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Towards dense linear algebra for hybrid GPU accelerated manycore systems

Baboulin, Marc; Dongarra, Jack; Tomov, Stanimire
Fonte: Centro de Matemática da Universidade de Coimbra Publicador: Centro de Matemática da Universidade de Coimbra
Tipo: Pré-impressão
ENG
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If multicore is a disruptive technology, try to imagine hybrid multicore systems enhanced with accelerators! This is happening today as accelerators, in particular Graphical Processing Units (GPUs), are steadily making their way into the high performance computing (HPC) world. We highlight the trends leading to the idea of hybrid manycore/GPU systems, and we present a set of techniques that can be used to e ciently program them. The presentation is in the context of Dense Linear Algebra (DLA), a major building block for many scienti c computing applications. We motivate the need for new algorithms that would split the computation in a way that would fully exploit the power that each of the hybrid components o ers. As the area of hybrid multicore/GPU computing is still in its infancy, we also argue for its importance in view of what future architectures may look like. We therefore envision the need for a DLA library similar to LAPACK but for hybrid manycore/GPU systems. We illustrate the main ideas with an LUfactorization algorithm where particular techniques are used to reduce the amount of pivoting, resulting in an algorithm achieving up to 388 GFlop/s for single and up to 99:4 GFlop/s for double precision factorization on a hybrid Intel Xeon (2x4 cores @ 2.33 GHz) { NVIDIA GeForce GTX 280 (240 cores @ 1.30 GHz) system.

Occurrence of TRGV-BJ hybrid gene in SV40-transformed fibroblast cell lines

D`ARCE, L. P. G.; BASSI, C. L.; FACHIN, A. L.; PASSOS, G. A. S.; SAKAMOTO-HOJO, E. T.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
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Illegitimate V(D)J-recombination in lymphoid malignancies involves rearrangements in immunoglobulin or T-cell receptor genes, and these rearrangements may play a role in oncogenic events. High frequencies of TRGV-BJ hybrid gene (rearrangement between the TRB and TRG loci at 7q35 and 7p14-15, respectively) have been detected in lymphocytes from patients with ataxia telangiectasia (AT), and also in patients with lymphoid malignancies. Although the TRGV-BJ gene has been described only in T-lymphocytes, we previously detected the presence of TRGV-BJ hybrid gene in the genomic DNA extracted from SV40-transformed AT5BIVA fibroblasts from an AT patient. Aiming to determine whether the AT phenotype or the SV40 transformation could be responsible for the production of the hybrid gene by illegitimate V(D)J-recombination, DNA samples were extracted from primary and SV40-transformed (normal and AT) cell lines, following Nested-PCR with TRGV- and TRBJ-specific primers. The hybrid gene was only detected in SV40-transformed fibroblasts (AT-5BIVA and MRC-5). Sequence alignment of the cloned PCR products using the BLAST program confirmed that the fragments corresponded to the TRGV-BJ hybrid gene. The present results indicate that the rearrangement can be produced in nonlymphoid cells...

Elementos finitos híbridos e híbrido-mistos de tensão com enriquecimento nodal; Stress hybrid and hybrid-mixed finite elements with nodal enrichment

Góis, Wesley
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/05/2009 PT
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Neste trabalho, a técnica de enriquecimento da partição da unidade é estendida e adaptada para duas formulações não-convencionais para a elasticidade plana: a formulação híbrida de tensão (FHT) e a formulação híbrido-mista de tensão (FHMT). Estas formulações são ditas não-convencionais, pois não recorrem a princípios variacionais clássicos. Elementos finitos triangulares e quadrilaterais com enriquecimento nodal são desenvolvidos para avaliação da forma discreta das duas formulações estudadas. Na FHMT, três campos são aproximados de forma independente: tensões e deslocamentos no domínio e deslocamentos no contorno. O conceito de partição da unidade é então utilizado para garantir continuidade de cada um dos campos envolvidos na FHMT e realizar o procedimento de enriquecimento nodal. Funções polinomiais são utilizadas para enriquecer cada uma das aproximações dos campos da FHMT. A sensibilidade das respostas em relação a redes distorcidas é avaliada. Além disso, abordam-se aspectos relativos à convergência e estabilidade da solução numérica. Especificamente para a FHT, dois campos são independentemente aproximados: tensões no domínio e deslocamentos na fronteira estática. As aproximações das tensões...

Caracterização da distribuição da miosina rápida, lenta e híbrida na musculatura da mastigação; Characterization of fast, slow and hybrid fibers in masticatory muscles

Guimarães, Thatiana Bastos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/10/2009 PT
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Introdução: Os músculos da mastigação masseter, temporal, pterigóideo medial e pterigóideo lateral são componentes essenciais do sistema estomatognático. A mastigação decorre da movimentação destes músculos. Além da função fisiológica, os músculos da mastigação estão envolvidos na disfunção temporomandibular (DTM) que é importante causa de dor, sons articulares e função mandibular irregular ou limitada. As DTM representam a maior causa de dor não dental na região orofacial, sendo a causa muscular a mais prevalente. O conhecimento detalhado da composição estrutural e funcional dos músculos da mastigação é fundamental para a compreensão dos mecanismos da DTM muscular. Objetivos: Analisar a distribuição da expressão das isoformas de miosina (rápida e lenta) e, a quantidade de fibras híbridas nos músculos temporal e masseter em material de autópsia da 1a a 9a décadas. Casuística e métodos: Foram estudadas 37 amostras dos músculos temporal e masseter (20 amostras do sexo masculino e 17 do sexo feminino) de autópsias do Serviço de Verificação de Óbitos de São Paulo com intervalo pós-mortem de até 18 horas, de ambos os gêneros e com idades divididas por décadas (1a a 9a décadas). Resultados: Não houve diferença estatística significante na porcentagem de fibras rápidas...

Partículas e filmes híbridos de polímeros e compostos de amônio quaternário com atividade antimicrobiana; Particles and films hybrid of polymers and quaternary ammonium compounds with antimicrobial activity

Melo, Letícia Dias de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/02/2011 PT
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Partículas e filmes híbridos de polímeros e compostos de amônio quaternário (CAQ) foram caracterizados quanto a propriedades físicas e atividade contra cepas de Pseudomonas aeruginosa ATCC 27853 e Staphylococcus aureus ATCC 25923. Partículas híbridas foram obtidas a partir de fragmentos de bicamada (BF) de brometo de dioctadecildimetilamônio (DODAB), adicionados consecutivamente de soluções de carboximetilcelulose (CMC) e cloreto de poli (dialildimetilamônio) (PDDA) e, a seguir, caracterizadas por espalhamento de luz dinâmico para determinação de distribuições de tamanho, diâmetro médio (Dz) e potencial-zeta (ζ). Filmes híbridos foram obtidos por revestimento rotacional de lamínulas de vidro a partir de uma solução clorofórmica de poli (metil metacrilato) (PMMA) e CAQ onde [PMMA] = 10 mg/mL e [CAQs] = 0,03 4 mM de DODAB, brometo de cetiltrimetilamônio (CTAB) ou brometo de tetrapropilamônio (TPAB). Molhabilidade dos filmes e difusibilidade dos CAQs nos filmes imersos em água foram avaliadas por determinação de ângulo de contato e de tensão superficial na interface ar-água, respectivamente. Atividade antimicrobiana foi avaliada por plaqueamento e contagem de viáveis, tanto para os filmes quanto para as partículas. Para os filmes...

Produtos híbridos: um estudo multicasos sobre sua utilização em momentos de transição tecnológica; Hybrid Products: a multi case study for their use in technological transition moments

Gatti Junior, Wilian
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/06/2015 PT
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Esta pesquisa investiga os fatores direcionadores para a utilização de produtos híbridos em contextos de transição tecnológica. É considerado um produto híbrido aquele que reúne, em sua arquitetura, muitos dos componentes ou subsistemas centrais pertencentes a duas gerações tecnológicas distintas para desempenhar uma mesma função o que caracteriza o produto como um híbrido intergerações. Uma destas tecnologias é a tecnologia estabelecida (a antiga) e a outra é a inovação (a nova tecnologia) lançada e/ou em teste no mercado. Apesar de o emprego de produtos híbridos não ser recente, este trabalho objetiva analisar e contribuir com a discussão sobre seus antecedentes, isto é, pesquisar os principais elementos e condicionantes do emprego de produtos híbridos, investigação bastante incipiente na literatura. Com base na revisão das literaturas de estratégias de inovação, desenvolvimento de novos produtos, cadeia de suprimentos e também de competências organizacionais, o trabalho levanta quatro proposições acerca das condições de maior propensão ao emprego da estratégia de produto híbrido. O estudo de caso foi escolhido como abordagem de pesquisa, realizado de modo retrospectivo (histórico) com a utilização de casos múltiplos descritos em profundidade...

Influência do processo de cura das películas híbridas no desempenho de revestimentos obtidos por pintura epoxídica; Influence of the curing process of the hybrid films on the performance of coatings obtained by epoxy painting

Kunst, Sandra Raquel; Korb, Matias de Angelis; Menezes, Tiago Lemos; Tessaro, Giovanni; Oliveira, Cláudia Trindade; Malfatti, Célia de Fraga
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
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O pré-tratamento com películas híbridas obtidas pelo processo sol-gel, a partir de precursores alcoóxidos específicos, tem sido uma alternativa, ambientalmente correta, proposta para a proteção contra corrosão de diferentes substratos metálicos, incluindo o aço galvanizado. Nas películas híbridas, os componentes inorgânicos contribuem para o aumento da resistência à corrosão e adesão ao substrato metálico, enquanto os componentes orgânicos aumentam a densidade, flexibilidade e compatibilidade funcional com sistemas orgânicos, como, por exemplo, a pintura. A adição de inibidores de corrosão, ou outros compostos, à película híbrida pode modificar as propriedades de barreira, melhorando a resistência à corrosão. No presente trabalho, o aço galvanizado foi pré-tratado com uma película híbrida obtida a partir de um sol constituído pelos precursores alcoóxidos 3-(trimetoxisililpropil) metacrilato (TMSPMA) e tetraetoxisilano (TEOS), com adição de nitrato de cério, na concentração de 0,01 M. Os filmes híbridos foram submetidos a diferentes mecanismos de cura: secagem ao ar, cura térmica e cura por radiação ultravioleta. Os sistemas obtidos foram caracterizados quanto à aderência, morfologia e comportamento eletroquímico. Além disso...

Analysing hybrid pension plans : an illustration

Adeboye, Oluwafeyikemi Adebunmi
Fonte: Instituto Superior de Economia e Gestão Publicador: Instituto Superior de Economia e Gestão
Tipo: Dissertação de Mestrado
Publicado em //2014 ENG
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Mestrado em Ciências Actuariais; Nesta dissertação apresentamos uma ilustração dos alguns planos de pensões híbridos, em cinco países, que em nossa opinião podem ser tomados como referência no que respeita à evolução desse tipo de fundos. O objetivo foi tirar ilações sobre as razões do aumento do recurso aos planos de pensões híbridos, em alternativa aos planos de benefício definido ou de contribuição definida. Se bem que os planos híbridos não sejam comuns, nos últimos tempos, devido ao esforço para atenuar os riscos nos planos tradicionais, têm por vezes vindo a ser considerados uma opção menos arriscada, devido às suas características. Na ilustração considerada nesta dissertação, temos um participante tipo que acabou de ser admitido no fundo de pensões e analisamos três modelos de planos híbridos, que comparamos com os planos de benefício definido e contribuição definida. O propósito é determinar, do ponto de vista do empregador e do ponto de vista do participante, quais os impactes de futuros choques nas taxas de juros, nas atualizações salariais anuais e na idade de reforma. As ilustrações permitiram observar que os planos de pensões híbridos, de facto, oferecem melhores perspetivas...

Resistance modality of hybrid sorghum to sorghum midge.

WAQUIL, J.M.; TEETES, G.L.
Fonte: In: BIENNIAL GRAIN SORGHUM RESEARCH AND UTILIZATION CONFERENCE, 14., 1985, Texas. [Proceedings]. Lubbock: Grain Sorghum Producers Association, 1985. p. 69. Publicador: In: BIENNIAL GRAIN SORGHUM RESEARCH AND UTILIZATION CONFERENCE, 14., 1985, Texas. [Proceedings]. Lubbock: Grain Sorghum Producers Association, 1985. p. 69.
Tipo: Resumo em anais de congresso (ALICE)
EN
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Using the sorghum midge, Contarinia sorghicola (Coq.), resistant hy-brid ATx2755 X Tx2767 and the susceptible hybrid ATx2752 X Tx430 several aspects of the resistance were examined under field conditions from 1982 to 1984 at College Station, Texas. Based on the number of oviposition adult midges trapped per flowering panicle, about 1/3 more female midges visited flowering panicles of the susceptible hybrid than the resistant. In addition, comparing the number of eggs laid by 20 caged females, it was shown that 4-5 times more eggs were laid in spikelets of the susceptible hybrid than spikelets of the resistant hybrid.Although and equivalent proportion of eggs was laid during and before anthesis in spikelets of both hybrids, a significantly lower proportion of eggs was laid in flowers of the resistant hybrid after anthesis. There aspects of adult ovipositional behavior were determined. About 25% more females were trapped on flowering panicles which had not been previously midge infested compared to when panicles had already been infested. Sorghum midge females searched the flowers of the resistant hybrid more rapidly than they did the susceptible; however, the time used attempting to oviposite waslonger. Also, the frequency of ovipositional sucess was much lower...

A Performance Evaluation of Optimal Hybrid Cache Coherency Protocols

Veenstra, Jack E. ; Fowler, Robert J.
Fonte: University of Rochester. Computer Science Department. Publicador: University of Rochester. Computer Science Department.
Tipo: Relatório
ENG
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The caches within a multiprocessor typically use either a write-invalidate protocol or a write-update protocol to maintain consistency. The recently introduced MIPS R4000 processor allows operating system software to select, on a per-page basis, which multiprocessor cache coherence protocol (write-invalidate versus write-update) the hardware will use. The availability of the R4000 and the prospect of even more flexible hardware motivated us to examine the potential performance advantages of allowing user-level control over the choice of coherence protocol on a per-page basis and to ask whether more powerful hybrid protocols provide substantially more benefit. We examine the potential benefits of three classes of hybrid protocols: (1) hybrid protocols that choose statically, at the beginning of the program, between write-invalidate (WI) or write-update (WU) on a per-page basis, (2) hybrid protocols that choose statically between WI or WU for each cache block, and (3) dynamic hybrid protocols that can choose between WI or WU at each write. In order to determine how much potential benefit could be obtained by each of these protocol classes, we used trace-driven simulations to evaluate the optimal off-line protocol for each class. We found that the use of a hybrid protocol can substantially reduce the cost of memory references for most of the programs studied. A few programs can also realize large additional benefits from a per-block static hybrid protocol compared to a per-page static hybrid protocol. None of the programs...

The Development of a Hybrid Optimization Algorithm for the Evaluation and Optimization of the Asynchronous Pulse Unit

Inclan, Eric
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
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The effectiveness of an optimization algorithm can be reduced to its ability to navigate an objective function’s topology. Hybrid optimization algorithms combine various optimization algorithms using a single meta-heuristic so that the hybrid algorithm is more robust, computationally efficient, and/or accurate than the individual algorithms it is made of. This thesis proposes a novel meta-heuristic that uses search vectors to select the constituent algorithm that is appropriate for a given objective function. The hybrid is shown to perform competitively against several existing hybrid and non-hybrid optimization algorithms over a set of three hundred test cases. This thesis also proposes a general framework for evaluating the effectiveness of hybrid optimization algorithms. Finally, this thesis presents an improved Method of Characteristics Code with novel boundary conditions, which better characterizes pipelines than previous codes. This code is coupled with the hybrid optimization algorithm in order to optimize the operation of real-world piston pumps.

Hybrid walking therapy with fatigue management for spinal cord injured individuals

Ama Espinosa, Antonio José del
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado
ENG
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In paraplegic individuals with upper motor neuron lesions the descending path for signals from central nervous system to the muscles are lost or diminished. Motor neuroprosthesis based on electrical stimulation can be applied to induce restoration of motor function in paraplegic patients. Furthermore, electrical stimulation of such motor neuroprosthesis can be more efficiently managed and delivered if combined with powered exoskeletons that compensate the limited force in the stimulated muscles and bring additional support to the human body. Such hybrid overground gait therapy is likely to be more efficient to retrain the spinal cord in incomplete injuries than conventional, robotic or neuroprosthetic approaches. However, the control of bilateral joints is difficult due to the complexity, non-linearity and time-variance of the system involved. Also, the effects of muscle fatigue and spasticity in the stimulated muscles complicate the control task. Furthermore, a compliant joint actuation is required to allow for a cooperative control approach that is compatible with the assist-as-needed rehabilitation paradigm. These were direct motivations for this research. The overall aim was to generate the necessary knowledge to design a novel hybrid walking therapy with fatigue management for incomplete spinal cord injured subjects. Research activities were conducted towards the establishment of the required methods and (hardware and software) systems that required to proof the concept with a pilot clinical evaluation. Speciffically...

Hybrid swarms: catalysts for multiple evolutionary events in Senecio in the British Isles

Lowe, A.J.; Abbott, R.J.
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
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Background: Introgressive hybridisation is an evolutionary catalyst producing novel variants able to explore new ecological niches and evolve as new hybrid taxa. However, the role of ‘hybrid swarms’ – highly variable populations produced following interspecific hybridisation – in generating this evolutionary novelty has been poorly studied. Aims: We examine the alternative origins of tetraploid hybrid derivatives of Senecio vulgaris and S. squalidus, via local polytopic formation or long-distance dispersal from a single perennial hybrid swarm around Cork, Ireland. Methods: Morphometric, isozyme and chloroplast DNA analysis. Results: The Cork hybrid swarm and UK hybrid swarms exhibited a broad range of morphological variation and contained individuals similar to the stable tetraploid hybrid derivatives; S. eboracensis and S. vulgaris var. hibernicus. Chloroplast DNA analysis shows that S. eboracensis did not evolve from the Cork hybrid swarm. However, UK S. vulgaris var. hibernicus populations exhibit a broad range of variation for both chloroplast and isozyme markers, but were not distinguishable from Cork material. Conclusions: Our study confirms that S. eboracensis did not evolve from the Cork hybrid swarm, and while our analyses could not demonstrate this conclusively for S. vulgaris var. hibernicus the ease with which hybrid swarms have been generated in the past makes a polytopic origin for S. vulgaris var. hibernicus the most likely scenario.; Andrew J. Lowe...

Method to obtain hybrid rapid tools with elementary component assembly

RIVETTE, Mickaël; MOGNOL, Pascal; HASCOET, Jean-Yves
Fonte: emerald Publicador: emerald
EN
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M. Rivette, P. Mognol, J.Y. Hascoet, (2013) "Method to obtain hybrid rapid tools with elementary component assembly", Rapid Prototyping Journal, Vol. 19 Iss: 2, pp.77 - 87 DOI : 10.1108/13552541311302923; Purpose – The purpose of this paper is to propose a method to obtain hybrid rapid tools with elementary component assembly. Design/methodology/approach – The authors' method proposes a functional representational model, starting with the product features, analyzed from three points of view: a feasibility analysis; a manufacturing analysis; and an assembly and synthesis analysis. This method, based on CAD STEP AP-224 data, makes it possible to obtain an exhaustive list of solutions for the module. The work is illustrated with an industrial example. To construct the Assembly Identity Card (AIC) and test the various parameters that influence the quality of the injected parts, a hybrid injection mold has been produced. The methodology associated with the use of this AIC uses a “representation graph”, which makes it possible to propose a set of valid solutions for assembling the various tooling modules. This method is validated by industrial example. Findings – The product part is decomposed into a multi-component prototype (MCP)...

Técnicas de razonamiento automático para lógicas híbridas; Automated reasoning techniques for hybrid logics

Gorín, Daniel Alejandro
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2009 SPA
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Las "lógicas híbridas" extienden a las lógicas modales tradicionales con el poder de describir y razonar sobre cuestiones de identidad, lo cual es clave para muchas aplicaciones. Aunque lógicas modales que hoy llamaríamos "híbridas" pueden rastrearse hasta cuatro décadas atrás, su estudio sistem ático data de fines de la década del '90. Parte de su interés proviene de que llenan un hueco de expresividad importante de las lógicas modales tradicionales. Uno de los temas de esta tesis es el problema de la satisfacibilidad para la lógica híbrida más conocida, denominada H(@;!), y algunas de sus sublógicas. El de la satisfacibilidad es el problema fundamental en razonamiento automático. En el caso de las lógicas híbridas, éste se ha estudiado fundamentalmente a partir del método de tableaux. En esta tesis intentamos completar el panorama del área investigando el problema de la satisfacibilidad para lógicas híbridas usando resolución clásica de primer orden (vía traducciones) y variaciones de un cálculo basado en resolución que opera directamente sobre fórmulas híbridas. Presentamos, en primer lugar, traducciones de complejidad lineal de fórmulas de H(@;!) a lógica de primer orden, que preservan satisfacibilidad. Éstas están concebidas de manera de reducir el espacio de búsqueda de un demostrador automático basado en resolución de primer orden. Luego cambiamos nuestra atención a cálculos que operan directamente sobre fórmulas híbridas. En particular...

Chemical synthesis of hybrid materials based on PAni and PEDOT with polyoxometalates for electrochemical supercapacitors

Vaillant, Julien; Lira-Cantú, Monica; Cuentas Gallegos, A. K.; Casañ Pastor, Nieves; Gómez-Romero, P.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
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Advanced Functional Nanomaterials - from NanoscaleObjects to Nanostructered Inorganic and Hybrid Materials; Hybrid organic–inorganic materials based on conjugated polymers constitute state-of-the-art compounds with recognized technological implications. In the area of energy conversion, production and storage devices, these materials have been applied as electrodes for batteries, supercapacitors, fuel cells or solar cells, among others. Their importance relies on the wide variety of organic and inorganic counterparts that these hybrids can be made of. The properties from each part can be tailored in order to contribute to a final desired characteristic or the combined properties from both. The unique combination of useful properties found in these materials include electronic conductivity (e− or h+), ionic transport, reversible electroactivity, electrooptical properties typical of semiconductors as well as electrochromic, pH- and composition-dependent properties, all of them to add to their polymeric nature. This is an excellent basis for the design of hybrid materials in which either of these properties or their combinations work to enhance or combine with those of a myriad inorganic phases with electronic, magnetic, photochemical...

Organic/Inorganic Hybrid Nanocomposite Infrared Photodetection by Intraband Absorption

Lantz, Kevin Richard
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2011
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The ability to detect infrared radiation is vital for a host of applications that include optical communication, medical diagnosis, thermal imaging, atmospheric monitoring, and space science. The need to actively cool infrared photon detectors increases their operation cost and weight, and the focus of much recent research has been to limit the dark current and create room-temperature infrared photodetectors appropriate for mid-to-long-wave infrared detection. Quantum dot infrared photodetectors (QDIPs) provide electron quantum confinement in three dimensions and have been shown to demonstrate high temperature operation (T>150 K) due to lower dark currents. However, these inorganic devices have not achieved sensitivity comparable to state-of-the-art photon detectors, due in large part to the inability to control the uniformity (size and shape) of QDs during strained-layer epitaxy.

The purpose of this dissertation research was to investigate the feasibility of room-temperature infrared photodetection that could overcome the shortfalls of QDIPs by using chemically synthesized inorganic colloidal quantum dots (CQDs). CQDs are coated with organic molecules known as surface ligands that prevent the agglomeration of dots while in solution. When CQDs are suspended in a semiconducting organic polymer...

Hybrid Sterility and Segregation Distortion in Drosophila pseudoobscura and Drosophila persimilis

McDermott, Shannon
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2012
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Speciation has occurred countless times throughout history, and yet the genetic mechanisms that lead to speciation are still missing pieces. Here, we describe the genetics of two processes that can act alone or together to cause speciation: hybrid sterility and meiotic drive. We use the Drosophila pseudoobscura/D, persimilis species as a model system to study these processes. We expanded on a prior study and saw little variation in strength of previously known hybrid sterility alleles between distinct strains of D. persimilis and the Bogota subspecies of D. pseudoobscura. Introgression of an autosomal, noninverted hybrid sterility allele from the USA subspecies of D. pseudoobscura into D. persimilis demonstrated that the D. pseudoobscura copy of a D. persimilis hybrid sterility factor also causes hybrid male sterility in a D. pseudoobscura bogotana background. This allelism suggests that the introgressed allele is ancestral, but was lost in the Bogota lineage, or that gene flow between D. pseudoobscura USA and D. persimilis moved the sterility-conferring allele from D. persimilis into D. pseudoobscura. To further understand the genetic basis of speciation...

Behavior modeling for hybrid robotic systems

Rawal, Chetan
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
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Herbert G. Tanner; The behavior of a certain class of hybrid robotic systems can be expressed using formal languages. In this work, we show how languages can be generated from discrete abstractions of such hybrid systems; that these languages are regular; and they belong to the star free (SF) class of the Sub-regular hierarchy. Planning and control of hybrid systems is typically difficult due to the computational cost involved in predicting the system’s future states, since the states can take infinite values while evolving along the trajectories of continuous dynamics. A discrete abstraction of the hybrid system can reduce these values to a finite number, thereby fascilitating the solution to the reachability problem. Abstraction enables us to focus on planning the system’s overall behavior through controller sequences observed in the abstract system, instead of dealing with the dynamics associated with each controller. The constraints between controllers enable or disable their temporal sequencing. Similarity of these constraints with those found in formal language theory, allows us to express controller sequences as strings of symbols forming a formal language. A formal language analysis of hybrid systems provides an approach for automatic planning and control design synthesis in single and multi-agent robotic systems. The class of hybrid systems considered in this work have convergent continuous dynamics with parameterized attractors. We model a robot as a hybrid system...

Experimental study of hybrid-knife endoscopic submucosal dissection (ESD) versus standard ESD in a Western country

Peña,Joaquín de-la; Calderón,Ángel; Esteban,José Miguel; López-Rosés,Leopoldo; Martínez-Ares,David; Nogales,Óscar; Orive-Calzada,Aitor; Rodríguez,Sarbelio; Sánchez-Hernández,Eloy; Vila,Juan; Fernández-Esparrach,Gloria
Fonte: Revista Española de Enfermedades Digestivas Publicador: Revista Española de Enfermedades Digestivas
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/02/2014 ENG
Relevância na Pesquisa
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Background: Endoscopic submucosal dissection (ESD) is an effective but time-consuming treatment for early neoplasia that requires a high level of expertise. Objective: The objective of this study was to assess the efficacy and learning curve of gastric ESD with a hybrid knife with high-pressure water jet and to compare with standard ESD. Material and methods: We performed a prospective non-survival animal study comparing hybrid-knife and standard gastric ESD. Variables recorded were: Number of en-bloc ESD, number of ESD with all marks included (R0), size of specimens, time and speed of dissection and adverse events. Ten endoscopists performed a total of 50 gastric ESD (30 hybrid-knife and 20 standard). Results: Forty-six (92%) ESD were en-bloc and 25 (50%) R0 (hybrid-knife: n = 13, 44%; standard: n = 16, 80%; p = 0.04). Hybrid-knife ESD was faster than standard (time: 44.6 ± 21.4 minutes vs. 68.7 ± 33.5 minutes; p = 0.009 and velocity: 20.8 ± 9.2 mm²/min vs. 14.3 ± 9.3 mm²/min (p = 0.079). Adverse events were not different. There was no change in speed with any of two techniques (hybrid-knife: From 20.33 ± 15.68 to 28.18 ± 20.07 mm²/min; p = 0.615 and standard: From 6.4 ± 0.3 to 19.48 ± 19.21 mm²/min; p = 0.607). The learning curve showed a significant improvement in R0 rate in the hybrid-knife group (from 30% to 100%). Conclusion: despite the initial performance of hybrid-knife ESD is worse than standard ESD...