Transmission costs allocation based on optimal re-dispatch

Congestion management of transmission power systems has achieve high relevance in competitive environments, which require an adequate approach both in technical and economic terms. This paper proposes a new methodology for congestion management and transmission tariff determination in deregulated electricity markets. The congestion management methodology is based on a reformulated optimal power flow, whose main goal is to obtain a feasible solution for the re-dispatch minimizing the changes in the transactions resulting from market operation. The proposed transmission tariffs consider the physical impact caused by each market agents in the transmission network. The final tariff considers existing system costs and also costs due to the initial congestion situation and losses. This paper includes a case study for the 118 bus IEEE test case.

Re-use assessment of thermoset composite wastes as aggregate and filler replacement for concrete-polymer composite materials: a case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

Privatization and entry of a foreign firm with demand uncertainty

We investigate the effects of trade with a foreign firm and privatization of the domestic pubUc firm on an incentive for the domestic firm to reduce costs by undertaking R&D investment, under demand uncertainty. We suppose that the domestic firm is less efficient than the foreign firm. However, the domestic firm can lower its marginal costs by conducting cost-reducing R&D investment. We examine the impacts of entry of a foreign firm, and the effects of demand uncertainty, on decisions upon cost-reducing R&D investment by the domestic firm and how these affect the domestic welfare.

Estruturas flex��veis multicamada para gest��o de humidade

O conforto �� uma necessidade para a maioria das pessoas. A busca de vestu��rio que se adapte ��s condi����es ambientais tornou-se essencial. Queremos materiais que nos mantenham quentes ou frescos, em condi����es de frio ou calor, e sejam capazes de nos manter secos se chover, ou se transpirarmos, devido a actividade intensa, ou simplesmente porque est�� quente. O objectivo principal deste trabalho era desenvolver uma estrutura multicamada respir��vel, para posterior aplica����o num sapato perfurado, tornando-o respir��vel e imperme��vel. S��o j�� aplicados em pe��as de roupa e cal��ado, materiais que permitem essa gest��o de calor e humidade ��� as membranas. Neste trabalho, foram apresentadas algumas membranas, de fabricantes e materiais diferentes, que foram testadas de modo a obter valores para a transmiss��o de vapor de ��gua e classific��-las quanto �� sua respirabilidade, relativamente a uma membrana de refer��ncia. Foram feitos testes com as membranas isoladas, laminadas e com sobreposi����o de duas membranas laminadas. Verificou-se que a laminagem n��o diminu��a, substancialmente, a respirabilidade das membranas. J�� a sobreposi����o de membranas, demonstrou diminuir em 35 % a respirabilidade das membranas. A membrana com melhor desempenho �� constitu��da por um pol��mero de base ��ter e blocos de amida (PEBA). Ainda pouco aplicado em vestu��rio e cal��ado, mas com algum potencial, s��o os n��o-tecidos impregnados com pol��meros super absorventes (SAP���s). Estes podem absorver at�� 500 vezes o seu peso em ��gua, dependendo da quantidade de SAP���s com que o n��o tecido �� impregnado e da aplica����o final. Esta capacidade de adsor����o seria uma mais-valia, em condi����es de chuva intensa, mas por outro lado, se atingir a satura����o, n��o permite a entrada ou sa��da de ar, o que poderia levar a desconforto no utilizador. Por fim, foi utilizado um manequim t��rmico (p��), onde se testaram diferentes cal��ados, verificando-se que s�� �� poss��vel perder calor e vapor de ��gua pela sola do sapato se esta se encontrar perfurada e utilizar um sistema respir��vel. Futuramente, pretende-se aplicar uma outra camada de n��o-tecido, na outra face das membranas j�� testadas, de modo a criar um sistema de 3 camadas, e testar a sua respirabilidade. Sugere-se, tamb��m, criar uma estrutura s��lida e arejada para utilizar os n��o-tecidos impregnados em SAPs. Posteriormente, deve-se aplicar estas estruturas num sapato com a sola perfurada e test��-las no manequim t��rmico.

Welfare effects of entry into international markets with licensing

We study the effects of entry of a foreign firm on domestic welfare in the presence of licensing, when the entrant is technologically inferior to the incumbent. We show that foreign entry increases domestic welfare for intermediate (respectively, sufficiently large) technological differences between the firms under licensing with fixed fee (respectively, output royalty).

O empreendedorismo como op����o de (re)inser����o profissional

Este artigo procura evidenciar o empreendedorismo enquanto mecanismo de resposta �� (re)inser����o social, entendido enquanto necessidade ou oportunidade. Para al��m da apresenta����o do empreendedorsimo enquanto op����o individual, destaca-se o papel que as universidades e institutos polit��cnicos devem assumir no desenvolvimento do esp��rito empreendedor no cluster dos rec��m-licenciados.

BoaVista ��� Sensor Dedicado de Vis��o Artificial Baseado em Hardware (Re)configur��vel

4�� Festival Nacional de Rob��tica - Actas do Encontro Cient��fico - Proceedings of the Scientific Meeting, Biblioteca Almeida Garrett, Pal��cio de Cristal ��� Porto, 23-24 Abril 2004

Deixem que eu me (re)encontre

O presente relat��rio reflete um projeto de investiga����o no ��mbito do Mestrado em Educa����o e Interven����o Social, que assume como metodologia a Investiga����o A����o-Participativa, e que �� desenvolvido e constru��do com um grupo de pessoas desempregadas. Assim, e contando com os participantes como co-construtores de todo o processo, foi necess��rio elaborar uma an��lise e caracteriza����o da realidade da qual surgiram alguns problemas. �� com base neles que o projeto come��a a ser delineado, tendo por base a educa����o n��o-formal de adultos, e recorrendo a a����es e atividades para se alcan��arem os objetivos definidos e, desta forma, ser poss��vel compreender qual o impacto que ele teve na vida dos participantes. Denominado por ���Deixem que eu me (Re)Encontre���, este projeto de investiga����o pretendeu proporcionar momentos de desenvolvimento da autoestima, de redescoberta de capacidades e compet��ncias, e de cria����o de uma rede de suporte afetivo, estimulando nos participantes a apropria����o de um poder de interven����o, gerador de mudan��a nas suas vidas, que h�� muito se tinha perdido.

Re-Use Assessment of Thermoset Composite Wastes as Aggregate and Filler Replacement for��Concrete-Polymer Composite Materials: A case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

Sustainability Improvement of a composite materials��� industry through recycling and re-engineering process approaches

Recent Advances in Mechanics and Materials in Design