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Ghorbanzadeh, Mohammad. "Resource Allocation and End-to-End Quality of Service for Cellular Communications Systems in Congested and Contested Environments." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/64390.
Full textAbstract:
This research addresses the concept of radio resource allocation for cellular communications systems operating in congested and contested environments with an emphasis on end-to-end quality of service (QoS). The radio resource allocation is cast under a proportional fairness formulation which translates to a convex optimization problem. Moreover, the resource allocation scheme considers subscription-based and traffic differentiation in order to meet the QoS requirements of the applications running on the user equipment in the system. The devised resource allocation scheme is realized through a centralized and a distributed architecture and solution algorithms for the aforementioned architectures is derived and implemented in the mobile devices and the base stations. The sensitivity of the resource allocation scheme to the temporal dynamics of the quantity of the users in the system is investigated. Furthermore, the sensitivity of the resource allocation scheme to the temporal dynamics in the application usage percentages is accounted for. In addition, a transmission overhead of the centralized and distributed architectures for the resource allocation schemes is performed. Furthermore, the resource allocation scheme is modified to account for a possible additive bandwidth done through spectrum sharing in congested and contested environments, in particular spectrally coexistent radar systems. The radar-spectrum additive portion is devised in a way to ensure fairness of the allocation, high bandwidth utilization, and interference avoidance. In order to justify the aforesaid modification, the interference from radar systems into the Long Term Evolution (LTE) as the predominant 4G technology is studies to confirm the possibility of the spectrum sharing. The preceding interference analysis contains a detailed simulation of radar systems, propagation path loss models, and a third generation partnership project compliant LTE system. The propagation models are Free Space Path Loss (FSPL) and Irregular Terrain Model (ITM). The LTE systems under consideration are macro cell, outdoor small cells, and indoor small cells. Furthermore, the resource allocation under channel consideration is formalized such that the resources are allocated under a congested environment and based on the quality of channel the users have in the network as well as the quality of service requirements of the applications running on the mobile devices.Ph. D.
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Rashtian, Hooman. "On the use of body biasing to improve the performance of CMOS RF front-end building blocks." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44723.
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Body biasing is commonly used in digital and low-power analog integrated circuits to adjust the threshold voltage of complementary metal-oxide-semiconductor (CMOS) transistors and to lower the supply voltage. In this work, the application of body biasing to improve the performance of four of the main building blocks of CMOS radio-frequency (RF) front-ends is explored. Here, the body-biasing technique is used in conjunction with other design techniques and provides an extra degree of freedom in the design of CMOS RF front-end building blocks including low-noise amplifiers (LNAs), active down-conversion mixers, voltage-controlled oscillators (VCOs), and power amplifiers (PAs). The performance improvements are mainly related to noise and linearity of these building blocks and have been achieved through adjusting the values of the bulk-source transconductance, the source-bulk capacitance, and the threshold voltage of the MOS transistors. Body biasing is applied in multi-stage LNAs to improve their noise figure and linearity as well as to adjust the gain. Body biasing is used to improve the linearity of active down-conversion mixers with gradual LO switching by enhancing the linearity of the LO stage. Body biasing is used in cross-coupled LC VCOs to improve their phase noise performance by forward body biasing of core transistors which lowers the duty cycle in class-C mode of operation. In active-inductor-based LC VCOs, body biasing is used to increase the tuning range of active inductors and thus the oscillation frequency. Finally, body biasing is in the predistortion stage of class-AB PAs to improve the linearity by compensating for the voltage-dependent nonlinear gate-source capacitance of the input transistor of the PA. In all cases, these improvements are achieved with minimal overhead on circuit-level complexity and power consumption of the overall system. The proposed applications of body-biasing technique are validated through measurements on different proof-of-concept prototypes fabricated in 0.13-µm, 90-nm, and 65-nm CMOS technologies.
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Kraemer, Michael. "Design of a low-power 60 GHz transceiver front-end and behavioral modeling and implementation of its key building blocks in 65 nm CMOS." Phd thesis, INSA de Toulouse, 2010. http://tel.archives-ouvertes.fr/tel-00554674.
Full textAbstract:
Worldwide regulations for short range communication devices allow the unlicensed use of several Gigahertz of bandwidth in the frequency band around 60 GHz. This 60GHz band is ideally suited for applications like very high data rate, energy-autonomous wireless sensor networks or Gbit/s multimedia links with low power constraints. Not long ago, radio interfaces that operate in the millimeter-wave frequency range could only be realized using expensive compound semiconductor technologies. Today, the latest sub-micron CMOS technologies can be used to design 60GHz radio frequency integrated circuits (RFICs) at very low cost in mass production. This thesis is part of an effort to realize a low power System in Package (SiP) including both the radio interface (with baseband and RF circuitry) and an antenna array to directly transmit and receive a 60GHz signal. The first part of this thesis deals with the design of the low power RF transceiver front-end for the radio interface. The key building blocks of this RF front-end (amplifiers, mixers and a voltage controlled oscillator (VCO)) are designed, realized and measured using the 65nm CMOS technology of ST Microelectronics. Full custom active and passive devices are developed and characterized for the use within these building blocks. An important step towards the full integration of the RF transceiver front-end is the assembly of these building blocks to form a basic receiver chip. Circuits with small chip size and low power consumption compared to the state of the art have been accomplished. The second part of this thesis concerns the development of behavioral models for the designed building blocks. These system level models are necessary to simulate the behavior of the entire SiP, which becomes too complex when using detailed circuit level models. In particular, a novel technique to model the transient, steady state and phase noise behavior of the VCO in the hardware description language VHDL-AMS is proposed and implemente d. The model uses a state space description to describe the dynamic behavior of the VCO. Its nonlinearity is approximated by artificial neural networks. A drastic reduction of simulation time with respect to the circuit level model has been achieved, while at the same time maintaining a very high level of accuracy.
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Kraemer, Michael M. "Design of a low-power 60 GHz transceiver front-end and behavioral modeling and implementation of its key building blocks in 65 nm CMOS." Thesis, Toulouse, INSA, 2010. http://www.theses.fr/2010ISAT0027/document.
Full textAbstract:
La réglementation mondiale, pour des appareils de courte portée, permet l’utilisation sans licence de plusieurs Gigahertz de bande autour de 60 GHz. La bande des 60 GHz répond aux besoins des applications telles que les réseaux de capteurs très haut débit autonome en énergie,ou les transmissions à plusieurs Gbit/s avec des contraintes de consommation d’énergie. Il y a encore peu de temps, les interfaces radios fonctionnant dans la bande millimétrique n’étaient réalisables qu’en utilisant des technologies III-V couteuses. Aujourd’hui, les avancées des technologies CMOS nanométriques permettent la conception et la production en masse des circuits intégrées radiofréquences (RFIC) à faible coût.Cette thèse s’inscrit dans des travaux de recherches dédiés à la réalisation d’un système dans un boîtier (SiP, System in Package) à 60 GHz contenant à la fois l’interface radio (bande de base et circuits RF) ainsi qu’un réseau d’antennes. La première partie de cette thèse est dédiée la conception de la tête RF de l’émetteur-récepteur à faible consommation pour l’interface radio. Les blocs clefs de cette tête RF (amplificateurs, mélangeurs et un oscillateur commandé en tension) sont conçus, réalisés et mesurés en utilisant la technologie CMOS 65 nm de ST Microelectronics. Des éléments actifs et passifs sont développés spécifiquement pour l’utilisation au sein de ces blocs. Une étape importante vers l’intégration de la tête RF complète de l’émetteur-récepteur est l’assemblage de ces blocs de base afin de réaliser une puce émetteur et une puce récepteur. A ce but, une tête RF pour le récepteur a été réalisée. Ce circuit présent une consommation et un encombrement plus réduit que l’état de l’art.La deuxième partie de cette thèse présente le développement des modèles comportementaux des blocs de base conçus. Ces modèles au niveau système sont nécessaires afin de simuler le comportement du SIP, qui devient trop complexe si des modèles détaillés du niveau circuitsont utilisés. Dans cette thèse, une nouvelle technique modélisant le comportement en régime transitoire et régime permanent ainsi que le bruit de phase des oscillateurs commandés en tension est proposée. Ce modèle est implémenté dans le langage de description de matérielVHDL-AMS. La technique proposée utilise des réseaux de neurones artificiels pour approximer la caractéristique non linéaire du circuit. La dynamique est décrite dans l’espace d’état. Grâce à ce modèle, il est possible de réduire d’une façon drastique le temps de calcul des simulations système tout en conservant une excellente précisionWorldwide regulations for short range communication devices allow the unlicensed use of several Gigahertz of bandwidth in the frequency band around 60GHz. This 60GHz band is ideally suited for applications like very high data rate, energy-autonomous wireless sensor networks or Gbit/s multimedia links with low power constraints. Not long ago, radio interfaces that operate in the millimeter-wave frequency range could only be realized using expensive compound semiconductor technologies. Today, the latest sub-micron CMOS technologies can be used to design 60GHz radio frequency integrated circuits (RFICs)at very low cost in mass production. This thesis is part of an effort to realize a low power System in Package (SiP) including both the radio interface (with baseband and RF circuitry) and an antenna array to directly transmit and receive a 60GHz signal. The first part of this thesis deals with the design of the low power RF transceiver front-end for the radio interface. The key building blocks of this RF front-end (amplifiers, mixers and a voltage controlled oscillator (VCO)) are designed, realized and measured using the 65nm CMOS technology of ST Microelectronics. Full custom active and passive devices are developed for the use within these building blocks. An important step towards the full integration of the RF transceiver front-end is the assembly of these building blocks to form basic transmitter and receiver chips. Circuits with small chip size and low power consumption compared to the state of the art have been accomplished.The second part of this thesis concerns the development of behavioral models for the designed building blocks. These system level models are necessary to simulate the behavior of the entire SiP, which becomes too complex when using detailed circuit level models. In particular, a novel technique to model the transient, steady state and phase noise behavior of the VCO in the hardware description language VHDL-AMS is proposed and implemented. The model uses a state space description to describe the dynamic behavior of the VCO. Its nonlinearity is approximated by artificial neural networks. A drastic reduction of simulation time with respect to the circuit level model has been achieved, while at the same time maintaining a very high level of accuracy
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Lee, Minjae. "Design, Synthesis and Self-Assembly of Polymeric Building Blocks and Novel Ionic Liquids, Ionic Liquid-Based Polymers and Their Properties." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77166.
Full textAbstract:
The convergence of supramolecular and polymer sciences has led to the construction of analogs of traditional covalently-constructed polymeric structures and architectures by supramolecular methods. Host-guest complexations of polymers are also possible through well-defined synthesis of polymeric building blocks, for novel supramolecular polymers.
Monotopic polymeric building blocks were synthesized by controlled radical polymerizations with a crown or paraquat initiator. The combinations of terminal and central functionalities of host and guest polymeric building blocks provided chain-extended and tri-armed homopolymers, and diblock and tri-armed copolymers.
A supramolecular graft copolymer was formed from a main-chain poly(ester crown ether) and a paraquat terminated polystyrene. This comb-like copolymer was characterized by a large viscosity increase. A four-armed polystyrene-b-poly(n-butyl methacrylate) was synthesized from a pseudorotaxane macroinitiator derived from a complex of a crown-centered polystyrene and a dufunctional paraquat compound. A single peak with higher molecular weight from size exclusion chromatography proved the copolymer formation.
Supramolecular interactions enhance the ionic conductivity of semi-crystalline ionic polymers; the ionic conductivity of a C₆-polyviologen and dibenzo-30-crown-10 mixture was 100 times higher than the polyviologen itself. However, ionic conductivities of amorphous polyviologens with polyethers were influenced only by glass transition temperature changes.
New imidazolium ionic liquid monomers and imidazolium based polymers were synthesized for potential applications in electroactive devices, such as actuators. Structure-property relationships for pendant imidazolium polyacrylates and main-chain imidazolium polyesters were investigated. Terminal ethyleneoxy moeties enhanced ionic conduction 2~3 times; however, the alkyl chain length effect was negligible. For the imidazoium polyesters, higher ion conductivities result from 1) mono-imidazolium over bis-imidazolium, and 2) bis(trifluoromethanesulfonyl)imide polymers over hexafluorophosphate analogs. A semi-crystalline hexafluorophosphate polyester with C₁₀-sebacate-C₁₀, displayed 400-fold higher ionic conductivity than the amorphous C₆-sebacate-C₆ analogue, suggesting the formation of a biphasic morphology in the former polyester.
New dicationic imidazolium salts have interesting features. 1,2-Bis[N-(N'-alkylimidazoilum)]ethane salts stack well in the solid state and possess multiple solid-solid phase transitions. They complex with dibenzo-24-crown-8 and a dibenzo-24-crown-8 based pyridyl cryptand with Ka = ~30 and 360 M¹, respectively. Some of these dicationic imidazolium salts have low entropies of fusion, typical of plastic crystals.
These newly discovered imidazolium homopolymers have ionic conductivities up to 10⁴ (S cm⁻¹); however, better properties are still required. Well-designed block copolymers should provide both good electrical and mechanical properties from bicontinuous morphologies, such ion channels.Ph. D.
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Logullo, Bárbara Gonçalves. "Influência do graute e da taxa de armadura no comportamento da alvenaria de blocos de concreto /." Ilha Solteira : [s.n.], 2006. http://hdl.handle.net/11449/91493.
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Orientador: Jefferson Sidney CamachoBanca: Jorge Luis Akasaki
Banca: João Bento de Hanai
Resumo: Apresenta-se neste trabalho uma investigação experimental do comportamento da alvenaria estrutural de blocos de concreto, resistência à compressão axial e módulo de elasticidade, em função do emprego de blocos de diferentes resistências, na presença de grautes de resistências variadas e também da existência ou não de armaduras, aplicadas em distintas taxas. Desse modo, são apresentados e comentados os resultados de ensaios de compressão axial em unidades, prismas de três blocos e pequenas paredes, montados com um só tipo de argamassa, mas com blocos de duas resistências distintas, designadas B1 e B2. Os elementos ensaiados são vazios e também preenchidos com grautes de duas resistências, definidas G1 e G2. Além destes, também são ensaiados prismas e paredes armadas, com taxas de armadura ñ 1, ñ 2 e ñ 3. Portanto, são realizados ensaios em prismas e paredes vazias, prismas e paredes grauteadas com as diferentes combinações de classes de bloco e graute e com a combinação de blocos, grautes e taxas de armadura. Com os resultados obtidos foi verificado que o grauteamento praticamente dobrou a resistência do prisma grauteado, e, nas paredes o acréscimo foi médio de 80%, comparado com prisma e parede vazia na área bruta, porém esse aumento não foi proporcional à relação efetiva de áreas. Os prismas grauteados apresentaram diminuição na deformação de ruptura com a utilização de grautes mais rígidos, e, o grauteamento homogeneizou o comportamento de deformabilidade da alvenaria e do bloco que a constitui, no prisma e na parede. Constatou-se, também, que as armaduras não alteraram o comportamento estrutural dos prismas e paredes, nem na sua resistência à compressão axial e nem na sua deformabilidade.
Abstract: It is presented in this work an experimental investigation of the structural mansory of concrete blocks behavior, resistance to axial compression and elastic modulus, in function of the utilization of blocks of different resistances, with the presence of grout of varying resistances and the existance or not of armour, applied in distinct taxes. By this way, it's shown and commented the trials results of axial compression in units, three-block prisms and small walls, manufactured with just one type of mortar, but with blocks with two distincts resistances, called B1 and B2. The tested elements are empty and filled with grout of two resistances, defined as G1 and G2. Besides them, armoured prism and walls were tested too, with armour taxes called ñ 1, ñ 2 and ñ 3. Hence, the trials are executed in empty prisms and walls, grouted prisms and walls with the different combinations of classes of blocks and grouts and with the combination of blocks, grouts and armour taxes. With the obtained results, it was verified that the grout almost doubled the resistance of the grouted prism and, in walls there was an 80% increase, compared with empty prism and walls in brute area, although this increase was not proportional to the effective relation of areas. The grouted prisms presented a decrease in rupture deformation with the utilization of more rigid grouts, and the grout smoothed the deformability behaviour in mansory and in the block that form it, in prisms and walls. It was noticed too, that the armour do not alter the structure behavior of prisms and walls, not even in theirs resistance to axial compression force, neither to theirs deformability.
Mestre
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Escurra, Jorge Jose. "Optimal Irrigation Management for Sloping Blocked-End Borders." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/214.
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A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m3/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m). To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase simulation which uses the four-point implicit solution method of the Saint-Venant equations, with an algorithm that changes the spatial and temporal weighting, in addition to an algorithm that handles the water depth profile at the blocked-end downstream boundary upon completion of the advance phase; (2) simultaneous advance-recession-phase calculations using a hybrid algorithm to solve the governing equations; and (3) recession-phase simulation using the four-point implicit method until (and if) divergence occurs, then the volume-method is applied to complete the simulation. The three parts also involve the use of computational grid management algorithms and a parabolic equation which defines the Chezy coefficient as a function of water depth. The model incorporates the downhill simplex optimization method to determine the recommended inflow rate and irrigation cutoff time, maximizing a composite irrigation efficiency (water requirement efficiency and application efficiency). Different optimum values of inflow rate and irrigation cutoff time for a range of longitudinal slopes, border lengths, and soil types were generated. Most of the optimum values are for relatively high inflow rate and rapid cutoff time. In addition, exponential relations were developed, based on the simulation results, to determine the best irrigation time for maximization of the composite irrigation efficiency for specified, non-optimal inflow rates. The exponential relations are particularly useful in practice when it is not feasible to use the optimum inflow rate due to constraints at the water source, or because of irrigation scheduling issues.
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Felipe, Alexsandro dos Santos. "Contribuição para a otimização de traços de concreto utilizados na produção de blocos estruturais /." Ilha Solteira : [s.n.], 2010. http://hdl.handle.net/11449/91466.
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Resumo: Diante do grande crescimento da alvenaria estrutural no país, muitas fábricas de blocos de concreto vieram por necessidade, buscar por otimizações do seu processo produtivo, visto que, projetos mais arrojados, acabam exigindo maiores controles de qualidade. A proposta deste estudo é melhorar a produção destes artefatos de concreto por meio de otimizações simples que reduzem o custo e garantem uma produção eficiente na fábrica. Estudar a fundo os vários parâmetros de formação de um traço de concreto seco, tais como coesão, textura, energias de adensamento e resistência à compressão axial, todos os fenômenos dependentes entre si, torna-se muito complexo se avaliado em um único trabalho. No entanto, propor um estudo que colete informações apresentadas por vários autores, facilita na otimização e criação de uma pesquisa que possa contribuir na dosagem para concretos secos, em especial, na fabricação de blocos estruturais. Neste estudo, adaptaram-se para laboratório alguns equipamentos de uso comum para confecção destes artefatos de concreto, possibilitando a correlação direta de corpos de prova cilíndricos com os blocos. Uma das adaptações é o estudo baseado na padronização da energia de compactação, proporcionada pelo equipamento para ensaios de mini-proctor, simulando assim, a máquina vibro-prensa. Outras correlações como coesão e resistência à compressão, também foram possíveis de obter no laboratório, reduzindo então, as interferências constantes no processo produtivo da fábrica, ocasião verificada em vários outros estudos. Diante do exposto, foi possível avaliar com boa segurança os resultados. O estudo foi desenvolvido em três etapas, sempre buscando a maior massa específica seca compactada da mistura de agregados, inicialmente na primeira etapa, foi utilizado somente dois agregados (areia fina e pedrisco), conforme... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: Given the substantial growth of structural masonry in Brazil, many concrete block companies have seen the need to optimize their production process, since more challenging projects require greater quality control. This study proposes to improve the production of concrete artifacts by means of simple optimizations that reduce costs and ensure the company's efficient production. Studying in depth the various parameters of the formation of dry concrete trace, such as cohesion, texture, density energy and axial compressive strength, all the particularities interdependent on one another become very complex when assessed in a single study. However, proposing a study that collects the information submitted by various authors, expedites optimizing and creating a research study which may assist in improving the dosage for dried concrete, particularly in the manufacture of structural blocks. In this study, some commonly used manufacturing equipment, such as concrete artifacts, were laboratory-adapted, enabling a direct correlation of the cylindrical specimens with the blocks. One of the adjustments is the study based on the standardization of compaction energy, provided by the mini-proctor testing equipment, thus simulating the vibro press machine. Other correlations such as cohesion and compressive strength were also obtained in the laboratory, therefore reducing the constant interferences in the plant's production process, observed in many other studies. In this manner, it was possible to reliably assess the results. The study was conducted in three stages, always seeking the highest compressed dry specific mass of the mixture of aggregates. In the first stage, only two aggregates were used (fine sand and pebbles), commonly used at the plant. The second stage included adding the coarse sand and stone powder to correct the lack of resistance promoted by the high amount of fine sand from... (Complete abstract click electronic access below)
Orientador: Jefferson Sidney Camacho
Coorientador: Maria da Consolação F. de Albuquerque
Banca: Jorge Luís Akasaki
Banca: Paulo César Primo Agostinho
Mestre
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Silva, Ana Flávia da. "Avaliação da resistência à compressão da alvenaria estrutural /." Ilha Solteira : [s.n.], 2007. http://hdl.handle.net/11449/91473.
Full textAbstract:
Orientador: Jefferson Sidney CamachoBanca: Rogério de Oliveira Rodrigues
Banca: Paulo César Primo Agostinho
Resumo: Atualmente, a construção em alvenaria estrutural toma como base para determinação da resistência das paredes, a resistência de corpos-de-prova prismáticos, constituídos por dois blocos. Este tipo de ensaio é especificado por norma, mas apresenta problemas já bastante conhecidos, como a alteração do valor de sua resistência devido ao confinamento causado pelos pratos da prensa. Esta mesma norma também especifica o ensaio de paredes em tamanho real, que são tão onerosos e de difícil execução, que são poucos os laboratórios capazes de realizá-los. Para complementar as indicações feitas pela norma brasileiras, os laboratórios de pesquisa utilizam outros tipos de corpo-de-prova, como o prisma de três blocos, que atende às necessidades de praticidade sem apresentar a inconveniência da alteração no valor de sua resistência devido ao confinamento pelos pratos da prensa. Mas este corpo-de-prova ainda está longe de representar fielmente a alvenaria final, sendo sua resistência maior que a da parede. Com o presente trabalho deseja-se investigar, de forma ampla, a resistência à compressão e a deformação da alvenaria estrutural de blocos de concreto, utilizando-se de diferentes tipos de corpos-de-prova, compostos por blocos e argamassas de diferentes resistências. Foram utilizados dois tipos de blocos e quatro tipos de argamassas. Estas últimas podem ser divididas, segundo à sua origem, em mistas e industrializadas. Para analisar a influência do tipo de argamassa, foi definido que uma das argamassas industrializadas tivesse resistência próxima a de uma das mistas. Os corpos-de-prova utilizados foram: prisma de dois blocos, prisma de três blocos, painel de (45x60) cm, painel de (90x100) cm e parede de (90x240) cm. Portanto, foram realizadas várias séries de ensaio, com a combinação dos três fatores condicionantes: geometria do corpo-de-prova, resistência... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Currently, the strength of the structural masonry is based on the strength of prismatic specimens, built by two blocks. This type of test is specified by a Brazilian standard, but it presents some problems, such as the alteration of its strength value due to the confinement caused by the machine plates. The same standard also specifies the test of walls in real size, but they are too expensive and its execution is very difficult, so few laboratories are able to carry them out. Trying to attenuate such reality, research centers use other types of specimens, such as the prism of three blocks, which is easy to build and doesn't present the inconvenience of the alteration of its strength value due to the confinement caused by the machine plates. But this kind of specimen is still far from representing, satisfactorily, the masonry: its strength is quite bigger than the masonry one. In this context, the present work aim to investigate, widely, the compressive strength and the deformation of the concrete structural masonry, using different types of specimens, built by blocks and mortars with different strengths. Two types of blocks and four types of mortars were used. These last ones can be divided, according to its origin, in mixing and industrialized. In order to analyze the influence of the type of mortar, it was defined that the strength of one of the industrialized mortar had to be next to one of the mixing. The specimens used were: prism of two blocks, prism of three blocks, panel of (45x60) cm, panel of (90x100) cm and wall of (90x240) cm. Therefore, many series of tests were carried out, with the combination of the three factors: type of specimen, block strength and mortar strength. The results were compared with values found in literature in order to conclude new trends or to reaffirm old theories about the efficiency interval of concrete structural masonry. The deformation was... (Complete abstract click electronic access below)
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Dameron, Bryant Mark. "Walk 14 Blocks." VCU Scholars Compass, 2007. http://scholarscompass.vcu.edu/etd/1431.
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Walk 14 Blocks is a document that describes my two-year investigation of simulation in everyday life. It describes how I examine both simulated places and the tools of simulation. I explain the key elements relating my work to simulation; experience, language, and the video monitor. I trace how I have utilized these elements in several works that led to my thesis exhibition titled Evidence.
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Balachandran, Neerajnayan. "Low power memory controller subsystem IP exploration using RTL power flow : An End-to-end power analysis and reduction Methodology." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280095.
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With FinFET based Application Specific Integrated Circuit (ASIC) designs delivering on the promises of scalability, performance, and power, the road ahead is bumpy with technical challenges in building efficient ASICs. Designers can no longer rely on the ‘auto-scaling’ power reduction that follows technology node scaling, in these times when 7nm presents itself as a ‘long-lived’ node. This leads to the need for early power analysis and reduction flows that are incorporated into the ASIC Intellectual Property (IP) design flow. This leads to a focus on power-efficient design in addition to being functionally efficient. Power inefficiency related hotspots are the leading causes of chip re-spins, and a guideline methodology to design blocks in a power-efficient manner leads to a power-efficient design of the Integrated Circuits (ICs). This alleviates the intensity of cooling requirements and the cost. The Common Memory controller is one of the leading consumers of power in the ASIC designs at Ericsson. This Thesis focusses on developing a power analysis and reduction flow for the common memory controller by connecting the verification environment of the block to low-level power analysis tools, using motivated test cases to collect power metrics, thereby leading to two main goals of the Thesis, characterization and optimization of the block for power. This work also includes an energy efficiency perspective through the Differential Energy Analysis technique, initiated by Qualcomm and Ansys, to improve the flow by improving the test cases that help uncover power inefficiencies/bugs and therefore optimize the block. The flow developed in the Thesis fulfills the goals of characterizing and optimizing the block. The characterization data is presented to provide an idea of the type of data that can be collected and useful for SoC architects and designers in planning for future designs. The characterization/profiling data collected from the blocks collectively contribute to the Electronic System-level power analysis that helps correlate the ASIC power estimate to silicon. The work also validates the flow by working on a specific sub-block, identifying possible power bugs, modifying the design and validating improved performance and thereby, validating the flow.Med FinFET-baserade applikationsspecifika integrerade kretsar (ASIC) -konstruktioner som ger löften om skalbarhet, prestanda och kraft är vägen framåt ojämn med tekniska utmaningar när det gäller att bygga effektiva ASIC: er. Formgivare kan inte längre lita på den "autoskalande" effektminskningen som följer teknisk nodskalning, i dessa tider då 7nm presenterar sig som en "långlivad" nod. Detta leder till behovet av tidig kraftanalys och reduktionsflöden som är integrerade i ASIC Intellectual Property (IP) designflöde. Detta leder till fokus på energieffektiv design förutom att det är funktionellt effektivt. Krafteffektivitetsrelaterade hotspots är de ledande orsakerna till respins av chip, och en riktlinjemetodik för att konstruera block på ett energieffektivt sätt leder till energieffektiv design av Integrated Circuits (ICs). Detta lindrar intensiteten hos kylbehovet och kostnaden. Common Memory-kontrollen är en av de ledande energikonsumenterna i ASIC-designen hos Ericsson. Denna avhandling fokuserar på att utveckla en effektanalys och reduktionsflöde för den gemensamma minneskontrollern genom att ansluta verifieringsmiljön för blocket till lågnivåeffektanalysverktyg, med hjälp av motiverade test caser för att samla effektmätvärden, vilket leder till två huvudmål för avhandlingen, karakterisering och optimering av blocket för kraft. Detta arbete inkluderar också energieffektivitetsperspektiv genom Differential Energy Analys-teknik, initierad av Qualcomm och Ansys, för att förbättra flödet genom att förbättra test cases som hjälper till att upptäcka effekteffektivitet / buggar och därför optimera blocket. Flödet som utvecklats i avhandlingen uppfyller målen att karakterisera och optimera blocket. Karaktäriseringsdata presenteras för att ge en uppfattning om vilken typ av data som kan samlas in och vara användbara för SoC-arkitekter och designers i planering för framtida mönster. Karaktäriserings/ profileringsdata som samlats in från blocken bidrar tillsammans till effektanalysen för elektronisk systemnivå som hjälper till att korrelera ASIC-effektberäkningen till kisel. Arbetet validerar också flödet genom att arbeta på ett specifikt underblock, identifiera möjliga effektbuggar, modifiera utforma och validera förbättrad prestanda och därmed validera flödet.
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Warner, Kelly. "Building Blocks Retreat Center." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1.
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In a perfect world, teamwork just exists. People function harmoniously with each other & their environment. Although we do not live in a perfect world, people and environments can always change and adapt to better their relationships. The Pumphouse was abandoned 41 years after the project was completed because it no longer met the needs and performed the functions that it needed to perform. It no longer serves the same purpose that it once did. And while acknowledging its past, it must also address its new functions and become a piece of beautiful, usable architecture once more. This space will encourage visitors to break down the established barriers from their home or workplace environments and experience true, lasting teamwork. Through chance encounters, shared spaces, and large group gathering areas, guests are encouraged to interact with each other in more than the expected ways. In breaking down barriers and formal establishments, guests embark upon a beautiful process intended to change the way they interact with each other. This process of discovery-symbolized by the elements within this space- encourages the visitors to grow, discover and become enchanted- and not disappointed- by what they find.
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Flink, Stephen Sperling. "Million Dollar Blocks." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/flink/FlinkS0509.pdf.
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Public housing in today's society is an accumulation of truths. These truths are a construct of institutions that are vastly different and sometimes conflicting but control and arrange life within the community. Public housing has transformed into a place of actual and perceived boundaries which constrict the control residents possess within the housing and its surroundings. The lack of control socially segregates, isolates, and stigmatizes residents as well as creates a dangerous environment. The residents' exclusion from outside communities prohibits them from functioning cohesively within society. With the objective of reducing crime rates, this thesis focuses on the physical environment's ability to transform the strict boundaries which separate public and private space within public housing. Blurring the influence of existing private spaces will give residents the ability to express territoriality within the public housing complex. A new order will be generated through localized interrelationships of private and public spaces. This environmental transformation will give residents among the public housing a sense of territoriality and the ability for self surveillance within their community. Inducing modes of habitation found outside of the public housing paradigm will return much needed control of space to the residents within the community.
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Fontes, Policarpo Óscar. "O processo de integração regional na SADC : desafios e limites para o aprofundamento da integração (2001-2010) /." São Paulo : [s.n.], 2012. http://hdl.handle.net/11449/134085.
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O Programa de Pós-Graduação em Relações Internacionais é instituído em parceria com a Unesp/Unicamp/PUC-SP, em projeto subsidiado pela CAPES, intitulado "Programa San Tiago Dantas"Orientador: Luis Ayerbe
Banca: Tullo Vigevani
Banca: Carlos Eduardo de Carvalho
Resumo: O presente trabalho é uma reflexão sobre o processo da integração regional na Comunidade de Desenvolvimento da África Austral (SADC). Aborda os desafios e limites para o aprofundamento da integração, no período que vai desde a reestruturação da SADC em 2001 até à dificuldade de estabelecimento da União Aduaneira em 2010. Durante esse período, o processo de integração regional progrediu lentamente sem que houvesse distribuição igual de ganhos entre os países pertencentes ao bloco. Argumenta-se que a múltipla filiação dos Estados da SADC tem sido obstáculo para o aprofundamento da integração regional. Analisa-se os principais desafios para o aprofundamento da integração e desenha perspectivas para o futuro.
Abstract: This work intends to reflect on the process of regional integration in Southern African Development Community (SADC). It discusses the challenges and limits to the deepening of integration in the period from the restructuring of SADC in 2001 to the difficulty of establishing the Customs Union in 2010. During this period, the regional integration process has moved slowly and there was no equal distribution of gains among the SADC member states. The argument hereof sugests as the main obstacles to further integration: the multiple membership of SADC member states to the various regional blocs.
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Hladišová, Barbora. "DŮM NA ÚPATÍ - MĚSTSKÝ DŮM V HISTORICKÉM CENTRU BRNA." Master's thesis, Vysoké učení technické v Brně. Fakulta architektury, 2013. http://www.nusl.cz/ntk/nusl-215943.
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The main objective of my diploma projest was to develop a comprehensive proposal for a town house at the intersection.This project detail design undeveloped parcel. The parcel stopping mainly apartment buildings and continues in the character of the street.
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Munksgaard, Daniel Carl. "Warblog without end: online anti-Islamic discourses as persuadables." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/715.
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This dissertation is a critical discourse analysis of how anti-Islamic rhetoric in prominent online forums is articulated within the context of popular discourses of multiculturalism and tolerance. According to Melanie McAlister, perceptions of Muslims within the United States are unique in comparison to other minority groups in that they are almost entirely mediated, whether it is the Iranian Revolution of 1979, the terrorist attacks of September 11th, or the various Muhammad cartoon controversies. While much work has been done analyzing how Islam and Muslims are mediated in popular film and television, very little attention has been given to how these perspectives are mediated through the Internet.
Using Erving Goffman's theory of performativity and Kristine Fitch's notion of persuadables, I examine how both prominent bloggers and pseudonymous commentators work in a "back stage" context to bring Islamophobic norms and premises within the sphere of acceptable opinions for the "front stage" of mainstream media discourses. In particular, I examine how these discourses have evolved over the past few years on three prominent weblogs: the anti-jihadist Little Green Footballs, the liberal-atheist advocacy blog One Good Move, and the popular news aggregate Fark. In light of increasing evidence that weblogs exert a high level of influence over popular media discourses disproportionate to their readership, these websites offer a glimpse "back stage" into how contemporary American discourses on Islam and Muslims are articulated across a broad array of political perspectives, particularly in relation to norms and premises regarding multiculturalism, tolerance, and freedom of expression.
While Islamophobic rhetoric has become firmly embedded within discourses of the American Right, each of the three sites examined show a steady integration of anti-Islamic perspectives within the American Left. Leftist anti-Islamic discourses are frequently articulated within the context of general anti-religious sentiment, misanthropy, and a belief that the values of "the Islamic world" are inherently incompatible with the liberal, democratic, and multicultural values of "the West." While by no means universal, these perspectives have become sufficiently common, recognizable, and sensible to be granted the status of persuadables within these particular web forums, which in turn helps to move them into the realm of popular American cultural persuadables.
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Bowens, Andrea Demetrius. "Synthesis and Characterization of Poly(siloxane imide) Block Copolymers and End-Functional Polyimides for Interphase Applications." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/29985.
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End-functional poly(ether amic acid)s and poly(siloxane imide) multiblock copolymers, comprised of 2,2'-Bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) / meta-phenylene diamine (MPDA) and hexafluoroisopropylidene-2-bis(phthalic acid anhydride) (6FDA) / meta-phenylene diamine (MPDA) polyimide segments, have been prepared and characterized to explore possibilities for controlling interface properties. Incorporation of polydimethylsiloxane (PDMS) components into polyimide backbone structures can yield advantageous properties such as low energy surfaces and low stress interfaces.
End-functional BPDA/MPDA poly(amic acid) salts and poly(siloxane amic acid) salts were prepared in methanolic or aqueous tripropylamine solutions. The polymeric salts formed stable water solutions (or dispersions) and imidized in less than 10 minutes at 260°C. The water solubility and rapid imidization times are ideal for on-line processing. Thus, these materials can be used as sizing and interface toughening agents for fiber reinforced composite manufacturing. Epoxy-polyimide networks prepared from the amine functionalized polyimide with DER 331 epoxy resin and diamino diphenylsulfone showed microphase separation (100-300 nm inclusions) by transmission electron microscopy. Slight toughening of the cured epoxy with 9 weight % imide was observed with the imide as the included phase. Epoxy bilayer films of polyimide (amine end-functional and commercial Ultem⠢) and poly(siloxane imide) multiblock copolymers were prepared to evaluate the polymer-matrix interphase region. Atomic force microscopy (AFM) analysis of the bilayer films showed diffusion at the interphase for the bilayers prepared with the polyimides and the BPADA/MPDA block copolymers containing polyimide continuous phases.
Poly(siloxane imide) multiblock copolymers comprised of 6FDA/MPDA polyimide structures are ideal candidates for controlling interfacial properties between silicon substrates layered with thin films for microelectronic applications. These high Tg materials offer an approach for obtaining reduced moisture absorption and low stress interfaces. Evaluation of the refractive indices of the block copolymer films showed a decrease with increasing siloxane content thus suggesting the possibility of lower dielectric constants. The polymer-metal interfacial properties were investigated for films cast on titanium and tantalum substrates. The results suggested a correlation between the surface hydroxyl concentration of the metal oxide layer with the interfacial properties of the cast poly(siloxane imide) block copolymer films. The surface hydroxyls were thought to hydrogen bond with the PDMS component of the block copolymer. Since the titanium substrate has a higher surface hydroxyl concentration than the tantalum, higher silicon concentrations were observed.
The melt imidized end-functional polyimides and poly(siloxane imide) block copolymers produced thermally stable materials with 5% weight loss temperatures well above 400°C. However, the block copolymers showed slightly lower 5% weight loss temperatures as a function of siloxane content with a significant increase in char formation. Correlation of the upper glass transition temperatures with the imide segment length was consistent with findings noted for other phase separated randomly segmented block copolymers.
Incorporating PDMS into the polyimide backbone structure has an effect on the bulk and surface properties. The bulk properties of the poly(siloxane imide) block copolymers were characterized using TEM. The morphologies were consistent with classical block copolymers. Surface properties of the block copolymer films as a function of PDMS content were investigated using angular dependent X-ray photoelectron spectroscopy at take-off angles of 15, 30, and 45°. Surface enrichment of PDMS content over that of the bulk was observed at all three sampling depths. Further evidence of this siloxane enrichment in the surface was demonstrated with water contact angle analyses. With as little as 5 weight % PDMS (Ph. D.
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Hughes, Gayle Hawkins. "Block scheduling in high school mathematics effect on Algebra II end-of-course grades and ACT assessment mathematics scores /." Lynchburg, Va. : Liberty University, 2008. http://digitalcommons.liberty.edu.
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Li, Xiaochen. "Hydrophilic [60]Fullerene End-Capped Polystyrene-Block-Poly (Ethylene Oxide) Copolymers: Synthesis and Self-Assembly in Solution." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1366664513.
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Buttler, David John. "Building blocks for composable web services." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180046/unrestricted/buttler%5Fdavid%5F200312%5Fphd.pdf.
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Meyer, Eric R. "Normal Fault Block or Giant Landslide? Baldy Block, Wasatch Range, Utah." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5550.
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Understanding the interplay between surficial and tectonic processes in the development of Utah's Wasatch Range is vital to evaluating geologic hazards along the Wasatch Front. Baldy is a large (6.125 km3) block of limestone and sandstone structurally overlying shale on the western flank of Mount Timpanogos. It has been mapped as a downdropped normal fault block of Permian units, but no other trace of such a fault exists along the range. The Baldy block structurally overlies the weak Manning Canyon shale, which has produced a regional geomorphology replete with faceted spurs, landslide scarps and deposits. Structural, bio- and litho-stratigrahic mapping of the block reveals breccia deposits, bed rotation and stratigraphic and structural relations to Mount Timpanogos consistent with a landslide interpretation. Structural reconstructions of the block and calculations of stream downcutting rates help constrain the timing and sequence of events of the block's emplacement. These results attest to the importance of surficial processes in the development of large-scale geologic structures, and demonstrate the ongoing danger of mass wasting to the communities of the Wasatch Front.
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Wang, Qijue. "Nanofibrils As The Basic Building Blocks Of Spider Silk." W&M ScholarWorks, 2020. https://scholarworks.wm.edu/etd/1593092048.
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Spider silk is a natural high-performance biopolymer with superior mechanical properties, resulting from its hierarchical structure. With protein nanofibrils observed in various spider and silkworm silks, the critical role of nanofibrils in achieving the silk's mechanical behavior has been widely suggested by both experimental observations and numerical simulations. However, a close review of available evidence of silk nanofibrils reveals many crucial aspects are still largely ambiguous or unknown. This further hinders the development of advanced silk-based materials. The simple structure of the ribbon-like recluse (Loxosceles) silk provides an ideal opportunity to investigate silk nanofibrils. By studying the surface and internal structure of this silk, we showed that it is entirely composed of nanofibrils. Since the recluse ribbons exhibit the outstanding mechanical properties typical of a good spider silk, we can conclude that the properties of recluse ribbons are already implemented at the level of an individual nanofibril. Furthermore, we took advantage of this system to study the protein makeup of pristine silk nanofibrils. Using both polarized FTIR and Raman spectroscopy, we presented the first-ever vibrational spectra of silk nanofibrils. We were able to identify the presence of different secondary structures, as well as their volumetric percentages and orientations. A detailed structure model of recluse silk was proposed based on our results. To relate the presence of nanofibrils to the natural silk spinning process, we investigated the self-assembly behavior of the native spider spidroin. Both individual and networks of long, thin silk nanofibrils were observed in the presence of shear force and a proper ion concentration. This unprecedented observation suggests the intrinsic tendency of native silk spidroin to form nanofibrils. In summary, through an extensive investigation of the organization, protein makeup, and formation of silk nanofibrils in various natural and in-vitro systems, we revealed the fundamental role of nanofibrils as the basic building blocks of natural spider silk. This will have wide-ranging implications on the understanding of the structure-property relations of spider silk and the development of silk-inspired high-performance materials.
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Alcaraz, Molly Marie. "Perspectives From SEI Teachers Instructing In Arizona's Four-Hour ELD Block." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/202757.
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In 2000, the passage of Proposition 203 in Arizona virtually replaced bilingual education with a Structured English Immersion (SEI ) program. In 2006, the State legislature passed House Bill (HB) 2064 which essentially segregated ELL students for four hours of the school day in an SEI classroom in which English Language Development (ELD) was taught. In 2008, the four-hour SEI block was mandated in public schools across Arizona.This study investigated the lived experiences of public school teachers teaching the four-hour SEI block, the relationship between what these teachers know about second language acquisition and the strategies they utilized, and what they identified as the strengths and weaknesses that resulted from the four-hour SEI block and its implementation.Nine K-12 SEI teachers from one school district in Southern Arizona participated in this study. Qualitative research methodologies were used to collect and analyze data.The results of this study showed that teachers' experiences and teaching strategies were diverse and greatly influenced by their classroom composition, professional development, interpretation of the laws surrounding the program, and directives given by administrators. Findings from this research also indicated that teachers identified substantially more concerns than advantages related to the four-hour SEI program. Specifically, teachers thought the SEI classroom provided a safe environment in which students could practice English. However, teachers were concerned about the negative social and academic repercussions experienced by ELLs as a result of the SEI program and also expressed their own professional concerns related to the four-hour model.
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Jeffery, Stephen Paul. "Metallodithiolate ligands as building blocks for molecular constructions." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1707.
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Richardson, James Kenneth. "The impact of block scheduling on student performance on the Virginia Standards of Learning End-of-Course assessments." W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1550154151.
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Huang, Jici. "Sorting by Block Moves." UNF Digital Commons, 2015. http://digitalcommons.unf.edu/etd/576.
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The research in this thesis is focused on the problem of Block Sorting, which has applications in Computational Biology and in Optical Character Recognition (OCR). A block in a permutation is a maximal sequence of consecutive elements that are also consecutive in the identity permutation. BLOCK SORTING is the process of transforming an arbitrary permutation to the identity permutation through a sequence of block moves. Given an arbitrary permutation π and an integer m, the Block Sorting Problem, or the problem of deciding whether the transformation can be accomplished in at most m block moves has been shown to be NP-hard. After being known to be 3-approximable for over a decade, block sorting has been researched extensively and now there are several 2-approximation algorithms for its solution. This work introduces new structures on a permutation, which are called runs and ordered pairs, and are used to develop two new approximation algorithms. Both the new algorithms are 2-approximation algorithms, yielding the approximation ratio equal to the current best. This work also includes an analysis of both the new algorithms showing they are 2-approximation algorithms.
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Palmer, Joseph M. "Real-Time Carrier Frequency Estimation Using Disjoint Pilot Symbol Blocks." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1780.
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Three new and efficient carrier frequency offset estimators are created for the case of disjoint pilot symbol blocks. The estimators are efficient in both a statistical sense and a computational sense. They are formulated to reduce computational cost for use in real-time applications, such as FPGA (field programmable gate array) devices. A reduced cost maximum likelihood (ML) frequency estimator is described. It is a generalization of the approximate ML estimator for a single block of pilot symbols. A number of recent ML estimation techniques are integrated with the purpose of reducing the computational cost while preserving estimation performance. The estimator incorporates multirate signal processing methods, FFT periodogram searches, and directed periodogram searches. The subsequent relationships between FFT lengths, resampling rates, and search iterations is established. The proposed estimator exhibits very good accuracy, operating range, and a low SNR threshold, and has low cost. A data-aided frequency estimator based on the measurement of phase increments, is also derived. It has extremely low cost, but a high SNR threshold. However, its formulation is such that a careful analysis of the range error problem may be performed. From this analysis certain conclusions are made about proper pilot symbol organization, and these conclusions are applicable to other frequency estimators. The third estimator is a generalization of the autocorrelation frequency estimation technique. The generalizations are needed to account for the spacings between the pilot blocks. A novel iterative approach, incorporating a Kalman filter, is used to improve operating range. It is shown that the autocorrelation frequency estimator exhibits good accuracy while maintaining a useful operating range. Real-time architectures are described for the ML and autocorrelation frequency estimators using disjoint pilot blocks. The computational cost and estimation performance of the proposed estimators are analyzed and it is shown that they give estimation performance near to theoretical limits, while preserving wide operating range. We see that the autocorrelation estimator is appropriate for small numbers of pilot symbols, while the ML estimator is appropriate for large numbers of pilot symbols. The new frequency estimators are the first to be derived (for the case of disjoint blocks of pilot symbols) such that computational cost is kept low, while still achieving high accuracy, a wide operating range, and low SNR thresholds.
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Rismal, Nina. "The ends of utopian thinking : Marx, Adorno, Bloch." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273982.
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My dissertation is concerned with utopian thinking in Critical Theory. It examines the changing conceptions of radically different social orders held by the associates of the Frankfurt School. Its aim is to investigate utopian thinking as a theoretical tool of a system of thought that is oriented towards social transformation. To bring about social transformation was the explicit objective of the Frankfurt School. And yet, as my dissertation demonstrates, some of the key member of the Frankfurt School discarded precisely this utopian tool. This rejection of utopian thinking is one of the central – but also one of the most problematic – aspects of Critical Theory. It goes back to the writings of Marx himself and culminates in the works of Theodor W. Adorno, specifically in his ‘Utopieverbot’ (prohibition of envisaging a utopian society). I argue that this Utopieverbot facilitated the disappearance of utopian thinking in Critical Theory, and furthermore, that it brought this system of thought to a standstill. In addition to the dissolution of utopian thinking my dissertation examines also its potential resuscitation. The foremost defender of utopian thinking I investigate is Ernst Bloch, a critical theorist overshadowed by Adorno himself. Countering Adorno, Bloch posited utopian thinking not only as a possible but also as a necessary theoretical tool of Critical Theory. I argue that Bloch’s ideas can be valuable in resolving the aporia of utopian thinking in Critical Theory. While important in its own right, this aporia is highly significant due to the enormous influence it exerted on the death of utopia in Western political thought, which can be seen as one of the key factors contributing to the escalating social, political and economic regressions of our contemporary era. Understanding the reasons behind the emergence of death of utopia, as well as its possible resolutions, thus present questions that urgently need to be addressed.
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Natarajan, Amla. "Hexahedral meshing of subject-specific anatomic structures using registered building blocks." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/717.
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To extend the use of computational techniques like finite element analysis to clinical settings, it would be beneficial to have the ability to generate a unique model for every subject quickly and efficiently. To this end, we previously developed two mapped meshing tools that utilized force and displacement control to map a template mesh to a subject-specific surface. This work is an extension of those methods; the objective of this study was to map a template block structure, common to multi-block meshing techniques, to a subject-specific surface. The rationale was that the blocks are considerably less refined and may be readily edited, thereby yielding a mesh of high quality in less time than mapping the mesh itself. In this paper, the versatility and robustness of the method was verified by processing four datasets. The method was found to be robust enough to cope with the variability of bony surface size, spatial position and geometry, producing building block structures that generated meshes comparable to those produced using building block structures that were created manually.
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Silva, Wilson José da. "Estudo experimental de ligações entre paredes de alvenaria estrutural de blocos cerâmicos sujeitas a ações verticais /." Ilha Solteira : [s.n.], 2003. http://hdl.handle.net/11449/90742.
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Orientador : Jefferson Sidney CamachoBanca: Luiz Roberto Prudêncio Júnior
Banca: José Antônio Matthiesen
Resumo: Com a finalidade de contribuir para um melhor entendimento sobre a distribuição das ações verticais entre paredes de edifícios de alvenaria estrutural de blocos cerâmicos, foi desenvolvido no presente trabalho uma série de ensaios que visam a análise da eficiência de dois tipos de ligações usuais entre paredes: as ligações de amarração direta (contrafiada) e as ligações com amarração indireta, através de grampos metálicos e graute. Para a consecução desses objetivos foram desenvolvidos diferentes programas experimentais, que contemplaram desde a caracterização das propriedades mecânicas dos componentes da alvenaria (blocos, argamassa, graute e aço) até a ensaios em corpos-de-prova (paredes "H") representativos das formas de ligações em estudo. Com o objetivo de se encontrar correlações com estes tipos de ligações, foram desenvolvidos, em paralelo, ensaios de cisalhamento em unidades (blocos) e ensaios em prismas especiais, aqui chamados prismas cavaletes. Por fim, os resultados experimentais obtidos no presente trabalho foram comparados com os resultados encontrados em modelos reduzidos, nas escalas 1:3 e 1:5, obtidos da revisão bibliográfica.
Abstract: With the intend to contribute for a better understanding about the vertical loads spreading between the ceramic blocks walls of a structural masonry building, it was developed within the present work a series of tests aiming the analysis of the efficiency of two usual walls connections, one directly connected (stretcher, bond) and the other indirectly connected throughout steel staples and grout. For the attainment of these objectives it was developed different experimental programs, which contemplated since the mechanical properties characterization of the masonry componentes (blocks, mortar, grout and steel) until the tests on the studying connections representative specimen ("H" walls). Aiming to find the correlations for these types of connections, it was also developed, in parallel, shearing tests on the units (blocks) and tests on special prisms, called here by "rack prisms". At the end, the experimental results obtained upon the present work were matched with the found small-scale results, on the (1:3) and (1:5) scales, obtained from the bibliographic revision.
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Aurangabadkar, Nilesh Kirti Kumar. "Simulations of analog circuit building blocks based on radiation and temperature-tolerant SIC JFET Technologies." Master's thesis, Mississippi State : Mississippi State University, 2003. http://library.msstate.edu/etd/show.asp?etd=etd-05162003-114102.
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Palmer, Joseph McRae. "Real-time carrier frequency estimation using disjoint pilot symbol blocks /." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd2786.pdf.
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Volodin, Aleksey. "Theoretical limits of block codes." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1174407313.
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Capocchi, Marina. "Flagler street: a strategy to revitalize and reconnect downtown Miami's city blocks." FIU Digital Commons, 2001. http://digitalcommons.fiu.edu/etd/2037.
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Reinbold, Robert S. "Factors Affecting Moisture Distribution in 290-Kilogram Stirred-Curd Cheddar Cheese Blocks." DigitalCommons@USU, 1991. https://digitalcommons.usu.edu/etd/5369.
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The purpose of this dissertation was to study factors affecting moisture distribution in 290-kilogram stirred-curd Cheddar cheese blocks cooled in stainless steel hoops. Uneven moisture distribution within blocks may create cheese with variable texture and flavor, which can be extremely costly to the producer. The effects of temperature, pH, and vacuum treatment on moisture distribution were investigated. Temperature, pH, moisture, and pressure profiles were presented. Also, comparisons were made between temperature profiles of 290- kilogram stirred-curd Cheddar cheese blocks cooled in stainless steel and in plywood hoops, as well as between temperature profiles of 66-kilogram Swiss cheese blocks cooled in cardboard and in plastic boxes.
Moisture transferred from high to low temperature in the cheese blocks. Moisture may have transferred in response to thermally induced curd moisture-holding capacity gradients in the cheese blocks. Moisture also may have transferred in the cheese blocks by a mechanism similar to thermo-osmosis of liquids in porous solids.
The cheese in the plywood or cardboard insulating materials cooled more uniformly than the cheese in the stainless steel or plastic containers. More uniform cooling of the cheese produced more uniform moisture distribution in the cheese blocks. Recommendations were made to help the cheesemaker produce cheese with even moisture distribution.
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Blockey, James Craig. "Feasibility in developing smart structures for use in wind turbine blades." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/blockey/BlockeyJ0808.pdf.
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Recently the use of wind as an alternative energy source has developed quickly. The length of the blades is a leading factor in the power output of a wind turbine and as a result, blade length has grown at a similar pace to the growth of the industry. The rapid expansion in use and size of wind turbines is not without its problems, though. As the industry has changed and grown, the overall design of the blades has remained relatively stagnant. This is evident in two primary areas, power control and health monitoring. Power control mechanisms are generally unchanged, utilizing either pitch control or active stall designs. While effective, these systems are neither efficient nor fast acting and can contribute to higher maintenance requirements. Current wind turbine blades also have no sensors built into them. The nacelle and tower utilize many sensors, but the blades themselves have none, leading to blades which are incapable of any real time health monitoring. The application of smart structures will enable the in situ monitoring of the blade and allow the blade to adapt to changing wind loadings Smart structures are those which apply an array of sensors to continuously monitor the state of the structure and are capable of using those sensors to appropriately react to achieve a desired state. This paper will examine the application of smart structures to the wind energy industry. It will be shown that a fiber optic, Fiber Bragg Grating sensor is the best type of sensor for wind energy. One of the main contributing factors is the capability of the sensors to multiplex, which means many sensors can be located along a single optical fiber and different types of sensors can be run on the same optical fiber. The blades will \'react\' to changing conditions through the use of an actuated Gurney style flap. The flap will be used to shed the wind loads from the blade in high wind scenarios. These systems working together will provide an effective and efficient method of advancing the design of the wind turbine blade to a level appropriate for the systems expected today and in the future.
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Bose, Gourav. "The 128-bit block cipher MARS." FIU Digital Commons, 2003. http://digitalcommons.fiu.edu/etd/1770.
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The purpose of the research is to investigate the emerging data security methodologies that will work with most suitable applications in the academic, industrial and commercial environments. Of several methodologies considered for Advanced Encryption Standard (AES), MARS (block cipher) developed by IBM, has been selected. Its design takes advantage of the powerful capabilities of modern computers to allow a much higher level of performance than can be obtained from less optimized algorithms such as Data Encryption Standards (DES). MARS is unique in combining virtually every design technique known to cryptographers in one algorithm.
The thesis presents the performance of 128-bit cipher flexibility, which is a scaled down version of the algorithm MARS. The cryptosystem used showed equally comparable performance in speed, flexibility and security, with that of the original algorithm. The algorithm is considered to be very secure and robust and is expected to be implemented for most of the applications.
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Muse, Frederic M. "Block Scheduling: From Possibility to Reality?" Digital Commons @ East Tennessee State University, 1997. https://dc.etsu.edu/etd/2954.
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This study examines teacher practices and student learning as perceived by teachers within public high schools that have implemented block scheduling. Comparisons are made between the possibilities advanced by block scheduling advocates and the actual results as interpreted from the data gathered. Comparisons are made between teaching and learning with the traditional schedule and the manner in which it takes place with block scheduling. Open-ended questionnaires were developed for use with voluntary participants who had worked with traditional scheduling and now taught with some form of block scheduling. Participants recorded observations based solely upon personal perceptions of experiences with students while teaching in both scheduling designs. Special demographic data were provided by each participant, numerically recorded, and analyzed for statistical differences. This study reports on the generalized trends of the data reported to this researcher. Data revealed that teachers have not adopted new teaching strategies, perceive that they are teaching less, and only the higher achievers benefit from the scheduling innovation. Students do not learn more with a longer class period. Block scheduling produced some unanticipated consequences such as teachers competing for students, reduced club participation, and principals gaining the ability to assign teachers a greater percentage of their preparations away from their major area of study. The importance of this study lies with the revealed effects of block scheduling not found in any other literature. The research effort gives voice to those persons who actually implemented the scheduling innovation. By using these first person accounts, this study discusses questions surrounding the block scheduling controversy that are not presented in current literature and sheds new light on those that are.
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Maurício, Rodrigo Menossi. "Estudo teórico e experimental das ligações diretas contra-fiadas entre paredes de blocos de concreto em escala real e reduzida 1:4 /." Ilha Solteira : [s.n.], 2005. http://hdl.handle.net/11449/90739.
Full textAbstract:
Orientador: Jefferson Sidney CamachoBanca: Rogério de Oliveira Rodrigues
Banca: Luiz Roberto Prudêncio Júnior
Resumo: O principal objetivo do trabalho foi desenvolver o estudo de ligações diretas entre paredes de blocos de concreto em escala real e reduzida 1A. Foram realizados ensaios de resistência à compressão axial e medidas as deformações em blocos, prismas e paredes nas duas escalas. Também foram montadas paredes em forma de H assentadas sobre bases de concreto armado. Estas foram construídas de 2 formas: na primeira, chamada de PRl, foram construídas 3 (três) unidades de modo que a parede central não possuísse apoio em sua base, com isso, todo o carregamento aplicado foi transferido para as abas. Na segunda forma, chamada PH2, foram montadas 3 (três) unidades, e ,nestas, a parede central ficou apoiada em sua base, dessa maneira, observou-se os efeitos de transferência de carga entre paredes, simulando uma estrutura real, onde geralmente todas as paredes da edificação são apoiadas em outras paredes ou em vigas baldrames. Na confecção dos corpos-de-prova, nas duas escalas em estudo, foi empregada uma argamassa industrializada usada comercialmente. O carregamento foi introduzido de forma centrada, e as deformações foram medidas através de relógios comparadores e de extensômetros elétricos. Para a análise dos resultados foram empregados testes estatísticos, validando estatisticamente as conclusões. Também foi empregada uma análise através de elementos finitos, simulando os ensaios experimentais realizados, comparando-se os resultados e readequando o modelo numérico. Os resultados obtidos permitiram uma avaliação da eficiência dos modelos numéricos empregados e os ajustes necessários nos mesmos, o entendimento da forma de transferência das ações verticais entre as paredes interligadas e as correlações entre as escalas estudadas.
Abstract: The main objective ofthis research was to develop a study of direct bond (stretcher bond) connections between walls of concrete blocks in real and 1:4 small-scale. In order to know the mechanical properties, it was accomplished shear and axial strength tests where it was also measured the strain in blocks, prisms and walls for both scales. It was executed walls in the "H" form supported by reinforced concrete base. These walls were done in two different ways, the first was called PRI, (with 3 specimens) it had no support in its central wall base, thus forcing that alI the load imposed to it was transferred to the lateral walIs throughout the connections. The second kind, which was called PH2, with also 3 specimens, was entirely support in its base. This was done in order to observe the load transference effects among walls simulating conventional structures, where all the walls are support over other walls or foundation beams. The specimens in both scales were made using industrialized mortar commercially used. The load was centralized imposed and strains were measurements by electrical displacement gages and strain gages. Statistical tests were used in the result analysis, statistically validating the conclusions. A finite element analysis was also used attempting to simulate the accomplished experimental tests, being this analytical model compared to the experimental results and then, by retrofitting the numerical analysis approaching their results. The obtained results allowed: an evaluation of the efficiency of the numeric models employed and the necessity of retrofitting the analysis; the comprehension in the way of transference of the vertical actions between the interlinked walls; and the correlations among the studied scales.
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Janarthanan, Arun. "Low power controller mapping by disabling thr embedded memory blocks in FPGAs." Cincinnati, Ohio University of Cincinnati, 2007. http://www.ohiolink.edu/etd/view.cgi?ucin1178109590.
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Thesis (M.S.)--University of Cincinnati, 2007.Title from electronic thesis title page (viewed July 9, 2007). Includes abstract. Keywords: FPGA; FSM Implementation; Sychronous Embedded Memory Block (SEMB) Includes bibliographical references.
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Olson, Jared K. "Ab Initio Search for Novel BxHy Building Blocks with Potential for Hydrogen Storage." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/844.
Full textAbstract:
On-board hydrogen storage presents a challenging barrier to the use of hydrogen as an energy source because the performance of current storage materials falls short of platform requirements. Because boron is one of the lightest chemical elements that can form strong covalent bonds with hydrogen, it provides an excellent opportunity to design new lightweight materials on the basis of novel boron hydride building blocks. Realizing this potential requires an understanding of the electronic structure, chemical bonding, and stability of neutral and anionic BxHy clusters with variable stoichiometry. While a large number of boron hydride compounds are known, there are still entire classes of yet unknown neutral and anionic BxHy clusters and molecules with various new x/y ratios which may be good candidates for hydrogen storage or as intermediates of borane de-hydrogenation. The primary aim of this dissertation was to search for neutral and anionic BxHy clusters that are thermochemically stable towards hydrogen release and to understand the chemical bonding in these novel clusters. These goals were accomplished by performing an unbiased search for neutral and anionic global minimum BxHy clusters using ab initio methods. In addition to finding a rich variety of new neutral and anionic BxHy (x = 3 – 6 and y = 4 – 7) clusters that could be building blocks for novel hydrogen-boron materials during the course of conducting this research, optical isomerism was discovered in select neutral and anionic boron-hydride clusters. Furthermore, the transition from planar to 3- dimensional geometries in global minimum B6Hx - clusters was discovered using ab initio techniques during this study. Chemical bonding analysis using the AdNDP method was performed for all global minimum structures and low-lying isomers. The chemical bonding pattern recovered by the AdNDP method in all cases is consistent with the geometric structure. The theoretical vertical detachment energies presented in this dissertation may help interpret future photoelectron spectroscopic studies of the anions presented here.
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Silva, Rodrigo Francisco da. "Estudo teórico-experimental da distribuição das ações verticais entre paredes de edifício de alvenaria estrutural cerâmica em escala reduzida /." Ilha Solteira : [s.n.], 2011. http://hdl.handle.net/11449/91455.
Full textAbstract:
Orientador: Jefferson Sidney CamachoBanca: Rogério de Oliveira Rodrigues
Banca: Marcio Roberto Silva Correa
Resumo: Esta pesquisa foi realizada com o intuito de se conhecer, através de análise teórico- experimental, a distribuição das ações verticais ao longo da altura das paredes de um edifício em alvenaria estrutural cerâmica não armada em escala reduzida. O edifício em questão é formado por quatro pavimentos, blocos cerâmicos e lajes maciças estando apoiado sobre sistema de vigas baldrames e estacas, sendo que as estacas estão sobre um pequeno radier. Após obtenção dos resultados experimentais necessários, foram feitas análises teóricas da distribuição das ações verticais, utilizando-se dos modelos de cálculos atualmente conhecidos e também através de um software comercial baseado no Método dos Elementos Finitos. Fez- se comparações com os resultados obtidos através dos ensaios experimentais com o intuito de verificar qual modelo de cálculo melhor representou o comportamento da alvenaria. A fim de avaliar a distribuição das ações verticais, o edifício foi ensaiado através de carregamentos uniformemente distribuídos - bandejas com água - sobre as lajes dos diferentes pavimentos, medindo assim, os valores de reações de apoio nos pontos instrumentados. Como principal conclusão, verificou-se que para cálculos manuais de distribuição de ações verticais as paredes não devem ser tratadas como isoladas, mesmo para edifícios de pequena altura, com poucos pavimentos, mas como pertencentes a determinado grupo, por causa da existência de interação entre elas.
Abstract: This research was carried out in order to know, through theoretical and experimental analysis, the distribution of vertical loads along the height of the walls of a building in unreinforced structural masonry with ceramic blocks in small scale. The building in question consists of four floors, ceramic blocks and slabs being supported on system foundation beams and piles, the piles are upon a small raft. After obtaining the necessary experimental results were made theoretical analysis of the vertical loads distribution, using the currently model calculations and also with a commercial software based on finite element method. Comparisons were made with the results obtained from experimental tests with in order to determine which calculation model best represented the behavior of masonry. In order to evaluate the distribution of vertical loads, the building was tested by imposing uniformly distributed loads - trays with water - upon the slabs of different floors, thus measuring the values of support reactions at points instrumented. The main conclusion, it was found that for manual calculations of the distribution of vertical loads the walls should not be treated as isolated, even for buildings of small height, with few floors, but as belonging to a particular group, because of interaction between them.
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Chacon, Rene, and Monika Ivantysynova. "An Investigation of the Impact of the Elastic Deformation of the End case/Housing on Axial Piston Machines Cylinder Block/Valve Plate Lubricating Interface." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199578.
Full textAbstract:
The cylinder block/valve plate interface is a critical design element of axial piston machines. In the past, extensive work has been done at Maha Fluid Power Research center to model this interface were a novel fluid structure thermal interaction model was developed which accounts for thermal and elasto-hydrodynamic effects and has been proven to give an accurate prediction of the fluid film thickness. This paper presents an in-depth investigation of the impact of the elastic deformation due to pressure and thermal loadings of the end case/housing on the performance of the cylinder block/valve plate interface. This research seeks to understand in a systematic manner the sensitivity of the cylinder block/valve plate interface to the structural design and material properties. A comparison between simulations results is done by utilizing different end case designs and material compositions, both in the valveplate and end case solids.
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Galasso, Alison Marie. "Parametric Exploration of Block Shear Formulations." Digital WPI, 2011. https://digitalcommons.wpi.edu/etd-theses/282.
Full textAbstract:
Block shear is a mode of failure in which a steel member fails in tension along one plane and shear on a perpendicular plane along the fasteners. The design process for block shear has been at the center of debate since it first appeared in the 1978 AISC Specification and has evolved over the years. This thesis investigated the block shear design equations as they have progressively changed from the 1978 provisions for Allowable Stress Design (ASD) to the 2005 provisions for Load and Resistance Factor Design (LRFD). Block shear strength capacities were calculated for multiple designs involving coped beams, angles, and structural tees. These analytical values were compared to physical test findings available in the literature. The results of this study compare the different strength predictions to one another, as well as benchmark the AISC provisions to actual physical testing strengths. The comparisons were also used to determine whether the ASD and LRFD specifications follow similar trends. Good agreement between the predicted capacities and the results from physical testing was observed for a majority of the geometries investigated. However, capacity predictions based on increasing the number of rows of bolts for a coped beam and changing the length of the outstanding leg for an angle or tee connection were found to disagree with the test results. A finite element study was also completed to further explore the influence of changing the length of the outstanding leg of tee connections because these geometries showed considerable disagreement between the calculated capacities and the test data.
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Bhagat, Nitin. "A block structured adaptive solution to the shallow water equations." Master's thesis, Mississippi State : Mississippi State University, 2004. http://library.msstate.edu/etd/show.asp?etd=etd-06252004-135938.
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Van, Schoor Christiaan de Wet. "Building blocks for supply chain management a study of inventory modelling /." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-10192006-125907.
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Hayes, Melissa M. "The building blocks of Atlanta racial residential segregation and neighborhood inequity /." unrestricted, 2006. http://etd.gsu.edu/theses/available/etd-07272006-111411/.
Full textAbstract:
Thesis (M.A.)--Georgia State University, 2006.Title from title screen. Robert Adelman, committee chair; Charles Jaret, Dawn Baunach, committee members. Electronic text (92 p. : ill., col. maps) : digital, PDF file. Description based on contents viewed July 25, 2007. Includes bibliographical references (p. 86-92).
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Cooper, Kevin L. "Liquid crystalline multi-block copolymers." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-05222007-091335/.
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Andolfato, Rodrigo Piernas. "Desenvolvimento das técnicas de produção de blocos de concreto para alvenaria estrutural na escala (1:4) /." Ilha Solteira : [s.n], 2002. http://hdl.handle.net/11449/91498.
Full textAbstract:
Orientador: Jefferson Sidney CamachoBanca: Marcio Antonio Ramalho
Banca: José Antonio Matthiesen
Resumo: O presente trabalho teve como objetivo principal o estudo e o desenvolvimento das técnicas de produção de blocos de concreto para alvenaria estrutural na escala reduzida de (1:4). Os blocos em escala reduzida foram produzidos para apresentarem o mesmo comportamento em termos de resistência à compressão e deformabilidade que os seus pares em escala real. Para as duas escalas em estudo, (1:1) e (1:4), foram produzidos blocos com quatro traços diferentes entre si. Além dos blocos, também foram construídos e ensaiados à compressão prismas de três fiadas, nas duas escalas, de modo a determinar as correlações entre as resistências e deformações nas duas escalas. Para a consecução do objetivo acima, foram desenvolvidos ensaios de compressão axial em unidades e prismas de três blocos, nas escalas (1:1) e (1:4). Os parâmetros observados, medidos e comparados foram as resistências à compressão, os módulos de deformação, as curvas tensão-deformação e as formas de ruptura apresentadas pelos corpos-de-prova. Como resultado final, chegou-se a uma série de procedimentos que, quando observados, permitem a reprodução de blocos de concreto para alvenaria estrutural na escala (1:4), mantendo praticamente as mesmas características de resistência à compressão e deformabilidade, tanto para as unidades quanto para os prismas estudados.
Abstract: The present work had as main objective to study and the development of production techniques of the small-scale concrete blocks for structural masonry in the (1:4) reduced scale. The blocks in the small-scale were produced to present the same behavior in terms of compression strength and deformability as their equivalents in the full scale. For both studied scales, (1:1) and (1:4), blocks were produced in four different mixtures. Additionally to the blocks, it was built and tested three courses prisms, in both scales, in the way to establish the correlations between the compression strength and the deformations. To match the above objective, axial compression tests were developed in units and prisms, on the scales (1:1) and (1:4). The observed, measured and compared parameters were the compression strength, the strains, the stress-strain curves and the rupture forms presented by the specimens. As a final result, it was established a series of procedures that, when observed, allows the reproduction of the concrete blocks for structural masonry in the scale (1:4), keeping practically the same characteristics of compression strength and deformability, either for the units or for the prisms.
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Oliveira, Adriano Marim de. "Obtenção de nanopartículas sensíveis a temperatura e pH a partir de copolímeros em bloco constituídos de poli(hidroxibutirato-co-hidroxivalerato) e poli(n-isopropilacrilamida-co-ácido acrílico) sintetizado via RAFT visando aplicação em enc." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/97/97133/tde-20082013-163038/.
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Recentemente, utilizando a técnica de auto-agregação (\"self-assembly\") foi possível visualizar a possibilidade de se obterem estruturas de tamanhos nanométricos de maneira rápida, em poucas etapas sintéticas e por meio de simples atrações físicas entre as macrocadeias, simulando as interações dos peptídeos nas proteínas. A principal característica desta técnica baseia-se na estrutura química dos polímeros sintéticos que permite o processo de autoagregação somente com interações físicas entre as macrocadeias (sem ligações covalentes). Por meio desta técnica é possível obter, com eficiência e rapidez, estruturas nanométricas que seriam de difícil obtenção por técnicas convencionais.O objetivo principal desta tese foi estudar uma rota química para a síntese de copolímeros em bloco anfifílicos e a preparação de nanopartículas sensíveis à variação de temperatura e pH, pelo método de auto-agregação. Para isso, copolímeros em bloco anfifílicos foram sintetizados utilizando como segmento hidrofóbico o Poli(hidroxibutirato-co-hidroxivalerato) (PHBHV) e como segmento hidrofílico foram utilizados a Poli(N-isopropilacrilamida) (PNIPAAm) e Poli(N-isopropilacrilamida-co-ácido acrílico) (PNIPAAmAA). Estes polímeros chamados \"inteligentes\" foram sintetizados pelo novo mecanismo de polimerização radicalar controlada, por transferência de cadeia, via fragmentação e adição reversíveis (RAFT). Essas nanopartículas termo-pH-sensíveis foram empregadas nos estudos de liberação controlada de um ativo modelo, o acetato de dexametasona, sob condições controladas de temperatura e pH. Com os resultados obtidos nesta tese foi possível identificar uma rota química de síntese de copolímeros em bloco anfifílicos sensíveis a temperatura e pH, utilizando-se de reações de acoplamento entre um polímero biodegradável, obtido de fontes renováveis, e polímeros \"inteligentes\". Foi possível demonstrar também, a viabilidade de utilização destes copolímeros anfifílicos na preparação de nanopartículas pela técnica de auto-agregação, o emprego deste sistema na encapsulação e a liberação controlada de um ativo modelo em função de variações de temperatura e pH.Recently, the self-assembly technique provided an efficient and rapid pathway for obtaining nanometers structures in a nanometer scale using few steps of reactions and by means of simple physical attractions among macro chains, simulating the folding of peptide segments in proteins. The main characteristic of this technique is based on the chemical structure of the synthetic polymers which allow the self degradation process only with physical interactions between the macro chains (without covalent bonds). By the utilization of this technique is possible to obtain, easily and efficiently, nanometers structures, which would be difficult to be obtained by conventional techniques. The aim of this work was to study a chemical route for designing amphiphilic block copolymers and nanoparticles that exhibit thermo and pH responsive by means of self-assembly method. For this purpose, amphiphilic block copolymers were synthesized using as hydrophobic segment Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) and as hydrophilic segments, Poly(N-isopropylacrylamide) (PNIPAAm) and Poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAAmAA). The hydrophilic polymers, called \"smart\" polymers were synthesized by a new mechanism of controlled radical polymerization, the reversible addition-fragmentation chain transfer (RAFT). These nanoparticles sensitive to temperature and pH were utilized in a drug delivery system of a model drug, the Dexametasone acetate (DexAc) under controlled environment of temperature and pH. The results allowed identifying a chemical route for the synthesis of stimuli-responsive amphiphilic block copolymers by means of coupling reactions of a biodegradable polymer obtained from renewable resources with smart polymers. It was also possible to demonstrate the possibility of utilization of these amphiphilic copolymers in the preparation of nanoparticles by self-assembly technique as well as the utilization of this system in the encapsulation and in the drug delivery of a model drug with variation of temperature and pH.