This paper introduces the topological finiteness condition finite derivation type (FDT) on the class of semigroups. This notion is naturally extended from the monoid case. With this new concept we are able to prove that if a Rees matrix semigroup M[S;I,J;P] has FDT then the semigroup S also has FDT. Given a monoid S and a finitely presented Rees matrix semigroup M[S;I,J;P] we prove that if the ideal of S generated by the entries of P has FDT, then so does M[S;I,J;P]. In particular, we show that, for a finitely presented completely simple semigroup M, the Rees matrix semigroup M=M[S;I,J;P] has FDT if and only if the group S has FDT.

In a global market, companies must deal with a high rate of changes in business environment. Most manufacturing systems fail to sustain productivity when process disturbances occur. Therefore, it is necessary to create resilient production systems with the ability to return, rapidly, to the initial stage or to an improved one. The parameters, variables and restrictions of the production system are inherently vagueness. This situation suggests that there are dependencies between relevant variables which are not possible to know with precision. The fuzzy logic theory has the ability to describe, in a quantitative and qualitative way, problems that involve vagueness and imprecision. This paper provides an overview for the use of fuzzy logic to establish resilient production systems. Fuzzy concepts are reviewed, in particular its applications to production systems, trying to classify related fuzzy parameters and vari-ables. In addition, the concept of resilient systems are reviewed and extended to production. Finally, it is proposed an approach to establish resilient production systems using the fuzzy set theory

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Late Jurassic theropod dinosaurs have been known in Portugal since 1863 but only now are they being fully understood, with the recognition of genera such as Allosaurus, Aviatyrannis, Ceratosaurus, Lourinhanosaurus, and Torvosaurus from the Lourinhã and Alcobaça Formations (Kimmeridgian/Tithonian). Ceratosaurus dentisulcatus can now be reported from Portugal. It represents the only occurrence of this species outside the Morrison Formation.
New cranial elements confirm the presence of Torvosaurus tanneri, in Portugal. Torvosaurus was the largest Late Jurassic land carnivore. New postcranial and cranial elements allow the erection of a new species from Portugal, Allosaurus europaeus n.sp. The theropod assemblage of Portugal is similar to that of the Morrison Formation.

This paper is mainly focused on the characterisation of a glass material (GM) obtained from the thermal treatment of a bottom ash (BA) produced at the Municipal Solid Waste (MSW) incineration plant of Valorsul. By melting the BA at 1400ºC during 2 hours, and without using any chemical additives, a homogeneous black-coloured glass was obtained. The thermal and mechanical properties of this glass were characterised. The thermal expansion coefficient, measured by dilatometry, was 9-10 x 10-6 per ºC and the modulus of rupture, determined by four-point bending test, was 75±6 MPa, which are similar values to those exhibited by commercial soda-lime-silica glasses used in structural applications. The chemical and the ecotoxicological leaching behaviour of the GM were also analysed. The GM was submitted to a leaching procedure composed of 15 sequential extraction cycles. A liquid/solid (L/S) ratio of 2 l/kg was applied in each cycle. The leachates were filtered through a membrane of PTFE (porosity: 0.45 8m). The filtered leachates were characterised for different chemical parameters and for an ecotoxicological indicator (bacterium Vibrio fischeri). The GM was also submitted to a microwave acidic digestion for the assessment of the total metal content. The crude BA was also submitted to the same experimental procedures. The GM showed levels of chemical emission and ecotoxicity for V. fischeri much lower than those determined for the crude BA. Similar characterisation studies will be pursued with the glass-ceramics produced by adequate thermal treatment of the glass, in order to investigate the effect of the crystallization on the final properties.

The vertical stability of anchored concrete soldier-pile walls is highly influenced by the complexity of the interaction between the different parts of the structure, i.e., wall, anchors, and supported soil mass. The problem is analyzed using upper bound limit analysis through published solutions and proposed closed-form equations. A comparison is made between these equations and numerical limit analyses. An estimate of the theoretical minimum pile resistance required to avoid excavation collapse is presented. Published finite element elastoplastic results are used for comparison.Key words: anchored retaining wall, concrete soldier-pile walls, vertical equilibrium, finite elements, limit analysis, soil-to-wall interface shear forces.

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