Showing papers by "University of Alicante published in 2001"
TL;DR: In this paper, the effect of different preparation variables on the final porous texture is discussed, such as KOH/anthracite ratio, heating rate, carbonization temperature and carbonization time.
683 citations
01 Jan 2001
TL;DR: In this article, three main layers of discourse-related sources of identity may be isolated: general, inherited attributes such as belonging to a community or to a specific sex or race.
Abstract: Human beings are inextricably tied to language, which plays a vital part in the shaping and placing of people within society. Broadly, three main layers of discourse-related sources of identity may be isolated. First, there are general, inherited attributes such as belonging to a community or to a specific sex or race. Second, there may be optional adherence to a certain group membership which on many occasions entails a faithful (and identity reinforcing) use of specific jargons or argots. Third, the person's own self is continuously shaped and developed through ordinary conversations with other people. These three general layers are far from permanent or stable features of discursive identity, but are subject to constant rearrangement. In this sense, one of the main sources of today's layer instability is networked communication among people from different countries (e.g., Internet), which produces sharp changes in the scope and influence of these layers.
499 citations
TL;DR: The authors analyzed the metaphorical conceptions of learning based on the reflections of 50 experienced teachers in an evening course on instructional psychology and found that the majority of these teachers shared traditional metaphors depicting teaching and learning as transmission of knowledge, followed by a smaller group of teachers expressing constructivist metaphors.
323 citations
TL;DR: This study analyzed the effects of S. tenacissima tussocks on the survival, growth, and ecophysiological features of experimentally planted seedlings of Medicago arborea, Quercus coccifera, and Pistacia lentiscus in three sites in a semiarid region in southeastern Spain.
Abstract: In arid and semiarid environments, isolated vegetative patches establish islands of fertility in which facilitation is a dominant interaction between plant species. These patches may provide favorable microsites for revegetation with desirable species in areas where traditional revegetation procedures fail. Alpha grass (Stipa tenacissima) steppes are widely distributed within the semiarid areas of southern Europe and northern Africa and represent a degraded stage of climax vegetation. In this study, we analyzed the effects of S. tenacissima tussocks on the survival, growth, and ecophysiological features of experimentally planted seedlings of Medicago arborea, Quercus coccifera, and Pistacia lentiscus in three sites in a semiarid region in southeastern Spain. Our main objective was to test whether S. tenacissima was able to facilitate shrub establishment in semiarid degraded steppes. Soils under S. tenacissima tussocks had higher organic matter content and water availability than those from open areas. Sti...
318 citations
TL;DR: The OO-method approach to Information Systems Modeling presented in this paper attempts to overcome the conventional (informal)/formal dichotomy by selecting the best ideas from both approaches.
225 citations
TL;DR: Semi-infinite programming (SIP) as discussed by the authors is an optimization problem in which finitely many variables appear in infinitely many constraints, and it naturally arises in an abundant number of applications in different fields of mathematics, economics and engineering.
213 citations
TL;DR: A comparative analysis of some classical solutions to bankruptcy problems from an axiomatic viewpoint is provided to facilitate the understanding of their differences and to clarify the type of situations in which each of these rules is better.
202 citations
TL;DR: Chrzanowski and Wieckowski as mentioned in this paper used spontaneous deposition to obtain a Pt/Ru catalyst with a packing density of up to 0.65 Ru atoms per Pt surface atom.
189 citations
TL;DR: In this article, the authors assess the microbial impact on both Altamira and Tito Bustillo Caves (northern Spain) and identify the identified damage including covering (scattered colored spots, whitish powdery patinas) of paintings by the microbial communities themselves and/or by their metabolic activity (including biofilms and 'bioinduced' precipitates).
Abstract: Host-rock, speleothems, and rock art paintings from Altamira and Tito Bustillo Caves (northern Spain) are coated by dense biofilms of phototrophic microorganisms (cyanobacteria and algae) and networks of heterotrophic bacteria (mainly actinomycetes). These microorganisms induce constructive (calcification, crystalline precipitates) and destructive fabrics (irregular etching, spiky calcite). To assess the microbial impact on both caves - which contain valuable rock art paintings - mineralogical, petrographical, hydrochemical, microenvironmental, and microbiological studies were carried out. The identified damage includes: (1) covering (scattered colored spots, whitish powdery patinas)of paintings by the microbial communities themselves and/or by their metabolic activity (including biofilms and 'bioinduced' precipitates); (2) chemical alteration, such as microbially mediated dissolution; and (3) mechanical alteration, such as substratum breakdown and scaling. In addition, some types of speleothems, such as ...
163 citations
TL;DR: This work consists of a review of kinetic models used for material decomposition, and also of the methods used for the analysis, and of the different models available for kinetic studies in thermobalance.
158 citations
TL;DR: In this paper, the authors evaluated the following hypotheses for the Region of Valencia (East Spain) based on these observations, and found that during the past three decades, climatic conditions have become more favourable for wildfires and high erosivity rainfall events.
TL;DR: A new axiomatization of the Shapley-Shubik and the Banzhaf power indices in the domain of simple superadditive games by means of transparent axioms is provided, and only one axiom differentiates the characterization of either index.
Abstract: We provide a new axiomatization of the Shapley-Shubik and the Banzhaf power indices in the domain of simple superadditive games by means of transparent axioms. Only anonymity is shared with the former characterizations in the literature. The rest of the axioms are substituted by more transparent ones in terms of power in collective decision-making procedures. In particular, a clear restatement and a weaker alternative for the transfer axiom are proposed. Only one axiom differentiates the characterization of either index, and these differentiating axioms provide a new point of comparison. In a first step both indices are characterized up to a zero and a unit of scale. Then both indices are singled out by simple normalizing axioms.
TL;DR: It is shown that independent preferences are globally stable in a large set of environments and locally stable in essentially any standard environment, provided that the number of subgroups that form in the society is large.
TL;DR: The purpose of this paper was to study the prevalence of nonstrabismic accommodative and binocular dysfunctions in a clinical population and to perform several tests to diagnose any form of refractive, accommodative or binocular dysfunction.
TL;DR: The electrochemical reduction of CO 2, which includes a number of different spe- cific approaches, may show promise as a means to help slow down the accumulation of this greenhouse gas in the atmosphere as mentioned in this paper.
Abstract: The electrochemical reduction of CO 2 , which includes a number of different spe- cific approaches, may show promise as a means to help slow down the accumulation of this greenhouse gas in the atmosphere. Two types of approaches are examined briefly here. First, CO 2 can be used as a reagent in the electrocarboxylation reaction to produce organic car- boxylic acids, for example, the pharmaceutical ibuprofen. Second, CO 2 can be converted to a fuel, either directly or via synthesis gas. The latter can be produced with reasonably good energy efficiency in a gas-diffusion, electrode-based cell even at present with existing elec- trocatalysts. Oxygen gas is produced as a by-product. Further work is needed to improve the selectivity and efficiency in this and other approaches.
TL;DR: In this article, an experimental salt weathering simulation and porous stone durability classification are proposed, which is a comparable study of weight loss and degradation of visual appearance due to salt crystallisation using, on the one hand, a standard durability test (UNE), and, in the other, the proposed durability test is comparable to the degradation of building stone.
TL;DR: Electrochemical method at laboratory scale for the treatment of biorefractory solutions with high phenol content--1000 ppm is described and the charge efficiency of COD removal was independent of the current density in the range studied (50-100 mA cm(-2).
01 Dec 2001
TL;DR: In this paper, the authors explored the following processes and studied how they confer buffering capacities to the seagrass ecosystem: (i) net autotrophy is persistent in Zostera noltii meadows where plant assimilation acts as a sink for nutrients.
Abstract: “Buffer capacities” has been defined in ecology as a holistic concept (e.g., Integration of Ecosystem Theories: A Pattern, second ed. Kluwer, Dordrecht, 1997, 388pp), but we show that it can also be worked out in mechanistic studies. Our mechanistic approach highlights that “buffering capacities” can be depleted progressively, and, therefore, we make a distinction between current and potential “buffering capacities”. We have applied this concept to understand the limited “local stability” in seagrass ecosystems and their vulnerability towards structural changes into macro-algal dominated communities. We explored the following processes and studied how they confer buffering capacities to the seagrass ecosystem: (i) net autotrophy is persistent in Zostera noltii meadows where plant assimilation acts as a sink for nutrients, this contrasted with the Ulva system that shifted back and forth between net autotrophy and net heterotrophy; (ii) the Z. noltii ecosystem possesses a certain albeit rather limited capacity to modify the balance between nitrogen fixation and denitrification, i.e., it was found that in situ nitrogen fixation always exceeded denitrification; (iii) the nitrogen demand of organoheterotrophic bacteria in the sediment results in nitrogen retention of N in the sediment and hence a buffer against release of nitrogen compounds from sediments, (iv) habitat diversification in seagrass meadows provides shelter for meiofauna and hence buffering against adverse conditions, (v) sedimentary iron provides a buffer against noxious sulfide (note: bacterial sulfide production is enhanced in anoxic sediment niches by increased organic matter loading). On the other hand, in the coastal system we studied, sedimentary iron appears less important as a redox-coupled buffer system against phosphate loading. This is because most inorganic phosphate is bound to calcium rather than to iron. In addition, our studies have highlighted the importance of plant–microbe interactions in the seagrass meadows.
TL;DR: In this paper, the pyrolysis and combustion of seven samples of sewage sludge were studied by TG dynamic runs carried out at 15°C min −1, and two different behaviors were observed.
TL;DR: In this paper, the global primary thermal decomposition of poly-(ethylene terephthalate) (PET) waste was studied in strict pyrolysis conditions and with different proportions of oxygen by TGA, between temperatures of 25 and 800°C.
TL;DR: In this paper, an ab initio method to study the electrical transport in nanocontacts is presented. But this method is based on traditional quantum-chemistry calculations and is not suitable for the measurement of the conductance of C.
Abstract: Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, Madrid 28049, Spain~Received 25 May 2001; published 24 August 2001!Building upon traditional quantum-chemistry calculations, we have implemented an ab initio method tostudy the electrical transport in nanocontacts We illustrate our technique calculating the conductance of C
TL;DR: The results show an extremely low diversity for the haloarchaea retrieved by cultivation even when modifications to the standard technique are introduced.
Abstract: The culturable haloarchaeal diversity in a crystallizer pond from a solar saltern has been analyzed and compared with the biodiversity directly retrieved by analysis of rRNA genes amplified from the environment. Two different sets of culture conditions have been assayed: solid medium with yeast extract as carbon source and liquid media with either yeast extract or a mixture of fishmeal, Spirulina sp., and Artemia salina. Seventeen colonies grown on plates with yeast extract incubated at 30°C were analyzed by 16S rDNA partial sequencing. Sixteen were closely related to haloarchaea of the genus Halorubrum; 13 of them to Halorubrum coriense, a haloarchaeon isolated from a solar saltern pond in Australia, which had not been previously isolated from the pond analyzed in this study; and one to Haloarcula marismortui. Liquid cultures were analyzed by ribosomal internal spacer analysis (RISA) and partial sequencing of the 16SrRNA genes. A total of 18 sequences were analyzed, 15 corresponding to RISA bands obtained from cultures, and 3 from the environmental sample used as inoculum. Thirteen sequences obtained from cultures were related to several Halorubrum species, and 2 to Haloarcula. One of the clones obtained directly from the environmental sample was distantly related to a Natronobacterium, whereas two were related to SPhT, the phylotype most frequently retrieved from this environment by culture independent techniques. Our results show an extremely low diversity for the haloarchaea retrieved by cultivation even when modifications to the standard technique are introduced.
TL;DR: In this paper, the main applications of immersion calorimetry in the study of microporous adsorbents such as activated carbons, including carbon molecular sieves, and microporic zeolites are reviewed.
TL;DR: In this paper, the authors present a new traning in PEPTIDE COUPLING REAGENTS, which is an extension of the Peptide Compensated Coupling this paper.
TL;DR: In this article, four commercially available coal tar pitches have been characterised through the combination of conventional techniques used for pitch characterisation, like elemental analysis and solvent fractionation, and infrared spectroscopy (FTIR) and thermal analysis (thermogravimetry (TG)-differential thermal analysis).
TL;DR: In this article, three different apparatus, a thermobalance, a pyroprobe and a laboratory furnace, were used to study the kinetics of decomposition and the evolution of gas and volatiles.
TL;DR: In this paper, the synthesis of distillation column configurations to separate non-azeotropic multicomponent mixtures containing N components is addressed, for sharp separations of an N-component mixture.
Abstract: This paper addresses the synthesis of distillation column configurations to separate non-azeotropic multicomponent mixtures containing N components. It is shown that, for sharp separations of an N-...
TL;DR: Minicolumn tests showed that the performance of highly activated carbon fibers is around 7 times better than the commercial GAC (with surface area at around 1100 m2/g), whereas carbon fibers with medium activation degree had a removal efficiency worse than thecommercial carbon.
TL;DR: In this article, deformation structures in Tortonian turbiditic deposits of the Guadix Basin (southern Spain) have been described and interpreted as the result of liquefaction and/or fluidization processes triggered by the rapid sedimentation of single high concentration turbidites.
Abstract: Soft-sediment deformation structures in Tortonian turbiditic deposits of the Guadix Basin (southern Spain) have been described. The most common structures are asymmetrical pillow structures and elongated sets of loadcasts. The structures are metric in scale and have been interpreted as the result of liquefaction and/or fluidization processes triggered by the rapid sedimentation of single high concentration turbidites. Final morphology of soft-sediment deformation structures is related to two main driving force systems: unstable density gradient and lateral shear stress. The latter is probably induced by the downslope component of the sediment weight. The asymmetry of deformational structures (in horizontal and vertical cross-section) allows a clarification of the relationship between morphology of deformation and direction of lateral shear stress: this relationship seems ambiguous and confused in the literature. The interpretations both of deformation mechanism and trigger agent have been supported with:-field analyses;-calculations on the liquefaction processes induced by rapid sedimentation;-qualitative models in laboratory.
TL;DR: In this article, the mechanism of SO 2 oxidation by O 2 on ACs and ACFs has been studied over a wide variety of samples with different porosity and surface oxygen content.