Systems, Autopoietic

Definition The authors’ definition of the autopoietic system has evolved through the years. One of them states that an autopoietic system is organized (defined as a unity) as a network of processes of production (transformation and destruction) of components that produces the components which: (1) through their interactions and transformations regenerate and realize the network of processes (relations) that produced them; and (2) constitute it (the machine) as a concrete unity in the space in which they exist by specifying the topological domain of its realization as such a network (Varela 1979, p. 13). Nearly the same formula was earlier used to define an autopoietic machine (Maturana and Varela 1973/1980, 1984/1987, p. 135

Steam curing effect on the properties of fly ash high performance recycled aggregates concrete

The aim of this study is to encourage the use of Recycled Concrete Aggregate (RCA) in High Performance Concrete (HPC) with fly ash. Three types of coarse RCA sourced from medium to high strength concretes were employed in 100% replacement. In order to boost their mechanical performance at early age, steam curing was assessed. The physical, mechanical and durability properties of Recycled Aggregate Concretes (RAC) were compared to those from Natural Aggregate Concrete (NAC). According to the results, natural aggregates could be completely replaced by RCA if they are sourced from similar parent HPC. Lower quality RCAs decreased the mechanical and durability behavior of HPC. However, the properties of RAC had higher long-term improvements than those from NAC due to the influence of fly ash. Despite steam curing produced higher early-age compressive strength, it had longterm negative effects. Nevertheless, RACs were less affected by long term effects of steam curing.Postprint (published version

Properties of plain concrete produced employing recycled aggregates and sea water

The final publication is available at Springer via http://dx.doi.org/10.1007/s40999-017-0229-0The generation of construction and demolition waste (C&DW) is a noteworthy environmental and economic concern. The development of new applications in which Recycled Mixed Aggregates (RMA) can be used will lead to a reduction of landfills growth. Moreover, the use of seawater shall represent another advance in sustainability due to the consequent reduction of fresh water consumption, which can be a limited resource in certain areas. Although seawater is not generally recommended for concrete production, especially in reinforced concretes, seawater could be a viable replacement for fresh water in the production of plain concretes. This study intends to analyse the possibility of using RMA and seawater in the production of concrete to be used in port sites. This study is based on three different parameters: cement class, water source and RMA content. The results highlighted the beneficial effects of using type III cement, especially with regard to durability properties. The concretes produced employing RMA and type III cement achieved lower value of sorptivity coefficient and higher values of ultrasonic pulse velocity (UPV), chloride ion penetration resistance and electrical resistivity than those produced with natural aggregates and type I cement. Moreover, the use of seawater in concretes with type III cement not only produced higher density and lower absorption capacity but also higher mechanical properties by creating a denser cement matrix, which proved to suffer low decrease by RMA addition.Peer ReviewedPostprint (author's final draft

Overview of Basque quantificational elements

This paper explores the various syntactic and morphological means that Basque language makes use of to express quantification.Artikulu honek euskarak kuantifikazioa adierazteko dituen baliabide sintaktiko zein morfologikoak ditu aztergai

Euskal artikuluak bultza ditzakeen interpretazioez

International audienc

Influence of the quality of recycled aggregates on the mechanical and durability properties of high performance concrete

The final publication is available at Springer via http://dx.doi.org/10.1007/s12649-016-9637-7The main objective of this experimental work is to analyse the effect of recycled aggregates (RA), on the basis of the study of the various qualities, of the physical, mechanical and durability properties of high performance concrete (HPC). Five types of recycled aggregates: three coarse RA sourced from parent concretes of 100, 60 and 40 MPa, as well as one coarse mixed recycled aggregate and one fine ceramic waste aggregate were used as replacement for natural aggregates (NA). Two types of coarse NA and two types of river sands were employed for concrete production. On the basis of the findings of our research it was determined that the reduction in quality and the increase in the amount of RA substitution produced a decline in the properties of HPC. According to our analysis of the mechanical properties, a 100 % replacement of coarse NA for recycled concrete aggregates can be employed, providing the RA has been sourced from a 60 MPa minimum-strength concrete. Nevertheless, durability behaviour was greatly influenced by the use of RA, and consequently replacement ratios of high quality RA should be reduced to 50 % to achieve similar behaviour patterns to those of NA concrete. Moreover, severe reductions of RA qualities (sourced from 40 MPa strength concretes or mixed waste) only permitted 20 % replacement ratios on HPC production. However, those concretes containing fine ceramic RA (up to 30 %) reached higher compressive strength, higher chloride-ion penetration resistance and higher improvements of durability properties at longer ages than those concretes produced using NA concrete.Peer ReviewedPostprint (author's final draft

The way the definite determiner affects quantifiers in Basque

Based on Basque data (and in line with Etxeberria & Giannakidou 2010, to appear), this paper argues that the domain for quantifiers in certain languages is restricted overtly by a definite determiner (D). This strategy of domain restriction via D--DDR--happens by applying DDR to the nominal argument, but DDR can also apply to the Q-det itself, in which case it forms a constituent with it. In both cases, DDR is a type preserving function, i.e. a modifier, and supplies the contextual C variable. This analysis provides support for the program that domain restriction is syntactically realized, but an important refinement is proposed: domain restriction can affect the Q-det itself (pace Stanley 2002), and in fact quite systematically in certain languages. The Qdet that is affected by DDR is typically a strong one. So-called weak quantifiers cannot be contextually restricted by DDR. Crucially in Basque, D only appears with strong quantifiers

Structural behaviour of prestressed concrete sleepers produced with high performance recycled aggregate concrete

The final publication is available at Springer via http://dx.doi.org/10.1617/s11527-016-0966-6A comparative analysis of the structural behaviour of prestressed concrete sleepers made with high performance concrete (HPC) and high performance recycled aggregate concrete (HPRAC) is presented in this study. Two types of HPRAC sleepers were tested, using 50 and 100% of recycled concrete aggregate (RCA) in replacement of coarse natural aggregates. The RCA employed in this research was sourced from crushing rejected HPC sleepers. The aim of this study was to determine through analysis if the HPRAC sleepers’ behaviour fulfilled the European minimum requirements standards for prestressed concrete sleepers and compare their experimental behaviour with that of the HPC sleepers. The three types of prestressed concrete sleepers were subjected to static load tests at rail-seat and centre section (positive and negative load). In the centre section tests a comparative study between the experimental results and the proposed values of four assessment methods of ultimate capacity was carried out. Dynamic load and fatigue tests were also performed at the rail-seat section. The HPRACs and HPC sleepers met all the structural requirements for prestressed concrete sleepers. The experimental results determined the satisfactory performance of the HPRAC-50 and the HPRAC-100, which was very similar to that of the HPC sleepers. The load–strain behaviour recorded via the use of strain gauges on the prestressing bars revealed slightly higher stiffness of the HPC sleepers. The values obtained from the four assessment methods of ultimate capacity were also accurate when applied to HPRAC.Peer ReviewedPostprint (author's final draft

D-heads, domain restriction, and variation: from Greek and Basque to St'at'imcets Salish

In joint work (Giannakidou 2004, Etxeberria 2005, Etxeberria and Giannakidou 2010), we argue that one of the functions a D head can perform in language is to provide domain restriction. For this, we propose a new mode of composition for D--DDR. DDR is a type-shifting of D from its "regular" individual yielding function (iota) to a modifier function supplying the context set variable C. In Greek, St'át'imcets Salish, and Basque we find DDR applying to Q, but in St'át'imcets, the D-head shifts to DDR also when it combines with the NP under Q. Our analysis relies on Salish D being a definiteness head, since C is a discourse salient or familiar property; we thus challenge Matthewson's (1998, 2001) treatment of St'át'imcets Salish D as indefinite. Our goal here is to consider the St'át'imcets data and show that (a) the arguments for indefiniteness of D are not conclusive, and (b) the St'át'imcets facts are fully consistent with an analysis of DDR as a manifestation of definiteness. The St'át'imcets D, we will suggest, is best analyzed as a deictic, demonstrative-like D head, consistent with its morphology

The way the definite determiner affects quantifiers in Basque

Based on Basque data (and in line with Etxeberria & Giannakidou 2010, to appear), this paper argues that the domain for quantifiers in certain languages is restricted overtly by a definite determiner (D). This strategy of domain restriction via D--DDR--happens by applying DDR to the nominal argument, but DDR can also apply to the Q-det itself, in which case it forms a constituent with it. In both cases, DDR is a type preserving function, i.e. a modifier, and supplies the contextual C variable. This analysis provides support for the program that domain restriction is syntactically realized, but an important refinement is proposed: domain restriction can affect the Q-det itself (pace Stanley 2002), and in fact quite systematically in certain languages. The Qdet that is affected by DDR is typically a strong one. So-called weak quantifiers cannot be contextually restricted by DDR. Crucially in Basque, D only appears with strong quantifiers