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Influ?ncia do alum?nio no comportamento segregacional do ?ndio em ligas tern?rias de Ga1-xInxSbStreicher, Morgana 24 March 2015 (has links)
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Previous issue date: 2015-03-24 / Ternary alloys of III-V semiconductor materials, in particular Ga1-xInxSb, are ideal candidates for substrates because of the possibility to define the lattice constant as a function of concentration of the third element, indium, enabling the adjustment of the lattice parameter in accordance to the subsequent epitaxial layer. Therefore, the mono-crystallinity of the epitaxial layer is favored and the tensions at the interface layer/substrate are reduced, allowing to numerous possibilities and applications. Aluminum (Al) is considered an isoelectric dopant for Ga and In, meaning that it does not change the number of charge carriers, but increases the mobility in GaSb crystals. When Al is added to the Ga1-xInxSb ternary alloy, it can have influence over native defects passivating and/or compensating them. To understand the influence of Al on the distribution of indium (In) in ternary alloys of Ga1-xInxSb, pure and doped Ga0,8In0,2Sb crystals were obtained with approximately 1020 atoms/cm3 of Al using a vertical Bridgman system.Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) were used for the structural and compositional characterization of the crystals. The obtained crystals of Ga0,8In0,2Sb, doped with aluminum or not, exhibited segregation of the third element, however, for Ga0,8In0,2Sb:Al crystals the segregation decreased. The crystals of Ga0,8In0,2Sb:Al presented a good structural homogeneity when compared to the undoped alloy, and they were free from cracks and micro cracks. All of the obtained crystals presented precipitates, twins and grains with different concentrations of In. In the crystals doped with aluminum, single regions were observed in the solidification direction, which can be associated to a more uniform distribution of indium.The small compositional variation observed in the crystals, in radial direction, and measured by PIXE, may be related to the solid-liquid interface?s quasi-equilibrium behavior. The results indicated that aluminum has influenced the indium distribution in the crystals, in the solidification direction, and the electrical properties imply that the aluminum may have contributed to the generation of accepter defects such as GaSb, InSb e AlSb, wherein the number of charge carriers increased in the doped crystals. The possibility of complex defects generation such as (VGaGaSb), (VGaInSb) e (VGaAlSb) cannot be excluded, since the charge mobility in the doped crystals decreased. / Ligas tern?rias de materiais semicondutores III-V, nomeadamente Ga1-xInxSb, s?o candidatas ideais para substratos, pois a possiblidade de se definir a constante de rede em fun??o da concentra??o do terceiro elemento, o ?ndio, possibilita o ajuste do par?metro de rede de acordo com a camada epitaxial subsequente. Desta forma, a monocristalinidade da camada epitaxial ? favorecida e as tens?es na interface camada/substrato s?o diminu?das, introduzindo in?meras possibilidades e aplica??es. O alum?nio (Al) ? considerado um dopante isoel?trico do Ga e do In, isto ?, n?o altera o n?mero de portadores de carga, mas aumenta a mobilidade em lingotes de GaSb. Ao ser adicionando na liga tern?ria Ga1-xInxSb, pode influenciar passivando e/ou compensando os defeitos nativos. Para compreender a influ?ncia do Al na distribui??o do ?ndio (In) em ligas tern?ria de Ga1-xInxSb, foram obtidos lingotes de Gao,8In0,2Sb puros e dopados com aproximadamente 1020 ?tomos/cm3 de Al em um sistema Bridgman vertical.An?lises por microscopia eletr?nica de varredura (MEV), espectroscopia por dispers?o de energia (EDS), difra??o de raios X (XRD), emiss?o de raios X induzida por part?culas (PIXE) e emiss?o de raios gama induzida por part?culas (PIGE) foram utilizadas para a caracteriza??o estrutural e composicional dos lingotes. Os lingotes de Ga0,8In0,2Sb obtidos, dopados ou n?o com alum?nio, apresentaram segrega??o do terceiro elemento, por?m, para os lingotes Ga0,8In0,2Sb:Al a segrega??o foi menor. Os lingotes de Ga0,8In0,2Sb:Al apresentaram uma boa homogeneidade estrutural, livres de fissuras e micro trincas, quando comparados ? liga n?o dopada. Todos os lingotes obtidos apresentam forma??o de precipitados, maclas e gr?os com diferentes concentra??es de In. Nos lingotes dopados com alum?nio foram observadas regi?es com pequena quantidade de gr?os na dire??o da solidifica??o, que podem ser atribu?das a uma distribui??o do ?ndio mais uniforme. A pequena varia??o composicional observada nos lingotes, no sentido radial, mensurada por PIXE, pode ser atribu?da ao comportamento pr?ximo ao equil?brio da interface s?lido-liquido.Os resultados obtidos sugerem a influ?ncia do alum?nio na distribui??o de ?ndio nos lingotes, na dire??o da solidifica??o, ao mesmo tempo que as propriedades el?tricas sugerem que o alum?nio possa ter contribu?do para a gera??o de defeitos aceitadores como GaSb, InSb e AlSb, sendo que o n?mero de portadores de carga aumentou nos lingotes dopados. N?o se exclui a possibilidade da gera??o de defeitos complexos como (VGaGaSb), (VGaInSb) e (VGaAlSb), uma vez que a mobilidade das cargas nos lingotes dopados diminuiu.
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Avalia??o in vitro de matrizes de PLGA com horm?nio do crescimento recombinante humano : an?lise estrutural e din?mica de libera??o do horm?nioOliveira, Henrique do Couto de 31 March 2015 (has links)
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Previous issue date: 2015-03-31 / Growth factors such as the recombinant human growth hormone are drawing attention on the field of bone reconstruction. However, due to the protein?s short half-life, biodegradable polymers, like PLGA, have been applied seeking a slower and controlled drug release for topical applications.
Objective: To asses, in vitro, the behavior of PLGA matrices with 2 different rhGH concentrations.
Materials and Methods: Three groups of triplicate samples were created: group I with pure PLGA (control), group II with PLGA loaded with a higher rhGH concentration and group III with PLGA loaded with a lower concentration of the hormone. Each group was analyzed macro and microscopically (SEM) and, by means of the hidrolitic degradation test, the dynamics of release of rhGH as well as the alterations on the pH of the incubation medium were evaluated, throughout 29 days.
Results: Matrices from all groups showed indistinguishable macro and microscopic features. Group II released a higher quantity of rhGH, as expected, however there was no clear release pattern on both groups. rhGH release was observed until the 22? day and there was no statistically significant difference on weight loss between the 3 groups. pH values found were clinically viable.
Conclusion: Morphological properties of the matrices must be assessed according to its applications and target-tissue to be substituted/regenerated and it was not possible to determine a pattern of rhGH distribution within PLGA matrices on this survey. The matrices can be used as rhGH carriers and were able to extend hormone release for a period of 22 days. Wheight loss showed equal patterns (statistically), despite the addition of rhGH to the polymer. The pH values were clinically viable and the reduction of rhGH concentrations on future researches should not be carried out using this methodology, possibly owing to limitations on screening with ultra-violet spectroscopy. / Fatores de crescimento como o horm?nio do crescimento humano recombinante v?m ganhando aten??o no campo da reconstru??o ?ssea. No entanto, devido ? sua meia-vida curta, pol?meros biodegrad?veis, como o PLGA, v?m sendo utilizados visando libera??o mais lenta e controlada deste horm?nio quando de sua aplica??o t?pica.
Objetivo: Avaliar, in vitro, o comportamento de matrizes de PLGA com 2 concentra??es diferentes de rhGH.
Materiais e M?todos: Tr?s grupos de amostras em triplicatas foram montados: grupo I com PLGA puro (controle); grupo II com PLGA associado ao rhGH em maior concentra??o e; grupo III com PLGA associado ao rhGH em menor concentra??o. Cada grupo foi analisado macroscopicamente e microscopicamente (MEV) e, por meio de teste de degrada??o hidrol?tica, avaliou-se a din?mica de libera??o do rhGH assim como as altera??es de pH no meio de incuba??o ao longo de 29 dias.
Resultados: As matrizes dos 3 grupos de estudo ficaram com caracter?sticas morfol?gicas indistingu?veis macro e microscopicamente. O grupo II liberou maior quantidade de rhGH que o grupo III, como era o esperado, no entanto, n?o houve um padr?o claro de libera??o em ambos os grupos. A libera??o de rhGH foi observada at? o 22? dia de avalia??o e n?o houve diferen?a estat?stica na perda de massas entre os grupos. Os valores de pH encontrados foram compat?veis com a aplica??o cl?nica.
Conclus?o: As propriedades morfol?gicas devem ser avaliadas conforme a aplica??o do material e do tecido alvo a ser regenerado/substitu?do e n?o foi poss?vel estabelecer um padr?o de distribui??o do rhGH nas matrizes de PLGA neste estudo. As matrizes podem ser utilizadas como carreadoras de rhGH tendo sido capazes de prolongar a libera??o do horm?nio por um per?odo de 22 dias. A perda de massas se manteve igual (estatisticamente), a despeito da adi??o do rhGH ao pol?mero. O pH das amostras se mostrou favor?vel ? aplica??o cl?nica das matrizes e a redu??o nas concentra??es de rhGH para estudos futuros n?o deve ser avaliada por esta metodologia, visto que podem se tornar de dif?cil leitura pelo EAU-Vis.
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An?lise do efeito do spray de nitrog?nio l?quido em culturas de bact?rias enterococcus faecalis : estudos in vitroBatista, Paulo S?rgio 31 March 2006 (has links)
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Previous issue date: 2006-03-31 / A crioterapia com nitrog?nio l?quido tem sido utilizada em diversas ?reas, inclusive com finalidades terap?uticas. Na Microbiologia, ? vasto o n?mero de pesquisas que abordam o efeito controlador do frio em bact?rias (criobiologia), principalmente com a inten??o de evitar sua prolifera??o. No entanto, pouco se sabe a respeito do efeito da queda brusca e intensa da temperatura, como aquela provocada pelo nitrog?nio l?quido, na forma de spray, em microrganismos como as bact?rias Enterococcus faecalis, freq?entemente encontradas em canais com polpas necrosadas, infec??es pulpares e periapicais refrat?rias ao tratamento endod?ntico. Dessa forma, o objetivo deste trabalho foi analisar, in vitro, o efeito do spray de nitrog?nio l?quido nessas bact?rias cultivadas em laborat?rio, em meios de cultura l?quido (caldo BHI) e s?lido (?gar-BHI). Para isso, uma suspens?o de soro fisiol?gico concentrada ...
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Estudo de rotas de síntese e processamento cerâmico do compósito NiO-YSZ para aplicação como anodo em células a combustível do tipo óxido sólido / Study of synthesis routes and processing of NiO-YSZ ceramic composite for use as anode in solid oxide fuel cell (SOFC)Yoshito, Walter Kenji 17 March 2011 (has links)
Este estudo visa a definição de condições de síntese e processamento cerâmico que possibilitem a obtenção do componente anódico com características adequadas para a operação de uma SOFC (Solid Oxide Fuel Cell), ou seja, boa distribuição microestrutural do NiO na matriz de YSZ e porosidade cerca de 30% após redução de NiO. As rotas de síntese selecionadas englobaram a coprecipitação em meio amoniacal, mistura mecânica dos pós e combustão a partir de sais de nitrato. As técnicas de caracterização de pós empregadas incluíram a difração de raios X, microscopia eletrônica de varredura, microscopia eletrônica de transmissão, difração a laser, adsorção gasosa (BET) e picnometria de hélio. Os resultados obtidos indicaram que empregando-se a técnica de coprecipitação, a perda de Ni2+, na forma de complexo [Ni(NH3)n]2+, pode ser minimizada pelo controle do pH em 9,3, mantendo-se a concentração de Ni2+ na solução inicial em 0,1M. No método de mistura mecânica a melhor condição de dispersão dos pós, sem a sedimentação diferencial, foi obtida para valores de potencial zeta em pH 8,0, fixando-se a concentração de dispersante em 0,8% em massa. Na síntese por combustão observou-se que para composições pobres em combustível, os produtos finais apresentaram-se amorfos e com alta área superficial (120,2 m2.g-1). Para as composições ricas em combustível, uréia, os pós obtidos apresentaram-se cristalinos sendo que a intensidade das reflexões do padrão de DRX aumenta com o aumento do excesso de combustível, devido ao aumento da temperatura de reação. No estudo de sinterabilidade dos compactados preparados a partir de pós preparados pelos três métodos determinou-se a temperatura ao redor de 1300 ºC para máxima taxa de densificação e porosidade entre 6,0 e 14%. Os resultados da redução em atmosfera de H2 dos compósitos confirmam que a cinética de reação ocorre em duas etapas, sendo que a primeira etapa com comportamento linear é controlada por reação química na superfície. Na segunda etapa a redução passa a ser controlada pela difusão do gás nos micros poros, gerados pela redução do NiO, diminuindo a taxa de redução. / This study aim the definition of synthesis and ceramic processing conditions of the anodic component suitable for operation of SOFC, i.e, homogeneous distribution of NiO in YSZ matrix and porosity after reduction above 30%. The selected synthesis routes included the co-precipitation in ammonia media, mechanical mixing of powders and combustion reaction from nitrate salts. The characterization techniques of powders included the X-ray diffraction, scanning and transmission electron microscopy, laser diffraction, nitrogen gas adsorption technique (BET) and Helium pycnometry. The obtained results indicated that the loss of Ni2+ in co-precipitation process, due to the formation of complex [Ni(NH3)n]2+, can be minimized by controlling the pH around 9.3, keeping the concentration of nickel cation in the solution to be precipitated around 0.1M. In the mechanical mixing method the best condition of powder dispersion, without differential sedimentation, was obtained for zeta potential values at pH around 8.0, fixing the dispersant concentration at 0.8%. For the combustion synthesis it was observed that when stoichiometric and twofold stoichiometric urea was used, amorphous phase was formed and a higher surface area was attained in the final products. Employing the fuel-rich solution condition, crystallization of the powder was observed and the relative intensity of reflections of XRD patterns increased with excess of fuel, due to increasing the reaction temperature. Sinterability studies of pellets prepared from powder synthesized by the three routes described above showed the temperature around 1300 º C for maximum rate densification and porosity between 6.0 and 14%. Reduction results of the composites confirmed that the reduction kinetics occurs in two steps. The first one with a linear behavior and controlled by chemical reaction on the surface. The second reduction step is the reduction that is controlled by gas diffusion in micro pores, generated by reduction of nickel oxide, decreasing the rate of reduction.
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Caracteriza??o fisiol?gica da resposta a aduba??o nitrogenada em duas cultivares de arrozZONTA, Everaldo 11 July 1996 (has links)
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Previous issue date: 1996-07-11 / CNPq / An experiment was carried out to study the seasonal pattern of dry mass and nitrogen (N) distribution in the vegetative and reproductive parts of two rice cultivars of contrasting aerial architecture, as a function of the application of N in the maximum tillering stage. Substrate from the Ap horizon of a Red Yellow Podzolic soil was used as substrate. The cultivars Comum Branco (dryland) and IAC 4440 (irrigated) were combined with five application levels of N (as Ammonium Sulfate): 0, 2, 4, 6 and 8 g N m-2 in the maximum tillering, and grown in pots arranged in a completely randomized, greenhouse. During the plant cycle, seven successive collections were carried out in order to follow the phasic development as days after planting (DAP): beginning of tillering, maximum tillering, panicle differentiation, stem elongation, flowering, milky / pasty grain and physiological maturation of the grain, which corresponded to collections at 20, 40, 60, 80, 100, 115 and 135 DAP respectively. In each collection were determined the dry mass of: green and senescent leaves, stems and sheaths and roots. The green leaf area and root area were also determined. The N contents were determined in all these fractions by micro Kjeldhal technique. In the final collection the components of the production were evaluated: mass and number of panicle, viable and sterile grain, and their corresponding N contents. The experimental data were combined for the purpose of analysis of variance, in the form of a cultivar factorial x dose x DAP . Primary functions were adjusted from the data of dry mass and total N, foliar and root area, from which the growth and accumulation rates were derived, to obtain net assimilation rates and N influx rates. it was observed that during the period prior to flowering there were no differences in accumulation of total dry matter between the cultivars. There was a higher dry mass allocated in stalks and sheaths, and lower weight of senescent leaves mass in IAC 4440. The partition of dry mass in favor of roots was similar in both cultivars. The cultivar IAC 4440 established a potential productive superiority due to its greater number of tillers. As a consequence, it maintained a longer duration of photosynthetically active leaf area, resulting in a higher daily accumulation rate of dry matter and leaf area. Regarding the N accumulation patterns in the different biomass fractions, the same trend as that observed for dry mass accumulation was observed. However, the maximum rate of maximum accumulation of N occurred in both cultivars, rather than the maximum dry matter accumulation. Leaf N contents in both cultivars were similar until flowering. IAC 4440 had greater specific leaf area in the period, suggesting greater leaf N dilution. When compared to leaf area equality, the net assimilation rate was higher in IAC 4440, which indicates that the overproduction of area, affected the photosynthetic potential in this cultivar, to a greater degree than in Common White. In the post-flowering period, the dry matter partitioning pattern, which was rigidly fixed in pre-flowering, was manifested in a sustained remobilization of photoassimilates and N to the panicle in IAC 4440, evidenced by the reduction of dry mass and N contents of stalks and sheaths during the first 15 days post-flowering and additional contribution of N and C from marked leaf senescence in the maturation period. There was detention of the photo-assimilates and N remobilization of the panicle in Common White, after 15 days post-flowering, with consequent accumulation of dry matter and N in leaf stems and sheaths. The development of a secondary drainage originated in post-flowering neo-tillering may have subtracted photosynthates, otherwise able to be applied in the filling of the growing panicle. A higher grain weight per plant in IAC 4440 was explained by a higher number of panicles and a higher number of viable seeds, and lower crude protein levels, compared to White Common. Regarding the dry mass and nitrogen distribution patterns during the cycle of the cultivars, the effects resulting from the single application of N at the maximum tillering were diluted during the development of the plants, so that they had very little effect on the dynamics of retranslocation of C and N after flowering. This dilution effect was responsible for the non-significance of the interaction of practically none of the primary descriptive growth parameters of the cultivars. No effect of N on phasic development was also noted. The higher levels of N applied favored an increase in net assimilation due to an increase in leaf N content. At higher levels of N application, leaf mass increased without area promotion, which was evidenced by the increase in its specific weight. However, the N content did not significantly reduce leaf senescence; The application of N did not affect significantly the production, only affecting an increase in the percentage of sterility of the spikelets, which counterbalanced the gain of one panicle per plant. As a global result of the work, it was concluded that the patterns of dry matter production and C and N remobilization to the grain, are regulated genetically, showing cultivar specificity. Therefore, nitrogen fertilization is efficient only in order to ensure high rates of physiological activity of panicles and other organs related to grain filling, but not in changing the pattern itself. / Foi instalado um experimento com o objetivo de estudar o padr?o sazonal de distribui??o de massa seca e nitrog?nio (N) nas partes vegetativas e reprodutivas de duas cultivares de arroz de arquitetura a?rea contrastante, em fun??o da aplica??o de N no est?gio de m?ximo perfilhamento. Usou-se como substrato terra proveniente do horizonte Ap de um solo Podz?lico Vermelho Amarelo. As cultivares Comum Branco (de sequeiro) e IAC 4440 (irrigada) foram combinadas com cinco n?veis de aplica??o de N (na forma de Sulfato de Am?nia): 0, 2, 4, 6 e 8 g N m-2, no est?gio de m?ximo perfilhamento, e cultivadas em potes dispostos de forma inteiramente casualizada, em casa de vegeta??o. Durante o ciclo das plantas foram realizadas sete coletas sucessivas, de forma a acompanhar o desenvolvimento f?sico como dias ap?s plantio (DAP): in?cio do perfilhamento, perfilhamento m?ximo, diferencia??o da pan?cula, elonga??o de colmos, flora??o, gr?o leitoso/pastoso e matura??o fisiol?gica do gr?o, o que correspondeu ? coletas aos 20, 40, 60, 80, 100, 115 e 135 DAP respectivamente. Em cada coletas foram determinados a massa seca de: folhas verdes e senescentes, colmos e bainhas e ra?zes. A ?rea foliar verde e ?rea radicular foram tamb?m determinadas. Os teores de N foram determinados em todas estas fra??es, por t?cnica de micro Kjeldhal. Na coleta final foram avaliados os componentes da produ??o: massa e n?mero de pan?cula, gr?o vi?vel e est?ril, e seus correspondentes teores de N. Os dados experimentais foram combinados para finalidade de an?lise de vari?ncia, na forma de um fatorial cultivar x dose x DAP. Fun??es prim?rias foram ajustadas a partir dos dados de massa seca e conte?do total de N, ?rea foliar e radicular, das quais foram derivadas as taxas de crescimento e de ac?mulo, para f?ns de obten??o das taxas de assimila??o l?quida e influxos de N. Concluiu-se que durante o per?odo anterior ? flora??o, n?o existiram diferen?as em ac?mulo de mat?ria seca total entre as cultivares. Houve maior massa seca alocada em colmos e bainhas, e menor peso de massa de folhas senescentes em IAC 4440. A parti??o de massa seca em favor de ra?zes resultou similar em ambas as cultivares. A cultivar IAC 4440 estabeleceu uma superioridade produtiva potencial em fun??o de seu maior n?mero de perfilhos. Como consequ?ncia, manteve maior dura??o de ?rea foliar fotossinteticamente ativa, resultando em maior taxa de ac?mulo di?rio de mat?ria seca e ?rea foliar. Com rela??o aos padr?es de ac?mulo de N nas diferentes fra??es da biomassa, foi observado a mesma tend?ncia que a verificada para ac?mulo de massa seca. Por?m, a taxa m?xima de m?ximo ac?mulo de N, aconteceu em ambas as cultivar, antes do que os m?ximos de ac?mulo de mat?ria seca. Os teores de N foliares em ambas as cultivares foram similares at? a flora??o. IAC 4440 teve maior ?rea foliar espec?fica no per?odo, sugerindo maior dilui??o de N foliar. Quando comparadas ? igualdade de ?rea foliar, a taxa de assimila??o l?quida foi superior em IAC 4440, o que indica que a sobreprodu??o de ?rea, prejudicou o potencial fotossint?tico nesta cultivar, em maior grau que em Comum Branco. No per?odo p?s-flora??o, o padr?o de parti??o de mat?ria seca ao gr?o, o qual foi rigidamente fixado na pr?-flora??o, manifestou-se em uma remobiliza??o sustentada de fotoassimilados e N ? pan?cula em IAC 4440, evidenciado pela redu??o de massa seca e conte?do de N de colmos e bainhas durante os primeiros 15 dias p?s-flora??o e contribui??o adicional de N e C a partir de acentuada senesc?ncia foliar no per?odo de matura??o. Houve deten??o da remobiliza??o de fotoassimilados e de N ? pan?cula em Comum Branco, ap?s os 15 dias p?s-flora??o, com consequente ac?mulo de mat?ria seca e N em colmos e bainhas foliares. O desenvolvimento de um dreno secund?rio originado em neo-perfilhamento p?s-flora??o, pode ter subtra?do fotossintatos, de outra forma, pass?veis de serem aplicados no enchimento da pan?cula em crescimento. Um maior peso de gr?os por planta em IAC 4440 foi explicado por maior n?mero de pan?culas e maior n?mero de sementes vi?veis, e menores teores de prote?na bruta, em rela??o a Comum Branco. Com rela??o aos padr?es de distribui??o de massa seca e nitrog?nio durante o ciclo das cultivares, os efeitos decorrentes da aplica??o ?nica de N por ocasi?o do m?ximo perfilhamento foram dilu?dos durante o de desenvolvimento das plantas, de forma que tiveram efeito muito reduzido sobre a din?mica de retransloca??o de C e N p?s-flora??o. Esse efeito de dilui??o foi respons?vel pela n?o significa??o da intera??o de praticamente nenhum dos par?metros prim?rios descritivos de crescimento das cultivares. Tamb?m n?o foi notado efeito do N no desenvolvimento f?sico. Os maiores n?veis de N aplicados, favoreceram um aumento da assimila??o l?quida devido ? um aumento no teor de N foliar. Aos maiores n?veis de aplica??o de N, o peso de massa foliar aumentou, sem promo??o de ?rea, o que foi evidenciado pelo aumento do seu peso espec?fico. Entretanto, o teor de N n?o reduziu significativamente a senesc?ncia foliar; A aplica??o de N n?o afetou significativamente a produ??o, incidindo apenas num aumento da percentagem de esterilidade das espiguetas, que contrabalanceou o ganho de uma pan?cula por planta. Como resultado global do trabalho, foi concluido que os padr?es de produ??o de mat?ria seca e de remobiliza??o de C e N ao gr?o, est?o regulados geneticamente, mostrando especificidade de cultivar. Portanto, a fertiliza??o nitrogenada ? eficiente apenas no sentido de assegurar altas taxas de atividade fisiol?gica das pan?culas e demais ?rg?os relacionados ao enchimento de gr?os, mas n?o na mudan?a do padr?o em s?.
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Smart på olika sätt : Jämförande studie hur två skolor arbetar efter Howard Gardners lärteoriErmén Luterkort, Mikaela, Monfors, Mikaela January 2011 (has links)
Syftet med denna studie är att undersöka om och i sådant fall hur fyra lärare använder sig av Gardners lärteori i undervisningen på två skolor. Skolan A är en profilskola som enligt hemsidan och rektorn medvetet arbetar efter psykologen Howard Gardners teorier om de nio intelligenserna, det vill säga olika typer av kognitiva förmågor. Skola B arbetar inte aktivt efter Gardners teorier. I studien undersöks hur undervisning och klassrumsmiljö anpassats till de nio förmågorna under fyra matematiklektioner. För att få svar på studiens frågeställningar användes intervjuer och observationer. Studiens huvudresultat blev att skola A inte arbetade efter Howard Gardners teorier vilket ledde till att resultatet istället baseras på två skolor med likvärdig profil. Utifrån detta kom studien fram till att både antalet och vilka intelligenser som fanns representerade i lektionernas innehåll och klassrummens uppbyggnad var i stort sett desamma.
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A Study of the low-energy interfaces between different planes of NiOLee, Chung-Lin 26 July 2011 (has links)
A nanofilm rotation method is developed to study the rotation of nanograins and the formation of various low energy interfaces. Epitaxial (100), (110), (111) and (112) NiO nanofilms are prepared by ion beam sputtering onto the (100), (110), (111) and (112) surfaces of NaCl single crystal. By overlapping of the above films with an angle difference, and annealing at relatively low temperatures 100 ¢Jthe nanograins are induced to rotate till a metastable interface is reached. The rotation
process and the metastable interfaces are determined by transmission electron microscopy. Many new interfaces between mixed planes are found, and their orientation relationships and structures are analyzed. The study discovered eight groups of metastable orientation relations, respectively, which have not been reported in literatures.
2¡¦ orientation relationship is [11 ]( 10)//[01 ]( 11)
2¡¦¡¦ orientation relationship is [00 ]( 10)//[ 0 ]( 11)
4e1 orientation relationship is [13 ]( 12)//[110](00 1)
4¡¦ orientation relationship is [1 1]( 12)//[0 0](00 1)
4e2 orientation relationship is [13 ]( 12)//[100](00 1)
5¡¦ orientation relationship is [ 1 ]( 12)// [01 ] ( 11)
6¡¨ orientation relationship is [110]( 12)// [001] ( 10)
6¡¦¡¦¡¦ orientation relationship is [110]( 12)// [ 1] ( 10)
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A study of the ZrO2/NiO interfacesChen, Jiun-Yang 24 August 2011 (has links)
The stable interfaces between NiO and ZrO2 reached by nanofilms interface rotation method are reported in this study. Epitaxial nanofilms of NiO and ZrO2 were synthesized on single crystal NaCl (001), (011), (111) surfaces. All nanofilms are investigated by transmission electron microscopy and selected-area diffraction (SAD) patterns. Composite nanofilms were formed by overlapping nanofilms of NiO and ZrO2 at difference angles and thermally treated. The rotation process and final stable interfaces in the overlapped nanofilms are analyzed by SAD patterns. Orientation relationships and interface rotation are analyzed. This study found five new interfaces.
(1) (001)N/ Z¡A[110]N//[110]Z
(2) (001)N/ Z¡A[100]N//[110]Z
(3) N/ Z¡A[110]N//[110]Z
(4) N/ Z¡A[111]N//[110]Z
(5) N/ Z¡A[001]N//[110]Z
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Elevers syn på undervisningen i ämnet idrott och hälsa : En studie om elever med låg närvaro i ämnetLundberg, Martin January 2012 (has links)
No description available.
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Uso de probi?tico sobre a energia e digestibilidade de nutrientes em ra??es para su?nos / Use of probiotic on energy and nutrient digestibility in diets for pigsSouza, Gabrielle Silva 19 September 2014 (has links)
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Previous issue date: 2014 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Chr. Hansen / Para avaliar os efeitos do uso de probi?ticos sobre a metabolizabilidade da energia e digestibilidade de nutrientes em ra??es para su?nos, realizou-se um experimento com 32 su?nos, machos castrados, com peso de 31,2?4,7Kg, distribu?dos em delineamento experimental em blocos casualizados, em arranjo fatorial 2x2, sendo dois n?veis de energia metaboliz?vel (3200 e 3300 kcal/kg de energia metaboliz?vel), com ou sem adi??o de probi?tico, em 4 tratamentos e 8 repeti??es com um animal por unidade experimental. Os tratamentos foram assim constitu?dos: T1 - ra??o com 3200 kcal/kg de EM (3200 EM), T2 -ra??o T1 + 400 g/tonelada de probi?tico (3200 EM+P), T3 - ra??o com 3300 kcal/kg de EM (3300 EM) e T4 - ra??o T3 + 400 g/tonelada de probi?tico (3300 EM+P) e o per?odo experimental foram de 10 dias, sendo 5 dias para adapta??o dos su?nos ?s gaiolas e 5 dias para coleta de fezes e urina. Foram determinados os valores digest?veis da energia (ED), energia metaboliz?vel (EM), energia metaboliz?vel corrigida para balan?o de nitrog?nio (EMn), prote?na bruta (PB), extrato et?reo (EED), fibra bruta (FD), fibra em detergente neutro (FDND) e fibra em detergente ?cido (FDAD), mat?ria mineral (MMD), c?lcio (CaD) e f?sforo (PPD) das ra??es, para c?lculo dos coeficientes de metabolizabilidade e digestibilidade da energia e dos nutrientes. Maiores valores (P<0,05) de ED, EM e EMn, FDAD, EED e coeficiente de digestibilidade de extrato et?reo foram determinados na ra??o contendo 3300 EM+P. N?o houve diferen?a (P>0,05) entre as ra??es em rela??o aos coeficientes de digestibilidade e metabolizabilidade de energia, assim como para os valores de MMD, CaD, PPD, PD, FD e FDND. A inclus?o de probi?tico nas ra??es proporcionou incremento na energia das ra??es, devido ? melhoria na digestibilidade da FDA e EE. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / ABSTRACT
To evaluate the effects of probiotics on the metabolizable energy and digestibility of nutrients in diets for pigs, we made an experiment with 32 pigs, barrows weighing 31.2 ? 4,7Kg distributed in experimental design randomized blocks in a 2x2 factorial arrangement, with two levels of metabolizable energy (3200 and 3300 kcal / kg metabolizable energy), with or without added probiotic in 4 treatments and 8 repetitions with an animal per experimental unit. Treatments were: T1 - diet with 3200 kcal / kg of ME (3200 ME), T2 - T1 diet + 400 g / ton probiotic (3200 ME + P), T3 - diet with 3300 kcal / kg of ME (3300 ME) and T4 - T3 diet + 400 g / ton probiotic (3300 ME + P) and the experimental period was 10 days, with 5 days for adaptation of pigs cages and 5 days for collection of faeces and urine. We evaluated the digestible of energy (DE), metabolizable energy (ME), metabolizable energy corrected for nitrogen (MEn), crude protein (CP), ether extract (EE), crude fiber (FD), neutral detergent fiber (DNDF) and acid detergent fiber (DADF), mineral matter (MMD), calcium (CaD) and phosphorus (PPD) to calculate the coefficients of digestibility and metabolizable energy and nutrients. Higher values were found ??(P <0.05) of ED, ME, MEn, DADF, EE and digestibility of ether extract in diets containing 3300 ME + P. There was no difference (P> 0.05) among diets in relation to digestibility and metabolizable energy, as well as the values ??of PD, FD, DNDF, MMD, CaD and PPD. The inclusion of probiotics in feed resulted in increased energy rations due to improved digestibility of DADF and EE.
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