In this study, InSe single crystals were grown from the melt using conventional Bridgman-Stockbarger system. The grown crystals were implanted by N-ions to investigate the doping effect. the stoichiometry and the structural features were examined by scanning electron microscope and X-ray diffraction method, respectively. We have observed that the ingot was stoichiometric and the structure was hexagonal. Temperature dependent conductivity and Hall effect measurements were carried out to investigate the electrical properties of as-grown, as-implanted and annealed samples within the temperature range of 80-400 K. To investigate the annealing effect on both the absorption and photoluminescence (PL) spectra, absorption and PL measurements were performed at room temperature. N-implantation reduced the resistivity order from 103 to 101 (&amp / #937 / -cm). We have used temperature dependent conductivity and Hall effect measurements to analyze the dominant scattering mechanisms. Hall measurements showed that all the samples had n-type conduction. Absorption measurements showed that InSe had direct band gap. It was observed that annealing had almost no effect an both room temperature absorption and PL spectra of the samples.

La seiche commune Sepia officinalis est un Mollusque Céphalopode présent sur les côtes Normandes. En Baie de Seine, elle représente la troisième espèce visée par les flottilles hauturière et côtière, ce qui en fait une ressource économique importante pour la région. Dans un contexte de protection de la ressource, l’étude et la compréhension des mécanismes liés à la reproduction représentent un objectif majeur. Cette étude est donc focalisée sur les mécanismes régulateurs de la ponte, et en particulier sur les facteurs impliqués dans l’émission des ovocytes. Des recherches antérieures effectuées au laboratoire ont mis en évidence un contrôle multifactoriel du processus de ponte, avec trois niveaux de régulation. (i) Les neuropeptides sont impliqués dans la perception des paramètres environnementaux, (ii) les facteurs ovariens assurent la régulation paracrine du tractus génital, et (iii) les phéromones sexuelles, tout en interférant avec la ponte, sont suspectées de jouer un rôle important dans le comportement des géniteurs associé à la reproduction. Cette thèse met en lumière le rôle de 2 familles de neuropeptides identifiées récemment : les CCAPs et les FLGamides (ou So-orcokinines B). Ces deux familles participent au transport de l’ovocyte et à la sécrétion capsulaire en agissant sur l’activité contractile du complexe oviducte/glande de l’oviducte et des glandes nidamentaires principales. Ces neuropeptides sont par ailleurs suspectés de jouer un rôle dans la biosynthèse des protéines vitellines et des protéines capsulaires. Parallèlement, des phéromones sexuelles sont exprimées par la glande de l’oviducte et sécrétées avec les protéines capsulaires. Des travaux antérieurs ont permis de caractériser des produits d’expression issus de clivages de type prohormone convertase. Dans cette nouvelle étude, un second mode de clivage a été mis en évidence avec l’identification de produits de clivage de masse moléculaire supérieure à 20 kDa. L’un de ces produits, la phéromone beta, a été produit en système recombinant mais son activité biologique sur l’appareil génital mâle et sur l’oviducte n’a pas été démontrée. Quant aux tests comportementaux, ils n’ont pu être exploités du fait d’un nombre d’animaux testés trop restreint. Enfin, une approche transcriptomique comparative et différentielle réalisée à partir de l’organe olfactif mâle et du pavillon de l’oviducte a permis d’identifier un récepteur candidat à la liaison avec les phéromones sexuelles / The common cuttlefish (Sepia officinalis) is a Cephalopod mollusk found on the Normandy coasts. In the Bay of Seine, it is the third species targeted by offshore and coastal fleets, so it is an important economic resource for the whole region. In a context of resource protection, the study and understanding of its reproductive mechanisms is a major objective. This study is therefore focused on the regulatory mechanisms of egg-laying, and in particular on the factors involved in the release of oocytes. Previous research in the laboratory demonstrated multifactorial control of the egg-laying process, with three levels of regulation: (i) neuropeptides involved in the perception of environmental cues, (ii) ovarian factors providing paracrine regulation of the genital tract, and (iii) sexual pheromones, which are implied in egg-laying and are suspected to play a determining role in the reproductive behavior. This thesis highlights the role of two families of recently identified neuropeptides called CCAPs and FLGamides (or So-orcokinins B). These two families participate in oocyte transport and in egg capsule secretion by acting on the contractile activity of the oviduct/oviduct gland complex and of the main nidamental glands. These neuropeptides are also suspected to play a role in the biosynthesis of yolk and capsular proteins. At the same time, sex pheromones are expressed by the oviduct gland and secreted along with capsular proteins. Previous work made it possible to characterize expression products resulting from cleavages of the prohormone convertase type. In this new study, a second mode of cleavage is highlighted, evidenced by the identification of cleavage products with MWs greater than 20 kDa. One of these products, beta pheromone, was produced in a recombinant system but its biological activity on the male reproductive system and on the oviduct was not demonstrated. As for behavioral tests, they were not exploited because the number of animals tested was too small. Finally, a comparative and differential transcriptomic approach of the male olfactory organ and the oviduct pavilion evidenced a candidate receptor expected to bind to sex pheromones

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-07T15:15:55Z No. of bitstreams: 1 PGCS15MA156.pdf: 2654919 bytes, checksum: 53e7b0ccf7729ee5d0e5bb39ed4bd14b (MD5) / Made available in DSpace on 2018-03-07T15:15:55Z (GMT). No. of bitstreams: 1 PGCS15MA156.pdf: 2654919 bytes, checksum: 53e7b0ccf7729ee5d0e5bb39ed4bd14b (MD5) Previous issue date: 2015-12-21 / Biological nitrogen fixation involves a series of processes beginning with the adaptation of the bacteria to the plant and terminate in fixation of atmospheric N2, being mediated by a portion of prokaryotes that, though relatively small, exhibits high morphological diversity, physiological, genetic and Phylogenetic. The study aimed to Morphophysiological and genetic characterization of nitrogen fixing bacteria nodulation seven forest legume trees. In all, 79 isolates obtained in winter and summer period, the studied species. Based on the morphological and physiological properties, the isolates were classified into eight groups. For DNA analysis of isolated after amplification with OPA-4 RAPD, there has been a high degree of genetic diversity, obtaining 19 different groups, and for the amplification ERIC gave 18 groups, both with 90% similarity. The populations of rhizobia differ even by PCR-RFLP of the 16S ribosomal gene with the digestion by HinfI restriction endonuclease and were obtained 54 groups with 90% similarity, which could indicate the occurrence of different species within the genus Burkholderia the which prevailed in the study. Although there was a predominance genus Burkholderia, the results indicate that this predominance was due to nutritional and adaptive versatility of its kind, characterizing the high degree of polymorphism and dominance in the study / A fixação biológica do nitrogênio (FBN) envolve uma sucessão de processos que começam com a adaptação da bactéria à planta e culminam na fixação do nitrogênio atmosférico, sendo mediada por uma parcela dos procariotos que, apesar de relativamente pequena, apresenta alta diversidade morfológica, fisiológica, genética e filogenética. O estudo teve por objetivo a caracterização morfofisiológica e genética de bactérias fixadoras de nitrogênio nodulantes de sete leguminosas arbóreas florestais. Ao todo, foram obtidos 79 isolados no período do inverno e verão, nas espécies estudadas. Com base nas propriedades morfofisiológicas, os isolados foram classificados em oito grupos. Pela análise do DNA dos isolados após a amplificação com OPA-4 em RAPD, foi possível constatar um grau elevado de diversidade genética, com a obtenção de 19 grupos distintos e, pela amplificação por ERIC obteve-se 18 grupos, ambas com 90% de similaridade. As populações de rizóbios diferiram ainda pela técnica de PCR-RFLP do gene ribossomal 16S, com a digestão pela endonuclease de restrição HinfI, e foram obtidos 54 grupos com 90% de similaridade, que poderiam indicar a ocorrência de espécies distintas dentro do gênero Burkholderia a qual prevaleceu no estudo. Os resultados indicam que a predominância do gênero Burkholderia ocorreu devido a versatilidade nutricional e adaptativa do gênero, caracterizando assim o elevado grau de polimorfismo e dominância no estudo

Submitted by Ana Paula Santos da Silva (ana.paula1@outlook.com) on 2018-04-13T00:44:19Z No. of bitstreams: 1 Defesa Mestrado- versão final.pdf: 2552832 bytes, checksum: 9589b4e1630518c51f6b72f3850d78d9 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-04-13T17:50:34Z (GMT) No. of bitstreams: 1 silva_aps_me_guara.pdf: 2552832 bytes, checksum: 9589b4e1630518c51f6b72f3850d78d9 (MD5) / Made available in DSpace on 2018-04-13T17:50:34Z (GMT). No. of bitstreams: 1 silva_aps_me_guara.pdf: 2552832 bytes, checksum: 9589b4e1630518c51f6b72f3850d78d9 (MD5) Previous issue date: 2018-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O segmento de painéis à base de madeira tem se destacado no setor madeireiro pelo uso de tecnologia moderna em seus equipamentos e uso mais racional da matéria-prima. No entanto, a busca por produtos melhores e mais competitivos é constante tendo em vista o mercado ser bastante exigente. Sendo assim, definiu-se como objetivo deste estudo a adição de nanopartículas de óxido de zinco (ZnO) na fabricação de painéis de fibras de média densidade e avaliar as influências das mesmas nas propriedades físicas e mecânicas dos painéis produzidos com dois adesivos comerciais e ainda verificar a influência das nanopartículas na transferência de calor durante o processo de prensagem. Os painéis foram produzidos com adição de 0,5% e 1% de nanopartículas com base no peso seco de fibras e painéis testemunha com resina ureia-formaldeído (UF) e melamina-formaldeído (MF) e, os mesmos caracterizados a partir da ABNT NBR 15.316-2:2015. Durante o processo de prensagem através de sistema de aquisição de dados acoplado a um termopar foram obtidas as variações de temperatura do colchão ao longo dos dez minutos do ciclo de prensagem. A partir dos resultados pode-se concluir que o uso das nanopartículas na proporção de 0,5% de nanopartículas não indicou grandes interferências nas propriedades físico-mecânicas dos painéis estudados. A adição de 1% de nanopartículas tanto nos tratamentos com MF e UF interferiu de forma negativa na interação com o adesivo e, assim, reduziu as propriedades físicas e mecânicas dos painéis e, auxiliou a transferência de calor a partir do segundo ciclo de prensagem. / The wood-based panels stood out in the wood segment by the use of modern technology in their equipment and more rational use of the raw material. However, the demand for better and more competitive products is constant, given that the market is quite demanding. Thus, the aim of this study was to add zinc oxide (ZnO) nanoparticles in the production of medium density fiberboards and to evaluate their influence on the physical and mechanical properties of the panels produced with two commercial adhesives and to verify the influence of nanoparticles on the heat transfer during the pressing process. The panels were produced with 0.5% and 1% of nanoparticles based on the dry weight of fibers and control panels with ureaformaldehyde (UF) and melamine-formaldehyde resin (MF) and characterized by ABNT NBR 15.316-2:2015. During the pressing process through a data acquisition system coupled to a thermocouple, the temperature variations of the mattress were obtained during the ten minutes of the pressing cycle. From a preliminary analysis of the results it can be concluded that the use of nanoparticles in the proportion of 0.5% of nanoparticles did not indicate large interferences in the physical-mechanical properties of the panels studied. The addition of 1% of nanoparticles in both MF and UF treatments interfered negatively in the interaction with the adhesive and thus reduced the physical and mechanical properties of the panels and assisted the heat transfer from the second pressing cycle

O policloreto de vinila (PVC) é comercialmente utilizado em diversas aplicações, destacando-se os filmes flexíveis. Para a fabricação destes compostos de PVC, utilizam-se vários tipos de aditivos, tais como plastificantes, estabilizantes térmicos, lubrificantes, retardantes de chama e outros. No presente trabalho foram produzidos compostos de PVC a partir de uma formulação referencial, variando-se a concentração de pigmento, carga, modificador de impacto e plastificantes. A preparação das amostras foi feita através de uma misturadeira intensiva (Mecanoplast), calandra de 2 rolos e prensa, obtendo-se placas flexíveis de 1 mm de espessura. Os resultados das análises térmicas (DMA e TGA) mostraram que o uso e a quantidade de plastificantes foram os principais fatores que influenciaram as propriedades de mudança de fase (Tg) e estabilidade térmica do material. As análises das propriedades mecânicas (resistência à tração e alongamento) mostraram que estas propriedades foram influenciadas pelas proporções de cargas, modificador de impacto e plastificantes na composição. As medidas elétricas (rigidez dielétrica) não foram afetadas pela variação da adição de materiais nas amostras analisadas / Poly(vinyl chloride) (PVC) is commercially used in several applications, especially in flexible films. Aiming the production of products, PVC can be filled with a variety of additives, like plasticizers, thermal stabilizers, lubricants, flame-retardants and others. In this work PVC compounds were produced based on a known formulation, using different weight ratios for pigment, filler, impact modifier and plasticizers. Samples were prepared through intensive mixing using two rolls calendrer followed by a hot press to form films with 1 mm thickness. Thermal analysis results (DMA and TGA) showed that plasticizers are the most important factors that influenced the material properties such as phase behavior (Tg) and thermal stability. Mechanical properties analysis (breaking strength and elongation) were influenced by fillers, impact modifier and plasticizers proportions used in the composition. Electrical properties (dielectric breakdown strength) were not affected by different weight ratios in the analyzed samples

Neste trabalho foi investigado o processo de relaxação em copolímeros metacrilicos funcionalizados com o grupo cromóforo 4-[N-etil-N-(2-hidroxietil)]amino-2\'-cloro-4\'nitro-azobenzeno (MMADRI3). Os copolímeros sintetizados foram caracterizados por espectrofotometria de visível e infravermelho, calorimetria diferencial de varredura, análise termogravimétrica e elipsometria. O triodo de corona foi utilizado para induzir a orientação dos cromóforos dipolares a temperaturas próximas da transição vítrea. Os valores do coeficiente eletroóptico linear r13 de filmes obtidos por derramento de solução podem alcançar 14 pm/V em amostras funcionalizadas com 43%de cromóforo.O efeito piezoelétricoé significativo para amostras contendo 4% de cromóforo sendo a sua origem atribuída à carga espacial. A relaxação orientacional dos cromóforos foi estudada medindo-se o decaimento do coeficiente eletroóptico e a relaxação dielétrica a diferentes temperaturas. O processo de relaxação foi interpretado utilizando a equação de Kohlraush-Williams-Watts (KWW) aplicada aos domínios do tempo e da freqüência. O tempo de relaxação característico &#964 e o parâmetro b da equação de KWW foram obtidos como função da temperatura desde a temperatura ambiente até acima da temperatura de transição vítrea. O parâmetro b à temperatura de transição vítrea aproxima-se de 0,6 valor que é atribuído a forças de curto alcance. As medidas dielétricas revelaram duas bandas de relaxação &#946 e &#945 respectivamente a baixas e a altas temperaturas. A relaxação a está relacionada com a transição vítrea e à desorientação dos cromóforos. A dependência de &#964 foi fundamentada nas equações de Arrhenius e de Vogel-Fulcher-Tarmnann-Hesse (VFTH), respectivamente a baixas e a altas temperaturas. Os parâmetros de VFTH encontram-se próximos dos considerados universais. O comportamento de &#964 em toda a gama de temperaturas, foi explicado pela equação de Adam-Gibbs, usando-se os parâmetros de VFTH. O resfriamento a taxas lentas após o processo de polarização aumenta substancialmente o tempo de relaxação e a sua energia de ativação. Os expoentes m e n do modelo de Dissado-Hill baseado na interação de multicorpos foram obtidos em função da temperatura. Os valores do parâmetro n ficam dentro do esperado pela teoria / The relaxation process of side-chain methacrylate copolymers functionalized with the nonlinear optical azo chromophore 4-[Nethyl-N-(2-hydroxyethyl)]-amino-2\'-chloro-4-nitroazobenzene (MMADR13) was investigated. The copolymers synthesized were characterized by visible and infrared spectrophotometry, differential scanning calorimetry, thermogravimetric analysis and ellipsometry. The corona triode was employed to induce the orientation of the dipolar chromophore at a temperature near the glass transition. The linear eletrooptic coefficient r13 of cast fllms can reach values as high as 14 pm/V in samples with 43% of chromophore contento The piezoeletric effect attributed to space charge was only significant in the lowest chromophore content samples (4%). Electrostriction was shown to affect to some extent the quadratic electrooptic measurements. The chromophore relaxation at different temperatures was investigated by both electrooptic decay and dielectric measurements. The relaxation process was interpreted using the Kohlraush-Williams-Watts (KWW) equation both in the time and frequency domains. From the KWW equation the characteristic relaxation time &#964 and the stretching parameter b were obtained from room temperature to temperatures above the glass transition. Near the glass transition b is ca 0.6 which is characteristic of short range interactions. Dielectric measurements revealed two relaxation bands, &#946 and &#945, at low and high temperatures, respectively. The &#945 relaxation was attributed to the glass transition and to the 10ss of chromophore orientational order. The temperature behavior of &#964 was interpreted by the Arrhenius and Vogel-Fulcher-Tammann-Hesse (VFTH) equations. at low and high temperatures. respectivelly. The VFTH parameters lie close to the so-called universal values. In addition the overall temperature dependence was explained by the Adam-Gibbs equation using the VFTH parameters. Using a small cooling rate after corona poling increases substantially the relaxation time and the activation energy .The power law exponents m and n. from Dissado-Hill manybody interactions model were obtained as a function of temperature. The n values are in the range of expected values for the many-body interactions model

Microplastic is a widespread pollutant in marine and fresh water systems. A major pathway by which microplastics end up in these systems is via storm water. Storm water is generated as precipitation drain off of impenetrable surfaces like paving. Microplastic analysis of storm water make up a good foundation for better understanding what sources and factors contribute to microplastic pollution in marine and fresh water systems. This study puts emphasis on characterization and quantification of microplastics through visual characterization. As visual characterization is a subjective form of analysis, the characterization was performed based on guidelines in order to minimize the risk of identifying false positives. The concentration of microplastic was found to be higher in the current study than in comparison to larger water bodies and storm water streams in less urban areas. Fragments, i.e. irregular shaped particles with the appearance of being broken from a larger piece of litter, were found to be the most abundant type of microplastics, pointing at littering as a major source of microplastics in storm water.

Atomic force microscopy (AFM) is widely used to study material properties and domain heterogeneity of polymers. In both quasi-static force spectroscopy and dynamic AFM, challenging complexities such as the presence of different effective tip-surface forces, surface dynamics, and material viscoelasticity can occur on polymer samples. Many models that attempt to link experimental observables to contact mechanics fail to rigorously account for these complexities. This may lead to inaccurate and unreliable predictions, especially when examining soft polymers. Therefore, having access to rigorous models that can facilitate the understanding of the underlying phenomena during tip-surface interaction, explain the observations, and make reliable and accurate predictions, is of great interest. Among the previously developed models, Attard et al. proposed a novel non-Hertzian-based model that has a versatile ability to systematically incorporate different linear viscoelasticity constitutive models and surface adhesive forces. However, the implementation of Attard’s model into the AFM framework is challenging.<div><br></div><div>In a series of studies, we improve the computational speed and stability of Attard’s viscoelastic contact model and embed it into an AFM framework by proposing algorithms for three AFM operational modes: tapping mode, bimodal, and peak force tapping. For each mode, the results are successfully verified/validated against other reliable AFM codes, FEM simulations, and experiments. The algorithms’ predictions illustrate how viscoelasticity and surface adhesive hysteresis of polymeric samples is reflected in AFM observables. However, since Attard’s model does not lead to a closed-form solution for tip-surface interaction force, using that to quantify the surface mechanical properties based on the AFM observables is not straightforward. Therefore, we utilize the data analytics-based approaches such as linear regression and machine learning algorithms to enable the material viscoelasticity and adhesive parameters estimation based on the provided instrument observables.<br></div><div><br></div><div>The set of results reported in this thesis improves the current knowledge about complex phenomena that occur during tip-surface interactions, especially on soft-viscoelastic-adhesive polymers. The introduced “improved Attard’s model” fulfills the need for a continuum mechanics viscoelasticity contact model that rigorously captures the complexities of such samples. The viscoelasticity contact model and the proposed inverse solution algorithms in this thesis facilitate quantitative measurement and discrimination of the surface adhesive and viscoelastic properties based on the acquired nanoscale AFM maps of polymeric samples.<br></div>

The gram-negative bacteria Edwardsiella ictaluri causes significant economic losses in aquacultured fish. Generally considered host-specific to catfish, there are reports of E. ictaluri outbreaks from other aquacultured species, including ornamental fish raised in the southeastern U.S. Thus, a comprehensive phenotypic and genotypic characterization of E. ictaluri isolates from catfish and ornamental aquaculture was warranted. Morphological, biochemical, and protein profiles of catfish and ornamental derived isolates were mostly similar. Plasmid profiles of wild-type isolates were consistent within groups. Analysis of putative anti-microbial resistant isolates from catfish revealed the presence of multi-drug resistant plasmids. Genomic comparisons indicated marked differences among host groups, including unique T4SSs and phage elements among ornamental fish-derived E. ictaluri isolates. An optimal MLSA scheme consisting of eight reference genes was defined, revealing isolates from catfish and ornamental aquaculture form two discrete phyletic lineages. This study advances our understanding of E. ictaluri affecting two important agricultural commodities in the U.S.

No description available.