965 resultados para Micro-structures
Resumo:
Many studies on the morphology, molecular orientation, device performance, substrate nature and growth parameter dependence have been carried out since the proposal of Sexithiophene (6T) for organic electronics [ ] However, these studies were mostly performed on films thicker than 20nm and without specifically addressing the relationship between morphology and molecular orientation within the nano and micro structures of ultrathin films of 0-3 monolayers. In 2004, the observation that in OFETs only the first few monolayers at the interface in contact with the gate insulator contribute to the charge transport [ ], underlined the importance to study submonolayer films and their evolution up to a few monolayers of thickness with appropriate experimental techniques. We present here a detailed Non-contact Atomic Force Microscopy and Scanning Tunneling Microscopy study on various substrates aiming at the investigation of growth mechanisms. Most reported similar studies are performed on ideal metals in UHV. However it is important to investigate the details of organic film growth on less ideal and even technological surfaces and device testpatterns. The present work addresses the growth of ultra thin organic films in-situ and quasi real-time by NC-AFM. An organic effusion cell is installed to evaporate the organic material directly onto the SPM sample scanning stage.
Resumo:
A presente tese tem como objetivo abordar e analisar a violência contra a mulher e a relação que existiria entre essa conduta e a imagem androcêntrica de "Deus", em um contexto específico: homens e mulheres da Igreja Metodista no Chile. Fizemos uma leitura analítica da maneira de se relacionar as mulheres e os homens nos matrimônios, e as mulheres e os homens com "Deus". O intuito é explorar as similitudes que existem entre a atitude hierárquica do homem na sociedade e na família e o modelo de "Deus" masculino presente no imaginário coletivo da sociedade. A questão foi desenvolvida tendo como eixo principal a imagem indrocêntrica de "Deus" e as variáveis que desde essa imagem se desprendem, a saber, a construção e a ideologia androcêntrica, a sobrevalorização da hegemonia e a linguagem masculina e a legitimação da violência contra mulher. Esta situação é analisada desde um contexto específico a Igreja Metodista no Chile, mas este fato é apenas o contexto de onde começamos a observar os casos de violência contra a mulher, o que permitiu sair desse contexto restringido, para um contexto mais abrangente. Por conseguinte, na procura de fundamentos para elucidar as hipóteses, levantamos alguns elementos antropológicos herdados das ideologias e crenças dos espanhóis e dos indígenas, os quais foram fundamentais na construção do ethos e da idiossincrasia chilena. Para a análise e a crítica do imaginário masculino de Deus, privilegiamos a produção da teologia feminista e, para o conceito de violência que contem a noção de poder, privilegiamos a concepção de micro-poder, estimando que a violência contra da mulher se concretiza, primordialmente, em nível de micro estruturas, ainda que o fato esteja legitimado em nível de macro estruturas. O objetivo desta tese é contribuir na reflexão teológico-pastoral desde a perspectiva da mulher, visando fornecer elementos de debate no caminho à superação da violência.(AU)
Resumo:
A presente tese tem como objetivo abordar e analisar a violência contra a mulher e a relação que existiria entre essa conduta e a imagem androcêntrica de "Deus", em um contexto específico: homens e mulheres da Igreja Metodista no Chile. Fizemos uma leitura analítica da maneira de se relacionar as mulheres e os homens nos matrimônios, e as mulheres e os homens com "Deus". O intuito é explorar as similitudes que existem entre a atitude hierárquica do homem na sociedade e na família e o modelo de "Deus" masculino presente no imaginário coletivo da sociedade. A questão foi desenvolvida tendo como eixo principal a imagem indrocêntrica de "Deus" e as variáveis que desde essa imagem se desprendem, a saber, a construção e a ideologia androcêntrica, a sobrevalorização da hegemonia e a linguagem masculina e a legitimação da violência contra mulher. Esta situação é analisada desde um contexto específico a Igreja Metodista no Chile, mas este fato é apenas o contexto de onde começamos a observar os casos de violência contra a mulher, o que permitiu sair desse contexto restringido, para um contexto mais abrangente. Por conseguinte, na procura de fundamentos para elucidar as hipóteses, levantamos alguns elementos antropológicos herdados das ideologias e crenças dos espanhóis e dos indígenas, os quais foram fundamentais na construção do ethos e da idiossincrasia chilena. Para a análise e a crítica do imaginário masculino de Deus, privilegiamos a produção da teologia feminista e, para o conceito de violência que contem a noção de poder, privilegiamos a concepção de micro-poder, estimando que a violência contra da mulher se concretiza, primordialmente, em nível de micro estruturas, ainda que o fato esteja legitimado em nível de macro estruturas. O objetivo desta tese é contribuir na reflexão teológico-pastoral desde a perspectiva da mulher, visando fornecer elementos de debate no caminho à superação da violência.(AU)
Resumo:
A presente tese tem como objetivo abordar e analisar a violência contra a mulher e a relação que existiria entre essa conduta e a imagem androcêntrica de "Deus", em um contexto específico: homens e mulheres da Igreja Metodista no Chile. Fizemos uma leitura analítica da maneira de se relacionar as mulheres e os homens nos matrimônios, e as mulheres e os homens com "Deus". O intuito é explorar as similitudes que existem entre a atitude hierárquica do homem na sociedade e na família e o modelo de "Deus" masculino presente no imaginário coletivo da sociedade. A questão foi desenvolvida tendo como eixo principal a imagem indrocêntrica de "Deus" e as variáveis que desde essa imagem se desprendem, a saber, a construção e a ideologia androcêntrica, a sobrevalorização da hegemonia e a linguagem masculina e a legitimação da violência contra mulher. Esta situação é analisada desde um contexto específico a Igreja Metodista no Chile, mas este fato é apenas o contexto de onde começamos a observar os casos de violência contra a mulher, o que permitiu sair desse contexto restringido, para um contexto mais abrangente. Por conseguinte, na procura de fundamentos para elucidar as hipóteses, levantamos alguns elementos antropológicos herdados das ideologias e crenças dos espanhóis e dos indígenas, os quais foram fundamentais na construção do ethos e da idiossincrasia chilena. Para a análise e a crítica do imaginário masculino de Deus, privilegiamos a produção da teologia feminista e, para o conceito de violência que contem a noção de poder, privilegiamos a concepção de micro-poder, estimando que a violência contra da mulher se concretiza, primordialmente, em nível de micro estruturas, ainda que o fato esteja legitimado em nível de macro estruturas. O objetivo desta tese é contribuir na reflexão teológico-pastoral desde a perspectiva da mulher, visando fornecer elementos de debate no caminho à superação da violência.(AU)
Resumo:
Layered structures, known as micro structures in marine environments are common features of which their formation mechanisms are first reviewed. Some methods of measuring such features based on the measurements and theories are presented for the Persian Gulf. This includes determination of layers with temperature inversion (TI) associated with double diffusive convection (DDC). The relevant associated parameters are estimated from ROPME CTD data for late winter and early summer of 1992. Only in certain parts temperature inversion and DDC are observed which seem to produce layered structures. Observations show that the places with TI and DDC are mainly confined to the frontal regions where the water entering the Persian Gulf and water exiting it meet, nearly along the axis of the Gulf. TI and DDC is mainly observer in the northern bound of the front. Typical density ratio for regions with TI and DDC is 0.7 to 0.2 and the mean depth is at about 37 ± 3 m for the Persian Gulf. TI and DDC are also found in the outflow from the Persian Gulf to the Oman Gulf which is found to be at a depth of about 250 m. Horizontal addiction and reduction of solar heating seem to be the main reasons in producing layers with TI and DDC. It is also found that the regime of DDC in the Persian Gulf is more diffusive and the flow associated with intrusion layers with TI is non-isopycnal (more unstable). However for the Oman sea both diffusive and finger regime are observed and the flow is inferred to be isopycnal (more stable statically). Typical heat and salt fluxes due to DDC are found to be 6 W/m2 and 0.36 W/m2 respectively. Effective salinity diffusivity, Ks and heat diffusivity, Kr have been estimated for the places with DDC in the Persian Gulf and Oman Gulf (Ks=1.1 *10-7 m2/s, KT= 1.88*10-6 m2/s). Their values are within the values obtained by others. The buoyancy frequency for the Persian Gulf with typical mean value of 0.05s-1 is much higher than these of the free Oceans. Such large values of N (typically 0.05 s-1) indicate that processes such as tide can produce strong internal waves which may be another factor in producing layered structures. This requires separate study.
Resumo:
The dynamization of integration processes in Europe has generated numerous research topics for political analysis. Border integration is an expression of the broader unification processes of certain structures. It is also a manifestation of the observation that people think globally, but function locally. The European integration perspective is therefore practically implemented in micro structures, exemplified by border twin towns. The objective of this paper is to revive the micro perspective as a useful approach in the investigation of integration processes. This perspective is applied in the field of border studies, which focus on research into the transformation of European borders resulting from integration processes, as well as on the transformations of the concepts of statehood, territoriality and sovereignty. It is assumed that these phenomena are definitely more observable at the outskirts of states than in their centers. Theoretical and empirical considerations are based on the example of border twin towns, as the European units of local government that integrate across borders. The main differences between the integration of towns in Western Europe and Central and Eastern Europe are also indicated in the analysis.
Resumo:
Conventional catalyzed thermal CVD of carbon microcoils commonly suffers from poor control of the coil shape and morphology and rarely reaches the nanoscale size range. This article reports on an unconventional Ni-P alloy-catalyzed, high-throughput, highly reproducible CVD of ultra-long carbon coil-like micro- and nano-structures using acetylene precursor at relatively low process temperatures. Helical carbon microcoils with consistently uniform, circular cross-sections and a high degree of crystallinity have been synthesized at 750 °C. A further reduction of the temperature to 650 °C led to the growth of ultra-long (up to several mm) wave-like carbon nanofibers made of two nanowires with the diameters in the 100-200 nm range. The results of the XRD and Raman analysis reveal that the nanofibers feature only a slightly more disordered structure compared to the microcoils. Our results suggest that morphology and structure of the carbon coil-like micro- and nano-structures can be tailored by the appropriate alloying of the catalyst and the choice of the CVD process parameters.
Resumo:
A new method based on analysis of a single diffraction pattern is proposed to measure deflections in micro-cantilever (MC) based sensor probes, achieving typical deflection resolutions of 1nm and surface stress changes of 50 mu N/m. The proposed method employs a double MC structure where the deflection of one of the micro-cantilevers relative to the other due to surface stress changes results in a linear shift of intensity maxima of the Fraunhofer diffraction pattern of the transilluminated MC. Measurement of such shifts in the intensity maxima of a particular order along the length of the structure can be done to an accuracy of 0.01mm leading to the proposed sensitivity of deflection measurement in a typical microcantilever. This method can overcome the fundamental measurement sensitivity limit set by diffraction and pointing stability of laser beam in the widely used Optical Beam Deflection method (OBDM).
Resumo:
The growth of neuroblastoma (N2a) and Schwann cells has been explored on polymer derived carbon substrates of varying micro and nanoscale geometries: resorcinol-formaldehyde (RE) gel derived carbon films and electrospun nanofibrous (similar to 200 nm diameter) mat and SU-8 (a negative photoresist) derived carbon micro-patterns. MTT assay and complementary lactate dehydrogenase (LDH) assay established cytocompatibility of RE derived carbon films and fibers over a period of 6 days in culture. The role of length scale of surface patterns in eliciting lineage-specific adaptive response along, across and on the interspacing between adjacent micropatterns (i.e., ``on'', ``across'' and ``off'') has been assayed. Textural features were found to affect 3',5'-cyclic AMP sodium salt-induced neurite outgrowth, over a wide range of length scales: from similar to 200 nm (carbon fibers) to similar to 60 mu m (carbon patterns). Despite their innate randomness, carbon nanofibers promoted preferential differentiation of N2a cells into neuronal lineage, similar to ordered micro-patterns. Our results, for the first time, conclusively demonstrate the potential of RE-gel and SU-8 derived carbon substrates as nerve tissue engineering platforms for guided proliferation and differentiation of neural cells in vitro. (C) 2013 Elsevier Ltd. All rights reserved.
Resumo:
We have studied the optical properties of a series of InGaN/AlInGaN 10-period multiple quantum wells (MQW) with differing well thickness grown by metal-organic vapor-phase epitaxy that emit at around 380 nm. The aim of this investigation was to optimise the room temperature internal quantum efficiency, thus the quantum well (QW) thicknesses were accordingly chosen so that the overlap of the electron/hole wave function was maximised. At low temperature, we observed a reduction of the photo luminescence decay time with decreasing well width in line with the theoretical predictions. For a structure with well thicknesses of 1.5 nm, we measured a photoluminescence internal quantum efficiency of 67% at room temperature with a peak emission wavelength of 382 nm. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
Classes of lattice material are reviewed, and their fracture response is explored in the context of the core of a sandwich panel. Attention is focussed on the strength of a sandwich plate with centre-cracked core made from an elastic-brittle square lattice. Predictions are summarised for the un-notched strength of the sandwiched core and for the fracture toughness of the lattice under remote tension, remote compression or remote shear. It is assumed that the lattice fails when the local stress in the cell walls attains the tensile or compressive strength of the solid, or when local buckling occurs. The local failure mechanism that dictates the unnotched strength may be different from that dictating the fracture toughness. Fracture mechanism maps are generated in order to reveal the dominant local failure mechanism for any given cell wall material.