806 research outputs found

    NHL 3.5 mortars with scrap tire rubber

    Get PDF
    The use of wastes and industrial by-products as building materials is an important issue in order to decrease costs with waste management and the embodied energy of building products. Scrap tire rubber has been studied as aggregate for cementitious materials. Natural hydraulic limes are natural binders with particular characteristics of both air and hydraulic binders. Their specifications became stricter with the last version of EN 459-1:2010. In this study scrap tire rubber was used as additional aggregate of mortars, based on NHL3.5 and natural sand. Different particle size fractions and proportions of scrap tire rubber were used: a mix obtained almost directly from industry (only after sieving for preparation of particle sizes similar to mortar aggregate) and separated fine, medium and coarse fractions; 0%, 18%, 36% and 54% weight of binder, corresponding to 2.5%, 5% and 7.5% weight of sand. The influence of the rubbers´ additions on the mortars´ fresh state, mechanical and physical performance is presented, namely by flow table consistency, water retention, fresh bulk density, dynamic elasticity modulus, flexural and compressive strength, open porosity and bulk density, capillary absorption, drying and thermal conductivity. The use of the rubber mix coming from the waste tire industry seems advantageous and may open possibilities for use as raw material by the mortars industry

    ICT Diffusion, inward foreign direct investment,and entrepreneurship in developing countries:a research note

    Get PDF
    The last decades have stablished the fundamental importance of technological progress for economic growth and wealth creation. Most new technology is created in developed countries. For these countries, the fundamental problem for growth is to harness the economic value of new inventions by converting them into new products, processes and organizational means. Entrepreneurship plays a fundamental role in this course of events (Shane 2001; Michelacci 2003; Acs et al. 2004; 2009). In developing countries the diffusion of new technologies plays an essential role in fostering growth

    O Reequipamento da Indústria de Defesa. Subsídios para uma Política de Armamento

    Get PDF
    Este trabalho começa por notar que, não obstante a problemática do reequipamento das Forças Armadas (FA) vir a merecer o interesse expresso de sucessivos Governos, o facto é que as FA consideram que o seu equipamento continua a apresentar graves deficiências. Por outro lado, admitindo que é do interesse estratégico nacional a manutenção de uma expressão mínima suficiente de uma “indústria de defesa”, na sequência e em cumprimento dos objectivos programáticos também estabelecidos por sucessivos Governos, é necessário e urgente definir uma política para a reestruturação deste sector. Aborda-se depois a questão do âmbito da política a definir para concluir pela conveniência englobar ambas as vertentes, ou seja: “É necessário e urgente definir uma “Política de Armamento” que aponte os objectivos e as vias institucionais que norteiem, enquadrem e apoiem o reequipamento das Forças Armadas e, simultânea e conjugadamente, concorram para a reestruturação e desenvolvimento da Indústria de Defesa” Depois de analisar a situação e as implicações da envolvente externa e do quadro nacional, conclui-se o trabalho com a apresentação de “linhas gerais de acção”, como contributo para a definição da Política de Armamento

    Interpreting the Solution Architect’s Role at a leading IT and Consultancy Company

    Get PDF
    At the end of the twentieth century, an individual or a small company could design and develop an application or even some bigger and scalable systems. However, due to their increasing complexity, project size and required higher levels of integration, the need for new roles and processes associated with software development drastically increased, calling for skills to assure the integrity and effectiveness of solutions. A new role, called “Solution Architect”, emerged over time and has been formally used in leading companies such as Cisco, IBM, Microsoft, Oracle and SAP, but it is still lacking agreement on its scope and responsibilities. Having the retail sector as the context in which a leading IT and consultancy company operates, this research builds upon the experience of seven Solution Architects from a pool of fourteen inquiring them on their perceptions about their roles in order to better understand the required skills and boundaries of this new role against more established architectural roles. At the end of this research, it was clear that the interpretations of this role’s span across a project’s lifecycle as well as the boundaries to other roles such as the Enterprise Architect’s one were not the same. Nevertheless, the consultancy side of the Solution Architect role gathered the most consensuses as opposed to the more traditional technical side, which wasn’t selected by any Solution Architect. Anyway, the scope dilemma still persists within a project leading to a role overlap between Enterprise and Solution Architect.This work is supported by FEDER funding through the Competitiveness Factors Operational Programme - COMPETE and national funding through FCT - Foundation for Science and Technology under the project FCOMP-01-0124-FEDER-022674

    RODA - A Service-Oriented Repository to Preserve Authentic Digital Objects

    Get PDF
    4th International Conference on Open RepositoriesThis presentation was part of the session : Fedora User Group PresentationsDate: 2009-05-20 03:30 PM – 05:00 PMIn mid 2006, the Portuguese National Archives (Directorate-General of the Portuguese Archives) launched a project called RODA (Repository of Authentic Digital Objects) aiming at identifying and bringing together all the necessary technology, human resources and political support to carry out long-term preservation of digital materials being produced by the Portuguese public administration. As part of the original goals of RODA was the development of a digital repository capable of ingesting, managing and providing access to the various types of digital objects produced by national public institutions. The development of such repository should be supported by open-source technologies and, as much as possible, be based on existing standards. Since RODA is nearly finished, this communication aims at describing its main results.European Union; POAP; Ministry of Culture; Portuguese Republi

    Controlo de bulking filamentoso: Acompanhamento de um processo de tratamento de efluentes do SIDVA

    Get PDF
    Na ETAR de Serzedelo existiam problemas de separação de sólidos – foaming – provocados pelo crescimento excessivo de Nocardia spp, nas bacias de arejamento. Na tentativa de resolução deste problema foram realizados vários ensaios, tais como: adição de sais, anti-espumante, controlo do arejamento e alteração da razão F/M de funcionamento. Uma vez que estas tentativas foram ineficazes, optou-se por aplicar cloro na superfície – aspersão superficial. Este trabalho teve como objectivo o acompanhamento da utilização de cloro na superfície dos tanques de arejamento. A dosagem inicial de 10 gCl2/m²/dia e a dosagem máxima utilizada foi 17 gCl2/m²/dia. Para estas dosagens, a diminuição das espumas não foi eficaz, no período do ensaio industrial. No entanto, a eficiência de tratamento não foi alterada, uma vez que a comunidade microbiana e a sua actividade não foram significativamente afectadas

    Power Flow Analysis of HVAC and HVDC Transmission Systems for Offshore WindParks

    Get PDF
    corecore