Monte Carlo determination of the critical coupling in ϕ24\phi^4_2 theory

We use lattice formulation of $\phi^4$ theory in order to investigate non--perturbative features of its continuum limit in two dimensions. In particular, by means of Monte Carlo calculations, we obtain the critical coupling constant $g/\mu^2$ in the continuum, where $g$ is the {\em unrenormalised} coupling. Our final result is $g/\mu^2=11.15(6)(3)$.Comment: Version published on Phys. Rev. D. We added a reference and modified a couple of sentence

Activated biochars used as adsorbents for dyes removal

Adsorption represents one of the most interesting technique for the removal of pollutants from wastewaters. Activated carbons show the best performances on this kind of processes but their high production costs limit their applications. In this context a big challenge is to find new materials having characteristic similar to those of commercial activated carbons but being environmental friendly and cheaper. In this work the adsorption efficiency of activated biochars produced from pine wood was investigated on the removal of dyes from water. An innovative method for the activation of the biochar using deep eutectic solvents (DES) was tuned and the characteristics of the obtained adsorbent material were compared with those of biochar activated with traditional method and non-activated biochar. The best adsorption capacities were obtained with the DES activated biochar, reaching a value of 480 mg/g for the methylene blue adsorption. Adsorption isotherm and kinetic models were applied to experimental data in order to understand the adsorption mechanism of the process

Biomass gasification plant and syngas clean-up system

Gasification is recognized as one of the most promising technologies to convert low quality fuels into more valuable ones. The principal problem related with the use of biomass in gasification processes is the high amount of tar released during the pyrolysis step. It is thus necessary to recover tar and to transform it in lighter combustible gas species such as CH4, CO and H-2. In this work the experimental results of a medium industrial scale plant fed with olive husk and having a capacity of 250 kWt are presented. The gasifier is composed by a up-draft reactor which is followed by a secondary fixed bed reactor filled with alluminium oxide spheres having high porosity dedicated to the tar conversion reactions. The syngas is then used to feed an internal combustion engine with a production of 60 kWe

Methane dry reforming over nickel perovsikite catalysts

In recent years dry reforming of methane (DRM) has received considerable attention as a promising alternative to steam reforming for synthesis gas (H2 and CO) production. This process could be industrially advantageous, yielding a syngas with a H2/CO ratio close to 1, suitable for Fischer-Tropsch synthesis to liquid hydrocarbons and for production of valuable oxygenated chemicals. The major drawback of the process is the endothermicity of the reaction that implies the use of a suitable catalyst to work at relatively low temperatures (923-1,023 K). Higher temperatures would make the process unaffordable for an industrial development and would increase the risk of undesirable side reactions, such as coke formation, that are the main causes of catalyst deactivation. In this work the activity of nickel perovskite catalysts were studied and the results were compared with rhodium perovskite. It is well known that rhodium is very active and stable for dry reforming but its high cost makes its utilization limited. The Ni, due to its low cost, is a promising substitute even if it is more susceptible to coking. The perovskite structure allows a high dispersion of the metal into the catalyst increasing the catalytic activity. In this work the Ni perovskite was obtained with two methods (auto-combustion and modified citrate methods). The results pointed out that the Ni perovskite obtained with the auto-combustion method is a promising route for the use of Ni in this process. The experimental tests show that with Ni catalyst very good activity can be achieved from temperature of 973 K

Liberate the form. White concrete in the work of Álvaro Siza

[EN] The study of the extensive work of Álvaro Siza Vieira allows us to relate the progressive linguistic innovation and spatial experimentation of his architecture with the use of diff erent construction techniques and technologies. Assuming the colour white as the guiding thread of the discourse, it traces Siza’s professional career from his initial link with the Portuguese architectural tradition of the early 20th century to his current adoption of the constructive principles of fair-faced concrete. The contribution puts some of the Portuguese master’s recent works into perspective, ordering and analysing the projects with the aim of elucidating the architectural principles underlying the use of exposed white concrete. A progressive quest to liberate form, in which concrete acts as an ideal material, increasing the creative and expressive possibilities of architecture.[ES] El estudio de la extensa obra de Álvaro Siza Viera permite relacionar la progresiva innovación lingüística y la experimentación espacial de su arquitectura con el uso de diferentes técnicas y tecnologías constructivas. Asumiendo el color blanco como hilo conductor del discurso, se recorre la trayectoria profesional de Siza desde su inicial vínculo con la tradición arquitectónica portuguesa de principios del siglo XX, hasta la actual adopción de los principios constructivo del hormigón visto. La contribución pone en perspectiva algunas recientes obras del maestro portugués, ordenando y analizando los proyectos con el objetivo de deducir los principios arquitectónicos subyacentes al empleo del hormigón blanco visto. Una progresiva búsqueda para liberar la forma, en la cual el hormigón actúa como un material ideal, aumentando las posibilidades creativas y expresivas de la arquitectura.De Marco, P. (2022). Liberar la forma. El hormigón blanco en la obra de Álvaro Siza. En CIAB 10. X Congreso internacional arquitectura blanca. Editorial Universitat Politècnica de València. 252-263. https://doi.org/10.4995/CIAB10.2022.13999OCS25226

‘HOSPITALITY’ AND INNOVATION. HOW AN INNOVATION IN THE I.S. HUMAN RESOURCES MANAGEMENT AND COMMUNICATION APPROACH CAN HELP CHANGE THE ICT MANAGEMENT APPROACH: THE “BANCO” CASE IN THE OUTSOURCING SUPPLY SERVICES

The paper presents and discusses a case which shows the possibility of employing the results of theoretical research (namely some of the concepts elaborated by Claudio Ciborra in his “The Labyrinths of Information”) in changing human resources management and development, in fostering organizational learning, and in building an ICT management coherent with business goals. BAnCO (194 employees) is a supplier of outsourced ICT services for Italian regional and interregional banks which changed its ‘netsourcing’ business model (services rendered to a consortium of small client-owner banks of the ICT supplying company) to an ‘enterprise partnership’ business model, based on servicing both the client investors and external customers. To support the change in strategy, at the end of 1999 it launched a program that deeply innovated performance management (substituting the appraisal based on absolute judgment rating scales to one based on action plans), training activities (traditional classroom work was integrated by personalized, diffused learning centered on the evaluation of the competence requirements of roles), and communication and knowledge management (key competences were defined and up-dated through interaction between in-house experts and outside experts in the ICT and banking fields). The three main sections of the paper are devoted: (i) to illustrate the theoretical background explaining both Ciborra’s approach and the traits that in his view characterize an effectively managed organization dealing with ICT; (ii) to describe in depth the main areas addressed by the BAnCO program, how project work was conducted, and the outputs produced; (iii) to discuss the case and to comment on the results obtained. In sum, far from being a ‘model’ or a ‘guide’, Ciborra’s outlook seems to carry helpful “operational” indications when looking for ways to change business-as-usual for more effective and dynamic conducts

La ville en tant que jardin. Éléments d' une utopie

[EN] From ancient myths to religious metaphors, the history of civilisation tells of numerous gardens admirable for their physical characteristics and underlying symbolic values. These gardens are not mere recreational spaces, but places of human life in all its complexity, thus representing the ideal combination of city and vegetation, man and nature. In the 20th century, some research and projects have attempted to create alternatives to current cities based - in different ways - on the ancient ideal of the garden.With the advent of urbanization of the world population, recent urban policies demonstrate possible strategies to change the destiny of the city by introducing nature into public space. Furthermore, from the study of some contemporary experiences it is possible to recognise traces of an innovative organic approach to design, the possibility of spatial coherence and the architecture-nature interdependence necessary for the construction of an effective ecosystem. A new architectural-urban paradigm, a holistic and interscalar vision that, finally, faces a truly sustainable horizon.[CA] Des dels mites antics fins a les metàfores religioses, la història de la civilització parla de nombrosos jardins admirables per les seues característiques físiques i valors simbòlics subjacents. Aquests jardins no són mers espais d’esbarjo, sinó llocs de la vida humana en tota la seua complexitat, representant llavors la combinació ideal de ciutat i vegetació, home i naturalesa. En el segle XX algunes investigacions i projectes han tractat de materialitzar alternatives a les ciutats actuals basades ―de diferents maneres― en l’antic ideal del jardí. Enfront de la nova emergència d’urbanització de la població mundial, recents polítiques urbanes demostren possibles estratègies per a canviar el destí de la ciutat mitjançant la introducció de la naturalesa en l’espai públic. A més, a partir de l’estudi d’algunes experiències contemporànies és possible reconéixer petjades d’un innovador enfocament orgànic al disseny, la possibilitat d’una coherència espacial i la interdependència arquitectura-naturalesa necessària per a la construcció d’un efectiu ecosistema. Un nou paradigma arquitectònic-urbà, una visió holística i interescalar que, finalment, s’enfronte a un horitzó realment sostenible.[ES] Desde los mitos antiguos hasta las metáforas religiosas, la historia de la civilización habla de numerosos jardines admirables por sus características físicas y valores simbólicos subyacentes. Estos jardines no son meros espacios de recreo, sino lugares de la vida humana en toda su complexidad, representando entonces la combinación ideal de ciudad y vegetación, hombre y naturaleza. En el siglo XX algunas investigaciones y proyectos han tratado de materializar alternativas a las ciudades actuales basadas - de diferentes maneras - en el antiguo ideal del jardín.Frente a la nueva emergencia de urbanización de la población mundial, recientes políticas urbanas demuestran posibles estrategias para cambiar el destino de la ciudad mediante la introducción de la naturaleza en el espacio publico. Además, a partir del estudio de algunas experiencias contemporáneas es posible reconocer huellas de un innovador enfoque orgánico al diseño, la posibilidad de una coherencia espacial y la interdependencia arquitectura-naturaleza necesaria para la construcción de un efectivo ecosistema. Un nuevo paradigma arquitectónico-urbano, una visión holística e interescalar que, finalmente, se enfrente a un horizonte realmente sostenible.[FR] Depuis les mythes anciens jusqu' aux métaphores religieuses, l' histoire de la civilisation parle de nombreux jardins admirables à cause de leurs caractéristiques physiques et valeurs symboliques sous-jacentes. Ces jardins-là ne sont pas de simples espaces de détente, mais des endroits de la vie humaine dans toute sa complexité, représentant alors la combinaison idéale de ville et de végétation, d' homme et de nature. Pendant le XXe siècle, certains projets et recherches ont essayé de matérialiser des alternatives aux villes actuelles fondées -de différentes façons- sur l ancien idéal du jardin. Face à la nouvelle émergence d' urbanisation de la population mondiale, quelques politiques urbaines récentes montrent des possibles stratégies en vue de changer le destin de la ville moyennant l' introduction de la nature dans l' espace publique. D' ailleurs, à partir de l' étude de certaines expériences contemporaines, il est possible de reconnaître les traces d' une approche organique novatrice de dessin, ainsi que la possibilité d' une cohérence spatiale et d' une interdépendance architecture-nature nécessaire pour la construction d' un écosystème effectif. Voilà un nouveau paradigme architectural-urbain, une vision holistique et intercalaire qui, finalement, puisse faire face à un horizon réellement durable.De Marco, P. (2023). La ciutat com a jardí. Elements d' una utopia. ANUARI d Arquitectura i Societat. (3):68-97. https://doi.org/10.4995/anuari.2023.196536897

Influence of the catalyst support on the steam reforming performance of toluene as tar model compound

The large amount of tar produced along with the syngas during biomass gasification is one of the major obstacle for the diffusion of gasifiers at industrial scale. Catalytic cracking and reforming are the most suitable processes for the transformation of tar into lighter gases. The selection of suitable catalysts is a critical step. The catalysts must own high activity and high resistance to deactivation for coke deposition. In this work the effect of two different supports, mayenite and aluminium oxide, on the activity of the nickel was investigated in the steam reforming of toluene that was used as tar model compound. In particular, the performed experimentations aimed to test the mayenite in terms of improvement of resistance to carbon deposition in conditions similar to those of gasification reactors. The obtained results indicate that Ni /mayenite catalyst needs higher temperature to activate and leads to lower value of toluene conversion with respect to Ni / alumina. However, mayenite, which is known from literature to have higher resistance to coke deposition due to the presence of free oxygens in the lattice which oxidize the coke deposited on the catalyst surface showed higher resistance to deactivation especially for low steam to carbon ratios