Hidden potentialities

The search for “complexity signatures” in natural laws is a main concern for researchers working in many different fields, going from physics to biology. Very simple laws are able to produce unforeseen behaviors, and from their “simplicity” sometimes it is not possible to predict anything about the potential complexities they are able to produce when applied to random initial conditions. Here elementary cellular automata (ECA) are used to illustrate this idea. In fact, using a recently developed approach to establish a correspondence between ECA rules and logical functions that constitute their structure (logical spectra) we analyzed ECA groups represented by automata 120 and 164. The automaton governed by rule 120 generates complex patterns under certain random initial conditions, whereas the one corresponding to rule 164 is known as a simple law when it is evaluated at random initial conditions. However, slight changes in the initial conditions of both ECA produce dramatic “simplicity–complexity transitions”, as it is shown here. These examples show that complexity, even in very simple formal systems, results from a subtle interplay between the structure of the laws and the initial conditions. Moreover, they draw attention to the importance of investigating if analogous comportments hold in large-scale natural phenomena as the yet enigmatic genotype–phenotype mapping.     

The evaluation of a social adaptive website for cultural events

In this paper, we present an evaluation of a social adaptive website in the domain of cultural events, iCITY DSA, which provides information about cultural resources and events that promote the cultural heritage in the city of Turin. Using this evaluation, our objective was to investigate the actual usage of a social adaptive website, in an effort to discover the real behavior of users, the unforeseen correlations among user actions and the consequent interactive behavior, the accuracy of both system and social recommendations and their impact on the users themselves, and the role of tagging in the user modeling process. The major contributions of the paper are manifold: insights into user interactions with social adaptive systems; guidelines for future designs; evaluation of the tagging activity and tag meanings in relation to the application domain and thus their impact on the representation of the user model; and a demonstration of how a combination and interplay of evaluation methodologies (e.g., quantitative and qualitative) can enhance our comprehension of evaluation data.     

Multitemporal thermal analysis to detect moisture on a building façade

It is well known that the content of water does affect materials behaviour and may cause important damages to buildings, including structural deterioration. Thermography is a non-intrusive imaging technique that allows the inspection of different materials based on their surface temperatures. Within an appropriate thermal analysis, moisture and other structural damages can be detected. The present research work deals with multitemporal thermal analysis to detect moisture on buildings, as well as other alterations. Two different approaches are tested to determine the effectiveness on the moisture surveys, one simple based on image differences, and another more sophisticated based on principal components analysis (PCA). The results are tested at the front door of the Arenberg Castle (Leuven, Belgium). Some moisture maps are derived and used to determine the reliability of either the computation of image differences or the PCA to carry out semi-automatically moisture surveys on architectural façades. The latter method is proven to be superior when using thermal imagery acquired at different times.     

Ultra dispersed particles of Fe(III) compounds in the strongly basic crosslinked ionic polymer-precursors for new sorbents and catalysts

The Mössbauer spectroscopy and SEM investigation shows that crosslinked ionic polymers containing strongly basic functional groups adsorb Fe(III)-containing cations from sulphate solution through the formation in the polymer phase of high dispersed particles of jarosite mineral type compounds. Using different procedures the particles sizes and morphology, their repartition on the surface and in the volume of the polymer granule, the composition of the “polymer-inorganic compound” structural units were modified that is important for sorbents and catalysts obtaining. On heating in water medium in a boiling water bath, a part of the jarosite type compounds in the polymer phase is converted into ultra fine β-FeOOH particles in superparamagnetic state and the rest, in relatively massive and magnetically ordered β-FeOOH particles. The higher is the content of the Fe(III) in the polymer phase, the shorter is the duration of heating in water for the appearance of relatively massive particles of β-FeOOH. The particles of the jarosite type compounds and of the β-FeOOH are formed both on the surface and in the volume of the polymer granule. Upon heating in water, a part of the Fe(III)-containing particles have migrated from the volume of the polymer granule to the surface. Thermogravimetric investigation (in an N₂ atmosphere) shows that on heating of the Fe(III)-containing polymer sample up to 900 °C, complicated processes take place.     

Synthesis of crystalline metal nitride and metal carbide nanostructures by sol–gel chemistry

Attention toward nanosized metal nitrides and carbides is rapidly increasing thanks to their chemical characteristics that make them as valid and sustainable alternatives to noble metals in catalysis and to air-sensitive metals or oxides for applications under harsh conditions. They are mostly used as bulk phase or micron sized powders, due to an intrinsic difficulty to synthesize them as nanoparticles in a systematic and scalable fashion. However, nanosized metal nitrides and carbides could exhibit improved performances, e.g. in catalysis due to a higher surface area, and can be shaped more easily than corresponding larger grains for further specific applications. Recently, sol–gel chemistry has closed this gap and now enables the simple, cheap, and sustainable production of metal nitride and carbide nanoparticles.In the present review we give an overview on recent sol–gel based pathways for the synthesis of metal nitride and carbide nanoparticles, believing that a better knowledge of the potentialities of these still hardly touched materials stimulates research interest and applications.     

Multifunctional biomagnetic capsules for easy removal of phenol and bisphenol A

This paper reports fabrication, optimization and characterization of multifunctional biocapsules with immobilized enzyme using a layer-by-layer configuration and their application for removal of phenol and bisphenol A (BPA). The method is based on the combined use of enzymatic oxidation of the BPA and subsequent binding of the reaction product onto a chitosan core biopolymer. This platform has multiple functions including: (1) enzymatic degradation of BPA, (2) adsorption of the degraded compound within the core material, (3) colorimetric quantification and (4) magnetic capabilities. We examined various configurations of core/shell structures of alginate and chitosan and determined the stability and the optimum conditions in which these structures provide the most effective removal capacity. The amount of BPA that can be removed per capsule is 5.6 ppm while phenol can be removed up to 10 ppm per capsule within 15 h.     

Efficiency convergence processes and effects of regulation in the nonspecialized retail sector in Spain

This work analyzes the effects of the regulation/deregulation processes carried out on the evolution of efficiency in Spanish retail-sector firms in the period 1996–2004. The results suggest that the regulation in this sector has had a considerable influence on firms’ efficiency, in particular, the legislation on the expansion of commercial opening hours after 2000. The results provide clear evidence of a convergence in firms’ efficiency from the initial year considered to superior levels. Moreover, the pattern of convergence differs in function of the region in which the firm operates. The evolution of efficiency given by the means of different groups of regulation intensity levels through the time seems to show clearly in the groups of high and low regulation. It is observed that the group of high regulation is the most efficient. The analysis of the firms as a whole confirms the convergence process. Considering the analysis for subperiods an improvement is observed for all regions in the period 2000 at 2004.     

Making friends in online games: gender differences and designing for greater social connectedness

ABSTRACT

While online multiplayer games provide an opportunity for players to both maintain and establish new connections, male and female players have been found to experience these environments differently. Interviews (n?=?22) and focus groups (n?=?14) were used to explore these differences as they impact on creating new social connections, as well as to provide recommendations for the development of new social tools and features that account for these differences. While all participants experienced toxicity and performance pressure as barriers to forming new connections, female players uniquely reported the impacts of misogynistic targeting and stereotype threat. In turn, female players wishing to avoid these stresses would often mask their gender. The common practice of gender misrepresentation by both male and female players impacted female players’ ability to create social connections through voice technology, as well as building their distrust of unknown others. Recommendations are made to build social connectedness between players taking into account the specific constraints faced by female players. These include establishing mentoring opportunities as well as profiling players beyond their immediate skill or rank. Additionally, the desire for control of one’s online identity presents practical challenges that may be overcome through thoughtful design.     

Multistage treatment system for raw leachate from sanitary landfill combining biological nitrification–denitrification/solar photo-Fenton/biological processes,at a scale close to industrial – Biodegradability enhancement and evolution profile of trace pollutants

A multistage treatment system, at a scale close to the industrial, was designed for the treatment of a mature raw landfill leachate, including: a) an activated sludge biological oxidation (ASBO), under aerobic and anoxic conditions; b) a solar photo-Fenton process, enhancing the bio-treated leachate biodegradability, with and without sludge removal after acidification; and c) a final polishing step, with further ASBO.