática esportiva, razão da existência de grande parte dos criatórios e centros de treinamento. Enfermidades articulares, como a osteoartrite e a osteocondrose, que reduzam ou causem prejuízo permanente à mobilidade e ao desempenho atlético são um desafio terapêutico. Os hemoderivados autólogos surgiram como opções acessíveis e seguras para o tratamento destas afecções articulares e apesar de amplamente difundido, seu emprego acontece a despeito de lacunas no conhecimento dos métodos ideais de preparação e administração, bem como dos mecanismos de ação destes produtos derivados do sangue. As propriedades antioxidantes do plasma processado autólogo demonstradas in vitro, em estudo utilizando células de líquido sinovial equino previamente estimuladas, motivaram a realização deste estudo com o objetivo de verificar os efeitos deste hemoderivado, in vivo, em articulações de equinos com osteoartrite ou osteocondrose. Tais propriedades despertaram também o interesse em verificar a ocorrência de eventos relacionados ao estresse oxidativo nestas enfermidades, o que justificaria seu emprego na clínica ortopédica. Para tal fim, líquido sinovial foi obtido antes da abordagem cirúrgica de articulações acometidas pela osteoartrite ou osteocondrose, para análise do perfil oxidante/antioxidante, físico, celular, molecular e inflamatório. Após o término da artroscopia, um grupo de animais recebeu injeção intra-articular do plasma processado autólogo e outro grupo não recebeu nenhuma medicação intra-articular, servindo como controle. Quarenta e oito horas após a cirurgia, nova amostra de líquido sinovial foi coletada, e as mesmas análises foram realizadas. As análises físicas e a contagem de células totais foram realizadas imediatamente após as coletas. O sobrenadante resultante da centrifugação do líquido sinovial foi congelado a -80º C para análises posteriores. Elas consistiram nas dosagens da catalase, superóxido dismutase, glutationa peroxidase, capacidade antioxidante total, vitamina E, proteína carbonil, condroitim sulfato, ácido hialurônico, prostaglandina E2, proteína total e ureia. Em relação à caracterização das enfermidades, as articulações acometidas por osteoartrite apresentaram maiores concentrações de catalase e de vitamina E, refletindo maior ativação dos sistemas de defesa antioxidante enzimáticos e não enzimáticos nesta enfermidade. A osteoartrite apresentou, ainda, natureza mais inflamatória, quando comparada à osteocondrose, com concentrações mais elevadas de prostaglandina E2 e proteína total, além de maiores contagens de células totais no líquido sinovial das articulações afetadas. No entanto, a osteocondrose apresentou caráter mais destrutivo em relação aos componentes da matriz extracelular e do líquido sinovial, com concentrações superiores de condroitim sulfato e ácido hialurônico, respectivamente, no líquido sinovial destas articulações. Os resultados demonstraram a ocorrência de estresse oxidativo no período pós-operatório através da ativação das defesas antioxidantes enzimáticas, com aumento da concentração de catalase. O tratamento com o plasma processado autólogo levou a aumento das concentrações de vitamina E no líquido sinovial, incrementando o sistema de defesa antioxidante não enzimático. Não foram observados efeitos do tratamento sobre o metabolismo da cartilagem articular ou biomarcadores inflamatórios. Pode-se inferir que o plasma processado autólogo apresenta potencial terapêutico no combate ao estresse oxidativo. / As a cursorial animal, the horse relies on soundness to fully accomplish daily life activities and survival. Horses natural ability for movement justifies breeding and training investments, and is explored to its maximum during athletic activities. Articular disorders, such as osteoarthritis and osteochondrosis, with their potential to reduce physical performance, are a therapeutic challenge. Autologous haemoderivates have appeared as safe and accessible options for the management of these conditions, but their widespread use has outpaced scientific evidence regarding mechanisms of action and ideal methods for preparation and administration. The antioxidant properties of autologous processed plasma, previously demonstrated in vitro on stimulated equine synovial fluid cells, posed a question on whether these effects would occur in vivo. Therefore, the present study aimed to verify autologous processed plasma´s effects in osteoarthritic and osteochondritic joints, when administered at the end of the arthroscopic procedure, with particular emphasis on possible antioxidant attributes. The study also aimed to detect evidences of oxidative stress in these disorders, what could further justify its use. For this purpose, synovial fluid was obtained immediately before the beginning of the surgery, and analyzed to yield an oxidant/ antioxidant, physical, cellular, molecular and inflammatory profile of osteoarthritis and osteochondrosis. After the end of the procedure, one group of horses received the intraarticular medication and another group of untreated horses served as controls. Forty-eight hours after surgery synovial fluid was retrieved from operated joints, and a second analysis was performed. Physical and cellular analyses were conducted immediately after sample collection and the supernatant was stored at -80º C for further evaluations. These consisted in catalase, superoxide dismutase, glutathione peroxidase, total antioxidant capacity, vitamin E, protein carbonyl groups, chondroitin sulphate, hyaluronic acid, prostaglandin E2, total protein and urea determinations. Osteoarthritic joints revealed greater activation of antioxidant defense systems, enzymatic and non-enzymatic, with greater activity of catalase, and greater concentrations of vitamin E, respectively, when compared to osteochondritic joints. Additionally, these joints had higher total nucleated cell counts and prostaglandin E2 and total protein concentrations, revealing a more inflammatory profile when compared to that of osteochondritic joints. Nonetheless, in osteochondritic joints synovial fluid and matrix components degradation was more pronounced, as there were higher concentrations of chondroitin sulphate and hyaluronic acid in synovial fluid obtained from these joints. Results also showed the occurrence of oxidative stress, 48 hours after the arthroscopic procedure, through higher catalase activity in synovial fluid, reflecting activation of antioxidant defenses. Treatment with autologous processed plasma increased vitamin E concentrations, incrementing non-enzymatic antioxidant defenses. No effects were observed on metabolic or inflammatory biomarkers. It was possible to infer that autologous processed plasma has the therapeutic potential to lessen oxidative stress effects on articular components in the postoperative period.

nÃo hà / HortaliÃas minimamente processadas (HMP) normalmente consistem de hortaliÃas frescas, cruas, lavadas, descascadas, cortadas, sanitizadas, centrifugadas, empacotadas e acondicionadas sob refrigeraÃÃo. HortaliÃas sÃo potenciais veÃculos de microrganismos que podem estar associadas à doenÃas transmitidas por alimentos. InÃmeras sÃo as causas para a presenÃa de elevada carga microbiana nesse tipo de produto, entre as quais estÃo: as tÃcnicas de cultivo, armazenamento, transporte e distribuiÃÃo para consumo, a prÃtica do uso de adubo orgÃnico, a utilizaÃÃo de Ãgua contaminada para rrigaÃÃo, o transporte realizado em engradados abertos e as condiÃÃes de higiene no manuseio e preparo de refeiÃÃes, principalmente quando tais alimentos sÃo consumidos crus. O objetivo desse estudo foi determinar a presenÃa de Enzimas Betalactamases de Espectro Expandido (ESBL) em cepas de Enterobacteriaceae isoladas de HMP comercializadas na cidade de Fortaleza e verificar se as hortaliÃas analisadas a atendem a RDC N 12 de 02 de janeiro de 2001, que rege o padrÃo microbiolÃgico dos alimentos no Brasil. Foram coletadas 80 amostras de HMP comercializadas em Fortaleza. As hortaliÃas estudadas foram: 8 amostras de acelga; 10 alface; 8 tomate cereja; 8 repolho roxo, repolho verde; 10 cenoura e vagem; 8 cenoura ralada; 10 cenoura ralada, repolho verde e repolho roxo; 10 saladas; 8 coentro, cebola e salsa picados. As anÃlises foram realizadas de abril de 2006 a maio de 2007. As contagens de microrganismos aerÃbios mesÃfilos variaram de 5,60 a 13,35 log UFC/ g de HMP. As contagens de bolores e leveduras variaram de 5,54 a 9,88 log UFC/ g de HMP. A contagem de coliformes totais e coliformes a 45ÂC foram bastante elevadas. O principal bolor isolado e identificado foi o enicillium spp. Todas as amostras de acelga, cenoura ralada, cenoura e vagem, cenoura ralada, repolho roxo e repolho verde, coentro e salsa picados encontravam-se imprÃprias para o consumo, pois apresentaram quantidades superiores a 100 coliformesa 45ÂC/g de amostra. Das amostras de alface 50% apresentavam contagem decoliformes a 45ÂC acima do permitido peÃa legislaÃÃo. Dos tomates cereja analisados 75% estavam dentro padrÃes microbiolÃgicos exigidos pela legislaÃÃo brasileira, para coliforme a 45ÂC. Das amostras de repolho roxo, repolho verde 87% estavam com contagem de coliformes acima do permitido. Das amostras de salada 80% estavam fora dos padrÃes. NÃo foram detectadas Salmonellas nas amostras de HMP analisadas. As principais cepas de Enterobacteriaceae isoladas foram E. coli, K. pneumoniae e E. aerogenes. Todas as cepas de K. pneumoniae e E. aerogenes foram resistentes à ampicilina. Foram detectadas cepas de E. coli, K pneumoniae e E aerogenes com multiresistÃncia aos antibiÃticos testados. NÃo foi observada resistÃncia a ciprofloxacina, ceftazidima e imipenem. NÃo foram detectadas amostras de enterobactÃrias produtoras de ESBL. NÃo foram identificadas cepas de E. coli O15:H7 entre as cepas de E. coli isoladas de HMP. As condiÃÃes higiÃnico-sanitÃrias desses produtos podem ser melhoradas com a aplicaÃÃo de Boas PrÃticas em toda a cadeia produtiva. / Minimally processed vegetables (MPV) normally consist of fresh raw vegetables, washed, peeled, cut, disinfected, centrifugal dryed packed and kept under refrigeration. Vegetables are potential vehicle of microorganisms that can be associated to the outbreaks of foodborne. Countless are the causes for the presence high microbial load in that product type, among which are: the cultivation techniques, storage, transport and distribution for consumption, the practice of the use of organic fertilizer, the use of polluted water for irrigation, the transport accomplished in open crates and the hygiene conditions in the handling and preparation of meals, mainly when such foods are consumed raw. The objective of this study was to determine the presence of extendedspectrum β-betalactamases (ESBL) in strains of Enterobacteriaceae isolated of MPV marketed in the city of Fortaleza and to verify if the analyzed vegetables assists the Brazilian Food Sanitation Standard, RDC N 12, 02 of january 2001. 80 samples of MPV were collected marketed in Fortaleza. Were collected vegetables studied: 8 samples beet; 10 lettuce; 8 of cherry-colored tomato; 8 purple cabbage, green cabbage; 10 carrot and green bean; 8 grated carrot; 10 grated carrot, green cabbage and purple cabbage; 10 salads; 8 cilantro, onion and parsley pricked. The analyses were accomplished of april from 2006 to may of 2007. The countings of mesophiles aerobic, varied from 5,60 to 13,35 log UFC / g of MPV. The countings of moulds and yeasts, varied from 5,54 to 9,88 log UFC / g MPV. The counting of total coliforms and fecal coliforms were quite high. The main isolated and identified mold was the Penicillium spp. All of the beet samples, grated carrot, carrot and green bean, grated carrot, purple cabbage and green cabbage, cilantro and parsley pricked met inappropriate for the consumption, because they presented amounts superior of 100 fecal coliforms / g samples. Of the samples of lettuce 50% they presented fecal coliforms counting above legislation. Of the tomatoes cherry analyzed 75% were inside patterns of the Brazilian legislation, for fecal coliforms. Of the samples of purple cabbage, green cabbage 87% were with fecal coliforms counting above. Of the samples of salad 80% were out of the patterns. Salmonellas were not detected in the samples of MPV analyzed. The main isolated Enterobacteriaceae were E. coli, K. pneumoniae and E. aerogenes. All of the strains of K. pneumoniae and E. aerogenes were resistant to the ampicillin. Strains of E. coli, K pneumoniae and E. aerogenes with multidrug resistance were detected. Resistance to ciprofloxacin, ceftazidime and imipenem was not observed. Enterobacteriaceae samples producing of ESBL were not detected. Were not identified strains of E. coli O15:H7 among the strains of E. coli isolated of MPV. The hygienicsanitary conditions of those products can be improved with the application of Good Practices in the whole productive chain.

In this research, a horror game level was created using ”Unreal Engine 4” (Epic games, 2017) where white noise and processed noises was used as ambiences in order to see how it affects the perceived emotions amongst the participants. A pre-study was conducted in order to choose the stimuli for the main experiment and to test attributes. A pilot test was conducted to test the game level to find out any flaws. In the main experiment twenty participants took part in playing the finalized game level and answering a questionnaire. The results showed a change in the emotional quality depending on the noise being present, but it’s unclear if this is caused by the filtering of the noises alone or the filtering of the noises combined with other factors. A post hoc test was also conducted where a valence and arousal chart was created by letting the participants pin point the emotional attributes used in the experiments.

A ocorrência de surtos de doencas associadas aos vegetais minimamente processados (VMP) tem chamado a atenção para a sua segurança microbiológica. A avaliação quantitativa de riscos permite que o impacto das materias-primas e processamento seja avaliado e os resultados obtidos sejam usados para gestão e comunicação do risco. Desta forma, o presente estudo objetivou quantificar o risco de infecções por Salmonella spp. e Listeria monocytogenes a partir do consumo de VMP no Brasil. Um total de quinhentas e doze amostras de VMP foram analisadas e foi possivel enumerar e detectar Salmonella em 0,4% e 0,4% das amostras, respectivamente. L. monocytogenes foi enumerada e detectada em 0,97% e 3,1% das amostras analisadas, respectivamente. Os isolados de Salmonella spp. (n=4) e L. monocytogenes (n=69) foram confirmados por PCR e caracterizados por sorotipagem tradicional. Os isolados de L. monocytogenes foram caracterizados quanto ao ribotipo, resistencia ao cloro, taxa de multiplicação (µ), capacidade de formação de biofilmes e presença de genes de virulência. O sorovar predominante entre Salmonella spp. foi S. Typhimurium. Em relação a L. monocytogenes, observou-se prevalência do sorotipo 4b e do ribogrupo DUP-1038 e presenca de genes de virulência em 100% (inlA) e 97% (inlC e inlJ) dos isolados. A maioria dos isolados de L. monocytogenes foi resistente a exposição a 125 ppm de cloro livre, e todos foram capazes de aderir ao aco inox, atingindo concentracoes acima de 4 log UFC/cm2. Testes-desafio foram conduzidos para determinar o potencial de multiplicação (δ) de cepas de Salmonella e L. monocytogenes em nove diferentes tipos of VMPs armazenados a 7°C e 15°C por 6 dias. O armazenamento a 15°C por 6 dias resultou nos maiores aumentos nas populações de L. monocytogenes em couve picada (δ= 3,34) e rúcula ((δ= 3,22), enquanto para Salmonella, as maiores populações foram observadas em rúcula (δ= 4,05) e escarola (δ= 2,80). Testes-desafios posteriores indicaram que a multiplicação dos dois patógenos em VMP foi mais pronunciada quando os mesmos foram embalados sob atmosfera modificada em comparação a embalagem em filmes perfurados. Modelos preditivos primários e secundários descrevendo a taxa de multiplicação e tempo de lag de Salmonella spp. e L. monocytogenes em VMP em função da temperatura de armazenamento (7, 10, 15, 20, 25 e 30°C) foram gerados. Verificou-se que os modelos gerados apresentaram a precisão necessária e foram adequados para modelagem da multiplicação dos dois patógenos em VMP. Os modelos de avaliação quantitativa de risco (AQR) foram construidos para determinar a probabilidade de infecção por Salmonella spp. e L. monocytogenes devido ao consumo de VMPs. Os modelos construidos com base nos dados levantados da literatura indicaram risco de infecção por Salmonella spp. e L. monocytogenes de 8.66 x 10-3 e 1.87 x 10-8, respectivamente, sendo necessário que medidas de mitigação do risco sejam adotadas. / The occurrence of foodborne disease outbreaks linked to minimally processed vegetables (MPV) is concerning industries, consumers and governments worldwide. Quantitative risk assessments can estimate the impact of raw materials and processing practices and these estimates are used for risk management and risk communication. This study aimed at quantifying the risks of infection by Salmonella spp. and Listeria monocytogenes due to consumption of MPV in Brazil. A total of five hundred and twelve samples of MPV were analyzed and Salmonella was detected and enumerated in 0.4% and 0.4% of the samples, respectively. L. monocytogenes was enumerated and detected in 0.97% and 3.1% of the samples analyzed, respectively. Isolates of Salmonella spp. (n=4) and L. monocytogenes (n=69) were confirmed through PCR and characterized by traditional serotyping. The isolates of L. monocytogenes were characterized for their ribotype, resistance to chlorine, growth rate, (µ) and ability to form biofilms and presence of virulence factors. Among Salmonella spp., S. Thyphimurium was the most prevalent serovar. Among L. monocytogenes, prevalence of serotype 4b and ribotype DUP-1038 was observed. Virulence gene inlA was present in 100% of the isolates, and genes inlC and inlJ in 97%. The majority of L. monocytogenes isolates were resistant to up to 125 ppm of free chlorine and all isolates were able to attach to stainless steel coupons, reaching populations of up to 4 log10 CFU/cm2. Challenge tests were carried out to determine the growth potential (δ) of Salmonella and L. monocytogenes in nine types of MPV stored at 7°C and 15°C for 6 days. The storage of MPV at 15°C for 6 days resulted in the greatest increases in L. monocytogenes populations in shredded collard green (δ= 3.34) and arugula (δ= 3.22), whereas for Salmonella, the highest populations were found in arugula (δ= 4.05) and escarole (δ= 2.80). Further challenge tests indicated that multiplication of both pathogens in MPV was more pronounced when these products were packaged under modified atmosphere in comparison to packaging in perforated films. Primary and secondary predictive models describing the growth rate and lag time of Salmonella and L. monocytogenes in MPV as a function of storage temperature (7-30°C) were generated. The generated models were accurate and suitable for modeling the growth of pathogens in MPVs. Quantitative risk assessment (QRA) models were built to determine the probability of infection by Salmonella and L. monocytogenes due to consumption of MPVs. The models built using data available in the literature indicated that the risks of infection by these pathogens were 8.66 x 10-3 and 1.87 x 10-8, respectively, evidencing the need for adoption of risk mitigation measures.

L’objectif principal de la thèse était d’étudier les effets de l’alimentation et de l’obésité sur l’asthme et son évolution, en prenant en compte des facteurs de médiations spécifiques.La première partie de la thèse visait à étudier le rôle de l’alimentation dans l'asthme, en prenant en compte l’indice de masse corporelle (IMC) comme un médiateur potentiel, et en évaluant l’effet modificateur du tabac dans ces associations. Ce travail a d’abord porté sur le rôle de la consommation de charcuterie, récemment classée cancérogène. Parmi 971 adultes de l’étude des facteurs génétiques et environnementaux de l’asthme (EGEA), nous avons montré qu’une consommation élevée de charcuterie (au moins 4 fois par semaine) était associée de façon directe à l’aggravation des symptômes de l’asthme, et que seulement 14% de l’association entre la consommation de charcuterie et l’asthme était expliqué par l’IMC (effet indirect). Ce travail a ensuite porté sur le rôle de la qualité globale de l’alimentation, évaluée par le score alimentaire Alternate Healthy Eating Index 2010. Parmi 969 participants d’EGEA, nous avons montré qu’une alimentation de qualité était associée de façon directe à une amélioration des symptômes de l’asthme chez les non-fumeurs. L’effet indirect lié à l’IMC n’était pas significatif. La deuxième partie de la thèse visait à mieux comprendre l'association entre l'obésité et l'activité de l’asthme, en prenant en compte la leptine, une adipokine pro-inflammatoire, comme un médiateur potentiel. Parmi 331 adultes d’EGEA avec un asthme actif à l’inclusion, les analyses ont montré que différentes mesures élevées de la composition corporelle étaient associées à une activité persistante de l’asthme, avec un effet indirect très fort de la leptine dans ces associations. / The general aim of the thesis was to study the role of diet and obesity in asthma, while accounting for potential mediators in these analyses.The first part of the thesis aimed to investigate the role of dietary factors in asthma at a “macro-level”, considering body mass index (BMI) as a potential mediator, and to evaluate effect modification by smoking. We first focused on processed meat intake, a recent carcinogen. Among 971 participants from the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA), analysis showed that high processed meat intake (at least 4 servings/week) was associated with worsening asthma symptoms over time, through a direct effect and to a lesser extent an effect mediated by BMI. We then focused on the overall diet quality assessed by the Alternate Healthy Eating Index 2010. Among 969 participants from the EGEA study, the analyses showed that a greater adherence to a better diet quality was associated with improved asthma symptoms over time in never smokers only and was not mediated through BMI. The second part of the thesis aimed to better understand the association between obesity and asthma at a “micro-level”, considering leptin, an inflammatory biological marker related to obesity, as a mediator. Including 331 participants from the EGEA study with current asthma at baseline, analysis showed that high body adiposity estimated by different measures was associated with persistent asthma activity, likely mediated by leptin.

The main aim of this thesis is to acquire basic knowledge of CAM program hyperMILL 2019 with comparison of the ball nose end mill and circle segment end mill with taper form, economical evaluation and than make force analysis of specimen from aluminium alloy by milling with spindle moulder. Another aim of this thesis is also an analysis of force effects and force directions of the milling tool, advantages by using the circle segment end mill with taper form, the most common types of aluminium alloys and their mechanical properties and next comparison of CAM program hyperMILL with other selected program in the theoretic part.

The presented thesis deals with the monitoring sensory quality of processed cheese analogues, focusing mainly on the taste (flavour) and related content of volatile (aroma active) substances. Model samples of analogues were produced by a standard procedure at Tomas Bata University in Zlín. The experimental part was divided into two experiments, which differed in the composition of model samples of analogues. In the first experiment, the traditional fat (butter) was completely replaced by selected vegetable fats (palm, coconut, mixed), in the second experiment only a part (1% w/w - expressed on the total weight of the sample) of butter was replaced by vegetable oils (apricot, flax seed, currant, grape seed). Solid phase microextraction in conjunction with gas chromatography with flame ionization detection was used to determine volatiles. Methods based on valid international standards were used to evaluate the sensory quality of samples, focusing mainly on flavor, namely evaluation using scales (ISO 4121), profile test (EN ISO 13299) and ranking test (ISO 8587). The aim of the work was to assess the effect of the addition of various vegetable fats/oils on the above parameters, at the same time their changes were monitored during 6 months of storage (at 6 ° C). The results showed that the vegetable oil used affects both the sensory quality and the content and composition of volatile substances of analogues. Significant differences between samples were mainly in taste, aroma and overall acceptability. The decreasing overall acceptability of the samples can be expressed in experiment I by the order: product with butter coconut palm mixed fat; in the case of experiment II: product with butter apricot = flax = grape currant oil. Mixed fat, currant and grape seed oil proved to be unsuitable for the production of analogues, on the contrary, analogues with coconut fat and apricot oil were evaluated best. Based on the results of sensory analyses, it was shown that the samples maintain a good sensory quality min. for 3 months while maintaining a low storage temperature ( 6 ° C). An analogue with coconut fat, whose taste, aroma and acceptability were rated as very good, and apricot oil, whose taste, aroma and acceptability were even rated as excellent, could enrich the food offer on the market.

This study examined the determinants of U.S. foreign direct investment (FDI) and exports of processed food. This study also examined the impact of U.S. FDI on U.S. exports on processed food. FDI and export models used for estimation in this study were based on the cost-minimizing production function. The analysis focused on ten countries for the period of 1989-2004. Four of them were Asian countries: India, Japan, South Korea, and Thailand. Six of them were European countries: Belgium, France, Germany, Italy, Spain, and the United Kingdom. The model was estimated using the two-way error component three-stage least squares (EC3SLS) method. Results from this study show that U.S. FDI and U.S. exports of processed food are complements. Major factors affecting U.S. FDI in the processing industry are GDP, GDP per capita, exchange rate, tariff rate, labor compensation cost, interest rate, and distance. Major factors affecting U.S. exports in the processed food industry are GDP, distance, and GDP from the agri-sector.

Organic field-effect transistors (OFETs) have attracted tremendous attention due to their flexibility, transparency, easy processiblity and low cost of fabrication. High-performance OFETs are required for their potential applications in the organic electronic devices such as flexible display, integrated circuit, and radiofrequency identification tags. One of the major limiting factors in fabricating high-performance OFET is the large interfacial barrier between metal electrodes and OSC which results in low charge injection from the metal electrodes to OSC. In order to overcome the challenge of low charge injection, carbon nanotubes (CNTs) have been suggested as a promising electrode material for organic electronic devices. In this dissertation, we study the effect of carbon nanotube (CNT) density in CNT electrodes on the performance of organic field effect transistor (OFETs). The devices were fabricated by thermal evaporation of pentacene on the Pd/single walled CNT (SWCNT) electrodes where SWCNTs of different density (0-30/um) were aligned on Pd using dielectrophoresis (DEP) and cut via oxygen plasma etching to keep the length of nanotube short compared to the channel length. From the electronic transport measurements of 40 devices, we show that the average saturation mobility of the devices increased from 0.02 for zero SWCNT to 0.06, 0.13 and 0.19 cm2/Vs for low (1-5 /µm), medium (10-15 /µm) and high (25-30 /µm) SWCNT density in the electrodes, respectively. The increase is three, six and nine times for low, medium and high density SWCNTs in the electrode compared to the devices that did not contain any SWCNT. In addition, the current on-off ratio and on-current of the devices are increased up v to 40 times and 20 times with increasing SWCNT density in the electrodes. Our study shows that although a few nanotubes in the electrode can improve the OFET device performance, significant improvement can be achieved by maximizing SWCNT/OSC interfacial area. The improved OFET performance can be explained due to a reduced barrier height of SWCNT/pentacene interface compared to metal/pentacene interface which provides more efficient charge injection pathways with increased SWCNT/pentacene interfacial area.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24903号 / 工博第5183号 / 新制||工||1989(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 梶 弘典, 教授 関 修平, 教授 寺村 謙太郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM