A ítria vem sendo muito utilizada como material luminescente e estrutural resistente a altas temperaturas, devido às suas excelentes características ópticas e refratárias. No processamento coloidal da ítria, o controle da estabilidade da suspensão consiste em uma importante etapa quando se objetiva produzir componentes reprodutivos, com densidade controlada, microestrutura homogênea e estabilidade estrutural. Desta maneira, os estudos envolvendo o comportamento de superfície, as condições de estabilidade das suspensões e o comportamento frente às condições de conformação (fluxo), fornecem importantes subsídios para controle dos processos na fabricação de componentes cerâmicos para queimadores de gás. Neste sentido, realizaram-se estudos sobre o comportamento de superfície, de estabilidade e reológico de suspensões aquosas de ítria e do concentrado de terras raras contendo ítria a fim de adequá-las para o processo de conformação por impregnação, onde foram testados diferentes materiais orgânicos como matrizes de réplica, para a confecção de membranas porosas para queimadores de gás. Neste estudo foram avaliados os parâmetros como: pH do meio, concentrações de dispersante, sólidos e ligante na estabilidade e no comportamento ao fluxo das suspensões cerâmicas, e também os aspectos dos distintos materiais orgânicos selecionados como matrizes de réplica para impregnação com as suspensões cerâmicas otimizadas. Os resultados obtidos indicam que se pode confeccionar membranas cerâmicas porosas pelo método de réplica a partir das suspensões aquosas de ítria e do concentrado de terras raras contendo ítria, utilizando-se pH alcalino, polieletrólito aniônico e uma tela mista de nylon-algodão como matriz de réplica. / Yttria has been used very much as luminescent and high temperature material due to its excellent optical and refractory characteristics. In yttria colloidal processing, the control of the stability of suspension is an important step in the fabrication of reproducible products with controlled density, homogeneous microstructure and structural stability. So, the studies concerning surface behavior, stability conditions of the suspensions and the behavior under conformation conditions (flow), give important information for the control of fabrication process of ceramic components for gas burners. In this way, studies concerning surface behavior, stability and rheology of aqueous suspensions of yttria and rare earth concentrate containing yttria were carried out, in order to adequate them for impregnation method, where different organic materials were tested as replica matrix to fabricate porous membranes for gas burners. In this study, the effect of some parameters as pH and concentrations of dispersant, solids and binder on stability and flow behavior of ceramic suspensions were evaluated, and also, different kinds of organic materials selected as replica matrix for impregnation method using optimized ceramic suspensions. The results show that porous ceramics membranes can be produced by replica using yttria and rare earth concentrate containing yttria, using alkaline pH, anionic polyelectrolyte and a nylon-cotton cloth as replica matrix.

The aim of this thesis is to examine the poetics of postmodernism and explore to what extend were the dystopian novels London Fields (1989) by Martin Amis and England, England (1998) by Julian Barnes influenced by this concept. The first part of the work deals with the biographies of the authors, dystopian features of both books and the theory of postmodernism. The second part focuses on practical analyses of both novels. In the second part, the thesis theoretically introduces various concepts of postmodernism and then practically illustrates them on the works.

A ítria vem sendo muito utilizada como material luminescente e estrutural resistente a altas temperaturas, devido às suas excelentes características ópticas e refratárias. No processamento coloidal da ítria, o controle da estabilidade da suspensão consiste em uma importante etapa quando se objetiva produzir componentes reprodutivos, com densidade controlada, microestrutura homogênea e estabilidade estrutural. Desta maneira, os estudos envolvendo o comportamento de superfície, as condições de estabilidade das suspensões e o comportamento frente às condições de conformação (fluxo), fornecem importantes subsídios para controle dos processos na fabricação de componentes cerâmicos para queimadores de gás. Neste sentido, realizaram-se estudos sobre o comportamento de superfície, de estabilidade e reológico de suspensões aquosas de ítria e do concentrado de terras raras contendo ítria a fim de adequá-las para o processo de conformação por impregnação, onde foram testados diferentes materiais orgânicos como matrizes de réplica, para a confecção de membranas porosas para queimadores de gás. Neste estudo foram avaliados os parâmetros como: pH do meio, concentrações de dispersante, sólidos e ligante na estabilidade e no comportamento ao fluxo das suspensões cerâmicas, e também os aspectos dos distintos materiais orgânicos selecionados como matrizes de réplica para impregnação com as suspensões cerâmicas otimizadas. Os resultados obtidos indicam que se pode confeccionar membranas cerâmicas porosas pelo método de réplica a partir das suspensões aquosas de ítria e do concentrado de terras raras contendo ítria, utilizando-se pH alcalino, polieletrólito aniônico e uma tela mista de nylon-algodão como matriz de réplica. / Yttria has been used very much as luminescent and high temperature material due to its excellent optical and refractory characteristics. In yttria colloidal processing, the control of the stability of suspension is an important step in the fabrication of reproducible products with controlled density, homogeneous microstructure and structural stability. So, the studies concerning surface behavior, stability conditions of the suspensions and the behavior under conformation conditions (flow), give important information for the control of fabrication process of ceramic components for gas burners. In this way, studies concerning surface behavior, stability and rheology of aqueous suspensions of yttria and rare earth concentrate containing yttria were carried out, in order to adequate them for impregnation method, where different organic materials were tested as replica matrix to fabricate porous membranes for gas burners. In this study, the effect of some parameters as pH and concentrations of dispersant, solids and binder on stability and flow behavior of ceramic suspensions were evaluated, and also, different kinds of organic materials selected as replica matrix for impregnation method using optimized ceramic suspensions. The results show that porous ceramics membranes can be produced by replica using yttria and rare earth concentrate containing yttria, using alkaline pH, anionic polyelectrolyte and a nylon-cotton cloth as replica matrix.

This is a problem of sampling. The number of classical states of an N-body system grows with O( 3 ^ N ). To sample this space, advanced techniques are required. Replica Exchange (RE), also known as parallel tempering, is an example that uses parallelization, and Hamiltonian Replica Exchange is a subset of RE that scales the energy of the replicas. The number of simulations required grows at O( N^(1/2) ), where N is number of atoms in the system. Replica Exchange with Dynamical Scaling (REDS) attempts to address this problem to decrease computational cost. It has been shown to increase efficiency 10-fold. We implemented REDS in GROMACS 2018. (Abraham 2015) All changes to the source code were written in the form of parallel methods. Scripts were written in Python and Perl to automate the experiment entirely. An exchange connects a region of high energy space, far above the surface of the landscape, to low energy space, which approaches the surface of the landscape, which represents the natural conformational progression of the molecule. Using REDS we were able to achieve exchanges at temperatures spaced too far apart to exchange using normal RE. Ergo, the flexibility of dynamical scaling allowed regions of phase space that would have gone unsampled to be mapped, addressing our initial problem of sampling.

Embedded memories dominate area, power and cost of modern very large scale integrated circuits system on chips ( VLSI SoCs). Furthermore, due to process variations, it becomes challenging to design reliable energy efficient systems. Therefore, fault-tolerant designs will be area efficient, cost effective and have low power consumption. The idea of this project is to design embedded memories where reliability is intentionally compromised to increase storage density. Gain cell memories are smaller than SRAM and unlike DRAM they are logic compatible. In multilevel DRAM storage density is increased by storing two bits per cell without reducing feature size. This thesis targets multilevel read and write schemes that provide short access time, small area overhead and are highly reliable. First, timing analysis of reference design is performed for read and write operation. An analytical model of write bit line (WBL) is developed to have an estimate of write delay. Replica technique is designed to generate the delay and track variations of storage array. Design of replica technique is accomplished by designing replica column, read and write control circuits. A memory controller is designed to control the read and write operation in multilevel DRAM. A multilevel DRAM is with storage capacity of eight kilobits is designed in UMC 90 nm technology. Simulations are performed for testing and results are reported for energy and access time. Monte Carlo analysis is done for variation tolerance of replica technique. Finally, multilevel DRAM with replica technique is compared with reference design to check the improvement in access times.

In this study, we synthesized amphiphilic block copolymer Poly(ethylene glycol)-b-Poly(£`-caprolactone) (PEO-b-PCL), and the mesoporous silica and phenolic were synthesized by using EISA (evaporation induced self-assembly) strategy. The mesoporous carbon also obtained after carbonization. After incorporating the precursors into the mesoporous channels through incipient wetness impregnation and further hydrogen reduction, 3D body-centered cubic (BCC) metal network/silica, metal nanowires/silica, metal/phenolic, and metal/carbon nanocomposites could be obtained. Moreover, metal replica was obtained through HF etching. Transmission electron microscope (TEM) and the small angle X-ray scattering (SAXS) patterns indicate that the parent ordered mesoporous structure was well-maintained during the synthesis process. The X-ray diffraction (XRD) and selected-area electron diffraction (SAED) demonstrate that Pd and Ag were reduced within the channels of mesoporous materials. The pore size distribution and BET surface area of mesoporous materials and metal/mesoporous materials composite were recorded by N2 isotherm adsorption-desorption experiment. In the future, we expect that the mesoporous metal and mesoporous nanocomposite with specific morphologies behave excellent performance in various applications, such as catalysis, gas sensors, nano electronic/optical devices and medical diagnosis.

In this study, the PDMS with microgroove structure was used controlling pretilt anlge of liquid crystal. Polydimethylsiloxane, also called PDMS, is one transparent, flexible, and stable material. It was usually fabricated the flexible display and so on. Based on Groove Theory, we can create the microgroove structure with the different groove depths and the width of the lines on PDMS by Replica Molding Method, in order to controlling the pretilt anlge of liquid crystal. We used the photoresist with different thickness to developing, and then the groove will get with different depth of groove. The PDMS was injected to the surface of groove with slow motion. When the liquid-like PDMS was curing, the PDMS can readily convert into solid elastomers by cross-linking. Finally, The microgrooved PDMS structure will obtain.

Multi-domain Vertical Alignment Flexible Liquid Crystal Display based on photolithography and replica-Molding method has been demonstrated. In order to maintain a uniform cell gap between flexible substrate,the microstructures were fabricated with polydimethylsiloxane (PDMS) material by replica-molding method. The microstructures master were designed and fabricated using a photosensitive resin (SU-8) by photolithography. The microstructures of pixel-encapsulated walls enhance the mechanical strength to prevent the liquid crystal molecules flow in the bend state deformations. Besides, the elastomeric material, PDMS, provide weak surface energy and induce vertical alignment for liquid crystal spontanelusly without any surface treatment. The microstructure protrusions made by PDMS can provide multi-domain vertical alignment (MVA) effect with wide viewing angle and high contrast ratio. Therefore, this method could be implemented for achieving multi-domain vertical alignment on a flexible LCD applications. The flexible LCD have great stability reproducibility, durability and good electro-optical performances.

Made available in DSpace on 2014-12-17T14:02:01Z (GMT). No. of bitstreams: 1 ClovisCMN_DISSERT.pdf: 5818317 bytes, checksum: 71340e95f66a43118e689e2a248f3dd3 (MD5) Previous issue date: 2011-11-26 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Os perciformes constituem o maior e mais diversificado grupo de peixes. Uma parcela consider?vel de suas esp?cies apresenta um marcante conservadorismo cromoss?mico exibindo um padr?o caracterizado por 2n=48a, NF=48, que tem sido apontado como uma condi??o basal para a Ordem. Blocos heterocrom?ticos reduzidos e RONs simples s?o caracter?sticos para este grupo de peixes. No entanto, n?o se encontra ainda bem estabelecido se este conservadorismo se deve, em parte, a dados provenientes de bandamentos cromoss?micos pouco resolutivos, como os convencionalmente utilizados nas caracteriza??es citogen?ticas das esp?cies marinhas ou a uma condi??o peculiar cariot?pica deste grupo. Visando clarificar os processos envolvidos no peculiar conservadorismo cromoss?mico observado nesta Ordem, cinco esp?cies da fam?lia Haemulidae foram submetidas ? variadas t?cnicas citogen?ticas como colora??o com Giemsa, bandamento C e impregna??o por nitrato de prata, bem como digest?o com enzimas de restri??o (AluI, TaqI, PstI e EcoRI), bandamento de replica??o pela incorpora??o do an?logo de base 5 BrdU, colora??o com os fluorocromos CMA3/MM e DAPI, double FISH com sondas para as subunidades ribossomais 5S e 45S, sendo tamb?m analisadas morfometricamente atrav?s de morfometria geom?trica (MG). Os dados obtidos permitiram identificar um alto grau de similaridade cariot?pica neste grupo independente do n?vel de resolu??o das t?cnicas utilizadas. As esp?cies Conodon nobilis, Pomadasys corvinaeformis, Haemulon aurolineatum, H. plumierii e H. steindachneri apresentaram uma macroestrutura cariot?pica comum composta por 2n=48a (NF=48), com RONs simples localizadas em um mesmo par cromoss?mico (24? par) nas esp?cies C. nobilis, H. aurolineatum H. plumierii e H. steindachneri e em outro par em P. corvinaeformis (18? par), considerando-se estas regi?es caracteres citotaxon?micos pouco importantes. O padr?o heterocrom?tico apresentou-se similar para todas as esp?cies, observando-se reduzidos blocos heterocrom?ticos detectados preferencialmente em regi?o centrom?ricas e em menor n?mero em regi?es pericentrom?ricas e telom?ricas. Contrastando com a reduzida diferencia??o cromoss?mica observada, as an?lises por MG indicaram uma consp?cua diferencia??o morfol?gica entre as esp?cies. Condi??es ambientais com reduzidas barreiras biogeogr?ficas, caracter?sticas biol?gicas, decorrente da presen?a de grandes contingentes populacionais uniformemente distribu?dos em largas ?reas costeiras, que promoveriam a manuten??o do fluxo g?nico dentro das popula??es, associadas ?s caracter?sticas cariot?picas peculiares, poderiam desempenhar uma a??o sin?rgica contribuindo para a evolu??o bradit?lica do cari?tipo nas esp?cies de Haemulidae

Polymers that undergo dramatic changes in structural conformations in response to numerous stimuli such as temperature, pH, electric and magnetic fields, light inten- sity, biological molecules, and solvent polarity, are known as stimuli-responsive or ”smart” polymers. There is a broad range of very promising applications of these materials in catalysis, environmental remediation, sensors or actuator systems, and as delivery systems of therapeutic agents. Researchers have been trying to mimic smart polymers based on properties of polymers found in nature such as proteins, carbohydrates and nucleic acids. Novel bio-compatible polymers with a variety of chemical functional groups, diverse topologies, and cross-linking patterns with the ability to self-assemble in vivo are being engineered. Experimental and theoretical studies indicate that the thermodynamic properties relating to the hydrophobic effects play a pivotal role in determining the self-assembly process in smart polymers. At the same time, computational approaches based on simulation and modeling provide an understanding of this phenomenon on the micro- scopic level. Building empirical models based on statistical mechanics methods and simulation data helps to design polymeric materials with desirable traits. My research is mainly focused on investigating physicochemical characteristics of stimuli-responsive polymers under different conditions. I used atomistic molecular dynamics simulations to investigate these effects on polymer conformation. Given the size and complexity of our polymeric systems, we employed Graphical Process- ing Units (GPU) and enhanced sampling techniques such as REDS2 to increase the sampling time. These methods allow for the study of polymeric structural dynamics in solvents of varying polarity and in human skin epidermis. Our constant pH simulation of poly(methacrylic acid) revealed that the overall response is made up of local and global structural changes. The local structural re- sponse depends on the tacticity of the polymer, which leads to distinct cooperative effects for polymers with varying stereochemistry. Such simulations help to under- stand the principal driving forces behind the mechanism of self-assembly processes.