Influence of cross section geometry on the confinement of reinforced concrete columns with CFRP composites

Comunicação apresentada em International Symposium Polymers in Concrete (ISPIC 2006), Guimarães, 2006Confinement effectiveness of externally bonded FRP jackets depends on different parameters namely type of concrete, steel reinforcement, FRP jacket stiffness (type of FRP, number of plies and design of wrap), shape of cross section, radius of corners for non-circular sections, and loading conditions. In order to investigate the effect of some of these parameters on the axial behavior of columns under compression and to quantify the level of confinement exerted on the concrete core, an experimental program has been developed. The experimental research consisted of a sequence of axial compressive tests on cylinders and square prisms. Prisms were divided into three representative groups: sharpedged sections and sections with rounded corners with corner radii equal to either 20mm or 38mm. The results presented in this paper are for the columns which were wrapped with two plies of unidirectional carbon fibers

A novel methodology for the concurrent test of partial and dynamically reconfigurable SRAM-based FPGAs

This poster presents the first truly non-intrusive structural concurrent test approach, with the objective of testing partially and dynamically reconfigurable SRAM-based FPGAs without disturbing their operation. This is accomplished by using a new methodology to carry out the replication of active Configurable Logic Blocks (CLBs), i.e. CLBs that are part of an implemented function that is actually being used by the system, releasing it to be tested in a way that is completely transparent to the system

Asphalt mixtures produced with 100% reclaimed materials

The environmental and economic benefits of using Reclaimed Asphalt Pavement (RAP) material in hot mix asphalt (HMA) applications could be pushed up to the limit, by producing totally recycled HMAs (100% RAP), but the performance of this alternative must be satisfactory. In fact, these mixtures could possibly present a lower performance due to the behaviour of the aged binder, which loses its lighter fractions with time. In order to improve the mixture properties, a binder rejuvenator should be used. Thus, in the present study, the utilization of a used motor oil as a rejuvenator was evaluated. This would allow the modification of the aged binder, restoring some of its original properties and promoting an adequate performance of the mixture. The optimal amount of oil was determined by conventional bitumen tests, using the achievement of a bitumen with a penetration grade above, as the selection criterion for the definition of the amount of oil. Once the amount of rejuvenator (oil) was defined, laboratory specimens were prepared and tested for water sensitivity, permanent deformation, stiffness and fatigue, in order to confirm that the totally recycled mixture will perform as good as a conventional mixture used for comparison purposes.Fundação para a Ciência e a Tecnologia (FCT

Bivariate binomial autoregressive models

This paper introduces new classes of bivariate time series models being useful to fit count data time series with a finite range of counts. Motivation comes mainly from the comparison of schemes for monitoring tourism demand, stock data, production and environmental processes. All models are based on the bivariate binomial distribution of Type II. First, a new family of bivariate integer-valued GARCH models is proposed. Then, a new bivariate thinning operation is introduced and explained in detail. The new thinning operation has a number of advantages including the fact that marginally it behaves as the usual binomial thinning operation and also that allows for both positive and negative cross-correlations. Based upon this new thinning operation, a bivariate extension of the binomial autoregressive model of order one is introduced. Basic probabilistic and statistical properties of the model are discussed. Parameter estimation and forecasting are also covered. The performance of these models is illustrated through an empirical application to a set of rainy days time series collected from 2000 up to 2010 in the German cities of Bremen and Cuxhaven.publishe

Run-time management of logic resources on reconfigurable systems

Dynamically reconfigurable systems based on partialand dynamically reconfigurable FPGAs may have theirfunctionality partially modified at run-time withoutstopping the operation of the whole system.The efficient management of the logic space availableis one of the biggest problems faced by these systems.When the sequence of reconfigurations to be performed isnot predictable, resource allocation decisions have to bemade on-line. A rearrangement may be necessary to getenough contiguous space to implement incomingfunctions, avoiding the spreading of their components andthe resulting degradation of system performance.A new software tool that helps to handle the problemsposed by the consecutive reconfiguration of the same logicspace is presented in this paper. This tool uses a novel on--line rearrangement procedure to solve fragmentationproblems and to rearrange the logic space in a waycompletely transparent to the applications currentlyrunnin

Avaliação do desempenho de misturas betuminosas temperadas

A diminuição do consumo de combustíveis e das emissões de gases com efeitos de estufa são um grande desafio da sociedade actual. No fabrico de misturas betuminosas desenvolveram-se recentemente diversas tecnologias para redução da temperatura de produção e aplicação em obra que promoveram a produção de misturas betuminosas temperadas (MBT). Inúmeros benefícios no uso das MBT têm potenciado o seu crescente desenvolvimento, destacando-se a redução das emissões no fabrico e a diminuição do combustível gasto nos queimadores. Na colocação em obra, as MBT garantem uma trabalhabilidade adequada à sua aplicação e compactação a menores temperaturas, reduzindo a produção de fumos, possibilitando o transporte a longas distâncias, alargando a época de pavimentação, e permitindo a sua aplicação a temperaturas atmosféricas inferiores. Neste trabalho compara-se o desempenho mecânico de uma mistura betuminosa (AC 14 Surf 50/70) produzida a temperaturas convencionais e a menores temperaturas (125 a 135 ºC), através da introdução de dois aditivos (Sasobit® e Cecabase®). Foram determinadas as propriedades dos ligantes base e modificados (penetração, anel e bola, viscosidade e reologia) para observação do comportamento, determinação das temperaturas de fabrico e aferição da percentagem de aditivo. A caracterização das misturas foi realizada inicialmente em laboratório (propriedades volumétricas, sensibilidade à água e resistência à deformação permanente), realizando-se em seguida um trecho experimental onde foram extraídos provetes para determinação das características anteriormente referidas, além do módulo de rigidez. Em comparação com a mistura convencional, conseguiu-se reduzir a temperatura das MBT cerca de 15 a 25 ºC mantendo idênticas propriedades volumétricas e mecânicas em laboratório, o que não se conseguiu no trecho devido a um problema de contaminação com o combustível usado no queimador

Programmable logic devices: a test approach for the Input / Output blocks and Pad-to-Pin interconnections

Dynamically reconfigurable systems based on partial and dynamically reconfigurable FPGAs may have their functionality partially modified at run-time without stopping the operation of the whole system. The efficient management of the logic space available is one of the biggest problems faced by these systems. When the sequence of reconfigurations to be performed is not predictable, resource allocation decisions have to be made on-line. A rearrangement may be necessary to get enough contiguous space to implement incoming functions, avoiding the spreading of their components and the resulting degradation of system performance.A new software tool that helps to handle the problems posed by the consecutive reconfiguration of the same logic space is presented in this paper. This tool uses a novel on-line rearrangement procedure to solve fragmentation problems and to rearrange the logic space in a way completely transparent to the applications currently running

Reliability analysis of solar-gas hybrid receivers for Central Tower Plants

A novel Solar-Gas Hybrid Receiver (SGHR) that combines the function of a solar receiver and a gas boiler in a single device is presented. This concept requires less equipment and maintenance compared to the Solar Gas Hybrid(SGH) concept, in which the boiler and the solar receiver (SR) are independent devices. The economic benefit is attributed to the increased sharing of infrastructures. Additionally, it has less thermal stress, cycles and shocks, which reduce the failure risk. However, the additional benefit in the reliability of these receivers has not been analyzed so far. In this work, a mathematical model of SGHR is presented. It determines the stress in steady state which is used to estimate the allowable transient stress in order to achieve the required 30 years life design. The results show that the SGHR is exposed to lower thermal stress due to much better temperature distribution. Moreover the higher …info:eu-repo/semantics/publishedVersio

Social network measures to match analysis in soccer : a survey

In this study we will present the most common and adequate network measures to analyse graph properties and to inspect the prominence of each player on a soccer team. Both approaches can provide a range of useful information. This kind of analysis will help to identify the prominence of players and also characterize the collective organization and patterns of the teams. General measures and centrality levels will be described and the applications will be discussed. By using social network analysis will be possible to quantify the structure of play and predict some behaviour. Such methodology will add new options to the field of match analysis.info:eu-repo/semantics/publishedVersio

Development and use of a new medium to detect yeasts of the genera Dekkera/Brettanomyces

Aims: The objectives of this work were to develop a selective and/or differential medium able to effciently recover Dekkera/Brettanomyces sp. from wine-related environments and to determine the relationship between these yeasts and the 4-ethylphenol content in a wide range of wines. Methods and Results: The selectivity of the developed medium was provided by the addition of ethanol, as single carbon source, and cycloheximide. The inclusion of bromocresol green evidenced acid-producing strains. The inclusion of p-coumaric acid, substrate for the production of 4-ethylphenol, enabled the differentiation by smell of Dekkera/Brettanomyces sp. from all other yeast species growing in the medium. The medium was used either by plating after membrane filtration or by the Most Probable Number (MPN) technique. In 29 white and 88 red randomly collected wines, these yeasts were found only in red wines at levels up to 2500 MPN ml±1, but constituted less than 1% of the total microbial flora. In red wines, 84% showed detectable amounts of 4-ethylphenol up to 4430 lg l±1 while 28% of the white wines showed detectable levels up to 403 lg l±1. Conclusions: The use of the medium proposed in this work evidenced the presence of low relative populations of Dekkera/Brettanomyces sp. even in wines contaminated by fast-growing yeasts and moulds. Significance and Impact of the Study: Further ecological studies on Dekkera/Brettanomyces sp. should take into account the use of highly specific culture media in order to establish their true occurrence in natur