Spelling suggestions: "subject:"highperformance"" "subject:"highperformance""
121 |
Pilares de concreto de alto desempenho: fundamentos e experimentação / High performance concrete columns: principles and experimentationLima, Flávio Barboza de 30 October 1997 (has links)
O uso de concreto de alto desempenho constitui tendência irreversível, devido às vantagens que apresenta em relação aos concretos de resistência usual, principalmente na execução de pilares de edifícios, pois as áreas das seções transversais podem ser reduzidas. Este trabalho trata da obtenção e do estudo teórico e experimental de pilares de concreto de alto desempenho, analisando o comportamento de modelos, solicitados à compressão centrada e flexão normal composta. Foram analisados pilares de seções transversais quadradas de 20cm x 20cm e retangulares de 15cm x 30cm e 12cm x 30cm, dimensões que representam pilares usuais em estruturas de edifícios. Na compressão centrada ficou caracterizado que o estado limite último foi atingido por ruptura da seção mais solicitada e comprovado que a ruptura ocorreu quando o núcleo, definido pelo perímetro considerado pelos eixos dos estribos, se rompeu. Nos ensaios de flexão normal composta os resultados mostraram que as hipóteses de distribuição de tensões, utilizadas para os concretos de resistências usuais, não devem ser consideradas para concreto de alta resistência. As forças normais experimentais e as teóricas, calculadas por um modelo proposto pelo Autor, ficaram iguais enquanto que, para os momentos fletores, os valores experimentais ficaram muito acima dos teóricos. / The use of high performance concrete is an irreversible tendency in structural design due to the advantages it presents, compared to the concrete of usual strength, these advantages can be seen mainly in the execution of buildings columns as the cross sections can be reduced. This thesis is about the theoretical and experimental study to obtain high performance concrete columns. The behaviour of models subjected to axial load and bending plus axial load was analysed. Columns with the square (20cm x 20cm) and rectangular (15cm x 30cm and 12cm x 30cm) cross sections were studied, because they are the usual buildings columns dimensions. As far as axial load is concerned, the ultimate state limit was reached when the mostly demanded section broke. It was proven that the rupture occurred when the core, defined by the perimeter considered by the axial stirrups, broke. The results of bending plus axial load tests have shown that the distribution of stress hypotheses used for concrete of usual strength must not be considered for high strength concrete. The experimental axial forces and the internal ones calculated by a given model were the same, whereas the experimental values for the internal moments were much higher.
|
122 |
Chitin Microparticles (CMPs) Induce M1 Macrophage Activation via Intracellular TLR2 Signaling MechanismUnknown Date (has links)
Chitin Microparticles (CMPs, 1-10um), a special form of the ubiquitous and nontoxic
polysaccharide Chitin (GlcNAc), is capable of inducing a switch in macrophages
from the wound-healing M2 phenotype to the classically activated pro-inflammatory M1
phenotype; which has therapeutic implications in allergy and cancer. We hypothesized
that TLR2 forms a complex with CMPs and Chitin-Binding Proteins (CBPs) at the
surface of peritoneal macrophages and remains with that complex after internalization to
initiate downstream signaling events, leading to the production of the M1 cytokine, TNFalpha.
Our results from experiments performed in RAW 264.7 cells show that TLR2 and
TLR1, but not TLR6, are associated with the CMP binding fraction, and that both TLR1
and TLR2 might be important for M1 activation as a result of CMP phagocytosis. This
project sheds light on CMP as a potential therapeutic agent and provides more evidence
for a phagocytosis-dependent TLR2 signaling pathway. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
|
123 |
Projeto estrutural de vigas de concreto de alto desempenho / Structural design of high performance concrete beamsAndrade Júnior, João Paulo de 10 February 1999 (has links)
Este trabalho fornece uma visão geral sobre a aplicação, o dimensionamento e o detalhamento de elementos fletidos de concreto de alto desempenho (CAD), armados ou protendidos, com particular atenção para estes últimos. Procurou-se, sempre que possível, realçar as situações nas quais os atuais procedimentos normalizados permanecem válidos, ou não, para o cálculo das vigas de CAD. Na introdução, apresenta-se a viabilidade econômica da aplicação do concreto de alto desempenho nas vigas. No capítulo referente à retração e à fluência, abordam-se procedimentos válidos para o CAD, os quais apresentam melhor correlação com os resultados experimentais que a obtida através do ACI 209 (1982) ou do CEB-FIP (1990). No que se refere à flexão, apresenta-se um diagrama tensão-deformação retangular, e comparam-se os seus resultados para concretos usuais e de alto desempenho, com os obtidos pelo diagrama parábola-retângulo, em termos de consumo de armadura. No capítulo referente ao cisalhamento, apresentam-se recomendações para a utilização do Método Padrão e do Modelo de Treliças de Diagonais de Inclinação Variável para o cálculo da armadura transversal em vigas de CAD. Para o cálculo dos deslocamentos causados por ações de curta duração, confirma-se a validade da metodologia de Branson para as vigas de CAD. Os deslocamentos adicionais causados por ações de longa duração também são considerados, incluindo-se metodologias para as vigas de concreto armado e para as pré-moldadas protendidas. Exemplos de dimensionamento são feitos para todos os itens apresentados, considerando-se uma viga pré-moldada de 30 m de comprimento, seção \"T\", com pós-tensão e fck = 70 MPa. / This work provides an overview of use and design of the high performance concrete (HPC) flexural members, reinforced or prestressed, with particular attention for the last ones. Cases in which procedures of the modern codes for calculation of HPC beams remain valid were enhanced. In the introduction, the economic viability of high performance concrete beams is presented. In the chapter about shrinkage and creep, valid procedures for HPC are presented. These procedures have better correlation with the actual results than those relative to ACI 209 (1982) or CEB-FIP (1990). A rectangular stress block is presented, and its results for usual and high performance concrete are compared with those from the parabolic-rectangular stress block, in terms of consume of steel. In the chapter about shear, recommendations for use of Standard Method and Variable Angle Truss Model for HPC beams are presented. For the calculation of short term deflections, the validity of Branson\'s Method for high performance concrete beams is confirmed. Sustained load deflections are also considered, and including procedures for reinforced beams and for precast prestressed ones. For all the considered topics, examples are presented for a 30 m span precast post-tensioned beam, \"T\" cross section and fck = 70 MPa.
|
124 |
Determination of organic compounds by high-performance liquid chromatography with conductometric detection.January 1993 (has links)
by Chuen-shing Mok. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 192-193). / Chapter Chapter 1 --- INTRODUCTION --- p.1 / Chapter Chapter 2 --- INSTRUMENTATION AND THEORY --- p.9 / Chapter Chapter 3 --- INDIRECT CONDUCTOMETRIC DETECTION OF AMINO ACIDS AFTER HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC SEPARATION --- p.17 / Chapter Chapter 4 --- DETERMINATION OF MONOSODIUM GLUTAMATE IN FOODS WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY USING INDIRECT CONDUCTOMETRIC DETECTION --- p.52 / Chapter Chapter 5 --- HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC DETERMINATION OF ACTIVE INGREDIENTS IN COUGH-COLD SYRUPS WITH INDIRECT CONDUCTOMETRIC DETECTION --- p.83 / Chapter Chapter 6 --- HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC DETERMINATION OF ATROPINE AND ATROPINE- LIKE ALKALOIDS IN PHARMACEUTICAL PREPARATIONS WITH INDIRECT CONDUCTOMETRIC DETECTION --- p.144 / Chapter Chapter 7 --- CONCLUSION --- p.194
|
125 |
HPLC method development for the analysis of electroplating baths used in the electronic industry.January 2002 (has links)
Sin Wai-Chu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Abstracts in English and Chinese. / ABSTRACT --- p.i / 論文摘要 --- p.ii / ACKNOWLEDGEMENT --- p.iii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Electroplating history --- p.1 / Chapter 1.2 --- Electroplating bath --- p.7 / Chapter 1.3 --- Electroplating analytical methods --- p.8 / Chapter 1.3.1 --- Metal content and elemental impurities analysis --- p.10 / Chapter 1.3.2 --- "Metal complex, inorganic anion and cation analysis" --- p.11 / Chapter 1.3.3 --- Organic brighteners and levelers analysis --- p.12 / Chapter 1.4 --- HPLC literature review --- p.15 / Chapter 1.5 --- My research work --- p.16 / Chapter 1.6 --- References for Chapter 1 --- p.19 / Chapter Chapter 2 --- General Experimental --- p.23 / Chapter 2.1 --- The HPLC System --- p.23 / Chapter 2.2 --- The factors that affect the separation --- p.26 / Chapter 2.2.1 --- The composition of the solvent system --- p.27 / Chapter 2.2.2 --- The selection of column --- p.30 / Chapter 2.2.3 --- The most suitable analytical wavelength for UV detection --- p.34 / Chapter 2.3 --- Challenges in analyzing electroplating baths solution --- p.35 / Chapter 2.3.1 --- High metal content --- p.36 / Chapter 2.3.2 --- Strong ligand or complexing agent --- p.36 / Chapter 2.3.3 --- Interference --- p.37 / Chapter 2.3.4 --- Extreme pH --- p.37 / Chapter 2.3.5 --- Other difficulties --- p.38 / Chapter 2.3.6 --- Maintenance of HPLC instrument --- p.38 / Chapter 2.4 --- References for Chapter 2 --- p.38 / Chapter Chapter 3 --- Palladure 200 bath HPLC analysis --- p.41 / Chapter 3.1 --- Introduction --- p.41 / Chapter 3.2 --- Experimental --- p.43 / Chapter 3.3 --- Problems in the existing UV analysis for monitoring Palladure200 process --- p.45 / Chapter 3.4 --- HPLC method development for monitoring Palladure 200 process --- p.49 / Chapter 3.5 --- Analysis of aged Palladure 200 plating bath from production line --- p.55 / Chapter 3.6 --- Conclusion --- p.57 / Chapter 3.7 --- References for Chapter 3 --- p.58 / Chapter Chapter 4 --- Nickel PC3 bath HPLC analysis --- p.59 / Chapter 4.1 --- Introduction --- p.59 / Chapter 4.2 --- Experimental --- p.60 / Chapter 4.3 --- Problems in the existing Titration method for monitoring Nickel PC3 process --- p.62 / Chapter 4.4 --- HPLC method development for monitoring Nickel PC3 process --- p.63 / Chapter 4.4.1 --- Identify individual component of Nickel PC3 process --- p.63 / Chapter 4.4.2 --- Set up a calibration curve for the Nickel PC3 Additive --- p.67 / Chapter 4.4.3 --- Analysis of aged Nickel PC3 plating bath from production line --- p.68 / Chapter 4.5 --- Conclusion --- p.71 / Chapter 4.6 --- References for Chapter 4 --- p.72 / Chapter Chapter 5 --- Solderon SC bath HPLC analysis --- p.73 / Chapter 5.1 --- Introduction --- p.73 / Chapter 5.2 --- Experimental --- p.74 / Chapter 5.3 --- Instability in the existing Cyclic Voltammetric Stripping (CVS) method for monitoring Solderon SC process --- p.76 / Chapter 5.4 --- HPLC method development for monitoring Solderon SC process --- p.77 / Chapter 5.4.1 --- Identify the individual components --- p.77 / Chapter 5.4.2 --- Set up a calibration curve for the Solderon SC Primary --- p.82 / Chapter 5.4.3 --- Analysis of aged Solderon SC plating bath from production line --- p.84 / Chapter 5.5 --- Conclusion --- p.86 / Chapter 5.6 --- References for Chapter 5 --- p.86 / Chapter Chapter 6 --- Copper Gleam PPR bath HPLC analysis --- p.87 / Chapter 6.1 --- Introduction --- p.87 / Chapter 6.2 --- Experimental --- p.89 / Chapter 6.3 --- Problems in the existing Cyclic Voltammetric Stripping (CVS) method for monitoring Copper Gleam PPR process --- p.91 / Chapter 6.4 --- HPLC method development for monitoring Copper Gleam PPR process --- p.92 / Chapter 6.4.1 --- Identify Individual components and copper PPR additivein standard bath --- p.92 / Chapter 6.4.2 --- Set up a calibration curve for the Copper Gleam PPR Additive --- p.95 / Chapter 6.4.3 --- Analysis of aged Copper Gleam PPR plating bath from production line --- p.96 / Chapter 6.4.5 --- Study of H202 effect --- p.101 / Chapter 6.4.6 --- Study of air agitation effect --- p.104 / Chapter 6.4.7 --- Study of Copper anode effect --- p.105 / Chapter 6.5 --- Conclusion --- p.107 / Chapter 6.6 --- References for Chapter 6 --- p.107 / Chapter Chapter 7 --- Silverjet220 bath HPLC analysis --- p.109 / Chapter 7.1 --- Introduction --- p.109 / Chapter 7.2 --- Experimental --- p.110 / Chapter 7.3 --- HPLC method development for monitoring Silverjet 220 process --- p.112 / Chapter 7.3.1 --- Identify individual components and Silverjet 220 Additive in the plating bath --- p.112 / Chapter 7.3.2 --- Optimize the condition for HPLC analysis --- p.117 / Chapter 7.3.3 --- Analysis of aged Silverjet 220 plating bath from production line --- p.119 / Chapter 7.4 --- Conclusion --- p.122 / Chapter 7.5 --- References for Chapter 7 --- p.123 / Chapter Chapter 8 --- Conclusions and Further Studies --- p.124 / Chapter 8.1 --- Conclusions --- p.124 / Chapter 8.2 --- Further Studies --- p.126 / APPENDIX --- p.128 / The User guide for HPLC --- p.128 / HPLC System Calibration Maintenance --- p.135 / HPLC System Preventive Maintenance --- p.145
|
126 |
Wavelet Compression for Visualization and Analysis on High Performance ComputersLi, Shaomeng 31 October 2018 (has links)
As HPC systems move towards exascale, the discrepancy between computational power and I/O transfer rate is only growing larger. Lossy in situ compression is a promising solution to address this gap, since it alleviates I/O constraints while still enabling traditional post hoc analysis. This dissertation explores the viability of such a solution with respect to a specific kind of compressor — wavelets. We especially examine three aspects of concern regarding the viability of wavelets: 1) information loss after compression, 2) its capability to fit within in situ constraints, and 3) the compressor’s capability to adapt to HPC architectural changes. Findings from this dissertation inform in situ use of wavelet compressors on HPC systems, demonstrate its viabilities, and argue that its viability will only increase as exascale computing becomes a reality.
|
127 |
Aplicação de conceitos reológicos na tecnologia dos concretos de alto desempenho / The application of rheological concepts on the high performance concretes technologyCastro, Alessandra Lorenzetti de 29 January 2007 (has links)
Do ponto de vista reológico, o concreto fresco flui como um líquido. Sendo assim, o seu comportamento no estado fresco deve ser estudado a partir dos conceitos da reologia, ciência voltada para o estudo das deformações e escoamento de um fluido sob a influência de tensões. As estruturas bem planejadas, dependendo do processo adotado para sua confecção, são executadas em tempo muito pequeno após a mistura dos materiais que irão constituir os concretos. Assim, a trabalhabilidade do concreto é um parâmetro importante a ser estudado, tanto por facilitar o lançamento do material quanto pelas decisões relacionadas com a forma desse lançamento. Tradicionalmente, a trabalhabilidade do concreto está associada à sua consistência, expressa em termos de abatimento obtido no ensaio de tronco de cone, que, apesar de ser um método de ensaio bastante utilizado, não a quantifica totalmente. Isto porque o concreto se comporta como um fluido binghamiano, sendo, então, caracterizado por dois parâmetros reológicos: a tensão de escoamento e a viscosidade plástica. Assim, o presente trabalho determina alguns parâmetros de medida, a partir de conceitos reológicos, para a verificação do comportamento de alguns tipos de concreto de alto desempenho no estado fresco, com adição de sílica ativa. Para isso, foram usados tanto os métodos de ensaios tradicionais - ensaio de abatimento de tronco de cone e consistômetro de Ve-Be - quanto equipamentos mais modernos - reômetro. Uma modificação do ensaio de abatimento tradicional também foi usada como uma tentativa de simplificar a determinação dos parâmetros reológicos que caracterizam o comportamento dos concretos frescos. A capacidade dos concretos escoarem sob influência do seu peso próprio foi avaliada através do ensaio da caixa L. A identificação da natureza reológica dos concretos foi feita com o auxílio de um reômetro. A trabalhabilidade dos concretos foi avaliada a partir dos métodos de ensaio que medem os dois parâmetros reológicos e sua perda ao longo do tempo foi associada à evolução dos parâmetros medidos. Apesar de terem sido classificadas como misturas fluidas, nenhum concreto apresentou escoamento suficiente que o caracterizasse como um material auto-adensável, porém apresentou bom escoamento sob a energia de um vibrador. A natureza reológica dos concretos foi identificada como sendo realmente semelhante a um fluido binghamiano. A trabalhabilidade, bem como sua perda ao longo do tempo, foram associadas à evolução dos parâmetros reológicos: observou-se um aumento da tensão de escoamento (ou torque de escoamento), enquanto a viscosidade plástica (ou viscosidade de torque) permaneceu praticamente constante durante os 60 minutos em que o comportamento foi acompanhado. Conclui-se que para a trabalhabilidade dos CAD, há inúmeros outros fatores importantes a serem considerados no prosseguimento da pesquisa, os quais deverão levar em conta parâmetros associados à produção, ao transporte e ao lançamento do material. / From the rheological point of view, the fresh concrete flows as a liquid. In such case, its fresh behavior should be studied from the concepts of rheology, the science which concerns the study of deformation and flow of a fluid under stress influence. The well designed structures, depending on the process considered in their production, are performed in a very short time after the mixture of the materials that will constitute the concretes. Thus, the concrete workability is an important parameter to be studied, even for facilitating the material placement and for the decisions related with the method of this process. Traditionally, the concrete workability is associated to its consistency, expressed in terms of the slump value measured by the slump test that, in spite of being a quite used test, does not quantify it totally. It happens because the concrete behaves as a Bingham fluid, being described by two rheological parameters: the yield stress and the plastic viscosity. Thus, the present research determines some measure parameters from rheological concepts to verify the behavior of some types of fresh high performance concrete (with silica fume addition). For this, both traditional test methods - slump test and Vebe consistometer - and more recent equipments - rheometer - were used. A modification of the traditional slump test was also used as an attempt to simplify the determination of the rheological parameters that describe the fresh concretes behaviors. The capacity of the concretes flow under the influence of their own weight was evaluated by the L-box test. The identification of the concretes rheological behavior was made with a rheometer. The concretes workability was evaluated from test methods that measure the two rheological parameters and its loss over time was associated to the evolution of the measured parameters. In spite of being classified as fluid mixtures, none of the concretes presented enough flow to describe it as a self-compacting material; however they presented a good flow under vibration energy. The concrete rheological behavior was identified as being similar to a Bingham fluid. The workability, as its loss over time, was associated to the evolution of the rheological parameters: an increase of the yield stress (or flow resistance) was observed, while the plastic viscosity (or torque viscosity) stayed practically constant during the 60 minutes in which the behavior was followed. It is concluded that for the high performance concretes workability, there are other several important factors to be considered in the research pursuit, which should consider the parameters associated to the material\'s production, transport and placement.
|
128 |
Projeto de pilares de concreto de alto desempenho / Design of high performance concrete columnsAguiar, Eduardo Aurélio Barros 25 April 2000 (has links)
O presente trabalho fornece uma visão geral sobre a aplicação, o dimensionamento e o detalhamento de pilares confeccionados com concreto de alto desempenho (CAD), cujo principal atributo analisado é a resistência do concreto à compressão. A ênfase do estudo é dada à aplicação do CAD em pilares de edifícios. São apresentadas as principais diferenças entre pilares de CAD e pilares confeccionados com concretos de baixa resistência (fck < 40 MPa), sendo abordados, com base em códigos vigentes e em resultados experimentais, os diagramas tensão-deformação mais indicados, as formas de consideração das não-linearidades física e geométrica, as excentricidades a serem consideradas no dimensionamento, as causas e a forma de prevenção do fenômeno da perda do cobrimento (característico de pilares de CAD), a importância e a forma de consideração do confinamento e algumas disposições construtivas necessárias para o bom desempenho do pilar. Procurou-se, sempre que possível, apresentar os aspectos que não necessitam de alterações, ou seja, que podem ser considerados da mesma forma para concretos de baixa e de alta resistência. Finaliza-se com a apresentação de alguns exemplos de dimensionamento de pilares de CAD, abordando os tópicos analisados ao longo do texto. / The present work provides an overview of use and design of columns made with high performance concrete (HPC), whose main analyzed attribute is the compression strength of the concrete. The emphasis of the study is given to the application of HPC in columns of buildings. The main differences are presented among columns of HPC and columns made with low strength concrete (fck < 40 MPa), being approached, on base in effective codes and in experimental results, the more suitable stress-strain diagrams, the forms of consideration of the physical and geometrical non-linearities, the eccentricities to be considered in the design, the causes and the form of prevention of the phenomenon of the spalling of the concrete cover (characteristic of HPC columns), the importance and the form of consideration of the confinement and some necessary constructive dispositions for the good performance of the column. It was sought, whenever possible, to present the aspects that don\'t need alterations, that is to say, that can be considered in the same way for low and high strength concretes. It concludes with the presentation of some examples of design of HPC columns, approaching the topics analyzed along the text.
|
129 |
Studies of flow injection system for micelle-assisted preconcentration of PAHs coupled with HPLCLi, Cheuk Fai 01 January 2009 (has links)
No description available.
|
130 |
營實HPLC指紋圖譜研究初探張雅茗, 01 January 2013 (has links)
No description available.
|
Page generated in 0.0453 seconds