137262 research outputs found
Sort by
Sensor-integrated TPU soft actuators fabricated by foam additive manufacturing
No full textThe development of multifunctional soft devices requires materials that combine compliance with integrated sensing, yet most existing solutions rely on rigid sensors or on conductive filaments where anisotropic filler networks and infill-based porosity limit reproducibility. Previous work on foamed PLA has shown density reduction via additive manufacturing, but without functional integration, while conventional conductive TPU remains confined to bulk or patterned infill structures with poor electromechanical consistency. Here we present the first demonstration of Foam Additive Manufacturing (FAM) applied to carbon-black-filled thermoplastic polyurethane (TPU) for the fabrication of lightweight, sensor-integrated soft actuators. By tuning solubilization, desorption, and extrusion conditions, we generate homogeneous microcellular foams with up to 42.2% density reduction while preserving mechanical integrity. The resulting conductive foams exhibit stable and repeatable piezoresistive responses under load. Comparative tests on phalanx- and finger-like specimens confirm enhanced compliance and real-time resistance feedback during grasping and release, outperforming both bulk and infill-matched references. This work establishes FAM as a new route to directly print soft actuators that integrate structure and sensing in a single material, overcoming the anisotropy and scalability limits of previous foamed PLA and conductive TPU approaches. Potential applications span soft robotics, prosthetics, and wearable systems
Carbon nanoparticle aggregates on films produced via electric field-assisted flame synthesis
No full textThe flame synthesis of carbon nanoparticle (CNP) films is a promising approach for fabricating advanced nanomaterials. This study investigates the compositional and optical properties of CNPs collected using electric field-assisted thermophoretic deposition in a laminar premixed ethylene-air flame. CNPs were sampled on substrates at varying electric potentials (0 kV, −2 kV, −3 kV) and subsequently characterized to assess the influence of the electric field on their features.
CNPs were dissolved in N-methyl-pyrrolidone to obtain stable suspensions of primary aggregates to be analyzed via UV–Visible absorption, fluorescence spectroscopy, and size exclusion chromatography. Results indicate that the application of an electric field alters the size distribution of the CNPs, promoting the formation of aggregates with lower optical band gaps while the fraction of smaller CNPs (<20 nm) diminished.
The in-depth analysis allows a comprehensive understanding of the size-dependent effects of electric fields on flame-formed CNPs. It was shown that the electric field not only enhances the deposition rate as reported in previous works but also impacts the compositional, optical and structural properties of the resulting films, favouring smaller particles aggregation and influencing the morphology of the primary aggregates with promising implications for applications requiring conductive and/or optically active carbon materials
«Castra», «domus», «palatia», porte in età federiciana: un sistema complesso dai molti significati
No full textThe article analyzes the castle system of the age of Frederick II of Hohenstaufen. Through the examination of selected exemplary palaces or castles, it redefines the meaning of castrum, palatium, and, in particular, domus, which often denotes a “building structure” in its own right, as there were sometimes several within the same edifice. Special attention is devoted to the symbolic meaning of certain constructions that embody representations of Frederick II’s political ideology: the Gate of Capua and a palace in Naples described by the chronicler Francesco Pipino
Seismic analysis of a zoned earth dam after decades of operation
No full textThe seismic safety assessment of zoned earth dams that have been in operation for several decades requires a preliminary evaluation of their pre-seismic behavior through the interpretation of monitoring data and laboratory tests on construction materials, collected throughout the dam's service life. Once it is verified whether any factors have influenced the dam's performance and whether this behavior remains consistent with the original design expectations, the seismic response can be analyzed using either pseudo-dynamic (Newmark-based) or coupled elastoplastic continuum approaches. The most relevant damage mechanisms are those affecting watertightness. Zoned earth dams may develop seismic-induced fractures resulting from sliding through the core or from stress release associated with distributed deformation. Coupled analyses provide fundamental physical insight into the processes governing hydraulic fracturing under both seismic and post-seismic conditions, while pseudo-dynamic methods offer valuable information on potential sliding mechanisms and on whether failure surfaces are likely to propagate through the core. The integration of these two approaches enables a deeper understanding of core vulnerability and improves the overall reliability of seismic safety evaluations. This study explores these aspects through the analysis of the Conza Dam in Italy—a unique case where a major earthquake occurred during construction, and where comparative testing of original and recent materials revealed progressive changes in properties over decades of operation. The combined application of pseudodynamic and coupled dynamic analyses to this case demonstrates their complementarity and effectiveness in predicting potential earthquake-induced damage
Undoing the migrant-citizen binomial: reimagining the boundaries of citizenship through acts of solidarity in a southern European City during the COVID-19 pandemic
No full textThe COVID-19 pandemic contributed to making national borders more visible and less permeable, reasserting the centrality of citizenship “as the ultimate marker of belonging and solidarity”, and reaffirming the distinction between citizens and non-citizens. In this context, citizenship and national belonging functioned as rigid categories for determining entitlement to protection and assistance. Many states failed to guarantee social rights to all residents, leading to forms of exclusion, particularly for non-citizens. Simultaneously, the crisis sparked the emergence of new forms of civic engagement and solidarity “from below,” enacted by civil society to fill the void left “from above.” Volunteerism flourished supporting those facing food insecurity, evictions, and economic hardship. In some cases, immigrants themselves became central protagonists of these initiatives. This paper contributes to debates on inclusive citizenship and solidarity by jointly analyzing the concepts of citizenship from below and solidarity from below, applying them to a case study of grassroots practices promoted by migrants and citizens in the city of Naples (Italy) during the pandemic. Drawing on long term ethnographic research, it examines how, through the creation of transversal alliances and mutual aid networks, these actors responded to systemic exclusion and economic marginality. Special attention is given to two intertwined pathways: migrant-led initiatives such as the S.E.E.D.S. project, and actions embedded in the urban commons (beni comuni), self-managed civic spaces that became material and symbolic infrastructures of proximity and care. Both trajectories fostered inclusive solidarity capable of contesting institutional boundaries and reimagining belonging. The paper shows how these practices reframed citizenship, challenging, and renewing how participants defined and enacted their civic roles through social relations. The analysis extends the theory of acts of citizenship by demonstrating how social and political participation during crisis—particularly by migrant actors—produced new grammars of recognition and belonging. These findings encourage a rethinking of solidarity, alliances, membership, borders, and citizenship in more inclusive and dynamic terms
Sacred and “Archetypal Images”. Religion and New Forms of Spirituality in Postmodern Society
No full textThe hypothesis underlying this article is that the social relationship with the sacred in postmodern Western society revolves around (at least) two juxtaposed polarities of the imagery: the Christian religion (especially Catholic), on the one hand, pertains to a “diurnal order” in which the transcendence of God – however weakened – still guarantees and imposes a division between the worldly and the otherworldly; the relationship with the sacred of new forms of spirituality, on the other hand, originates and ends on the immanent level, hence a certain degree of “undifferentiation” that refers to a “nocturnal order” (Durand, 1999). These polarities of the imagery are shaped by different “myths”. The first – the one underlying Christianity – is characterized by a predominant “aerial” symbolism, while the second by an “aquatic” one (new forms of spirituality).
However, in postmodern society, we witness a process of symbolic disarticulation, because the “‘archetypal images’” (Jacobi, 2004, p. 61) reveal themselves as ‘blurred’ to the consciousness. Likewise, this phenomenon produced a hiatus between meanings and experience: hence, dialectically, the meanings given to experience are also ‘blurred’. This is due to the collapse of “ambivalence”, which is instead the main feature of the “archetypal images” released by all the elements (Bachelard, 2005).
It follows that it is very hard for individuals socialized within these peculiar imageries to live a “full” experience of the sacred: this domain has traditionally ‘contained’ the “dramas” of existence, by revealing its “universal” meaning to the “total consciousness of human being” (Eliade, 2009b, p. 134). Today, it no longer seems to be the case.
This paper aims to scrutinize the above-mentioned social changes through the analytical perspective of depth sociology and sociology of imagery
Enhanced Low-Temperature Ozone-Assisted Catalytic Oxidation of Propane Over Cu–Mn Bimetallic Oxides
No full textLiquid carriers are expected to play a pivotal role in the large-scale transport of hydrogen. Among the various candidates, ammonia emerges as a carbon-free molecule, supported by mature, cost-effective infrastructure. In decentralized electrical power generation, ammonia storage can be integrated directly with fuel cells or indirectly via cracking and separation units to feed proton exchange membrane fuel cells. The overall energy efficiency of such integrated systems is strongly influenced by the interaction between the unit operations and the potential to couple exothermic and endothermic processes for energy recovery. This review analyzes recent developments in ammonia-based systems integrated with fuel cells, focusing on the characteristics and interaction of key units from an integration and performance perspective. Critical gaps are identified that currently limit system efficiency and deployment. Particular attention is devoted to nitrogen and ammonia separation, which significantly affects fuel cell performance and overall system efficiency depending on the fuel cell type and operating conditions. Integration with afterburners and gas turbines is discussed as a strategy to enhance overall energy output. Finally, the review addresses electrification opportunities and safety concerns, highlighting potential hazards, accidental scenarios, and mitigation strategies to support the safe and sustainable design of decentralized ammonia-based power systems
On second–order determination of the constitutive constants of an hyperelastic dielectric
No full textElectro-active polymers, particularly dielectric elastomers, for their rapid and reversible electromechanical response,
exhibit great potential for the next-generation of soft actuators. In this paper, we describe a methodology for determining
the second-order constitutive constants of a homogeneous, isotropic, and hyperelastic dielectric material that can
be applied to compressible and incompressible dielectrics. A Lagrangian framework is employed to address the
quasi-electroelastostatic problem, with a detailed comparison of free energy formulations proposed in literature for
compressible and incompressible hyperelastic dielectrics. An analytical solution is derived for a controllable state in a
simple geometry, and a new experimental setup is introduced to take into account boundary layer effects produced by
the electric field. This setup could be used as a basic device to design experimental procedures for determining the
material’s constitutive constants
The role of community in historical center development plans and in regenerating heritage. A case in Naples metropolitan area
No full textThe role of crystal-bubble interactions, outgassing and magma composition in the ascent dynamics of alkaline magmas: Implications for eruptions at Vesuvius
No full textIntermediate to evolved alkaline magmas (phono-tephritic, tephri-phonolitic and phonolitic) exhibit a wide range in eruptive style and have produced some of the most catastrophic eruptions in human history, such as the 79 AD Plinian eruption of Vesuvius (Italy). However, eruptive dynamics are driven by complex, non-linear conduit processes during magma ascent, requiring a holistic approach to investigate their influence on explosivity. This study integrates synchrotron radiation X-ray computed microtomography (SRμCT) with a 1D steady-state conduit model, to investigate how crystal-bubble interactions, pre-eruptive conditions, outgassing, and magma composition affect eruptive style at alkaline volcanic systems, using Vesuvius as a case study. We analyse pyroclasts from the 79 AD Plinian and 1944 lava-fountaining eruptions using SRμCT. Our SRμCT results reveal that heterogeneous bubble nucleation can be promoted further by leucite crystals, contributing to the high bubble number densities (>104 mm−3) observed in Plinian products. Despite high bubble connectivity, low throatpore size ratios (the ratio between the radii of the throat and connected vesicles) and elevated tortuosity restrict gas–melt separation during fast magma ascent, promoting fragmentation. Numerical simulations reveal tephri-phonolitic and phonolitic magmas are prone to fragmentation across diverse conditions, producing highly explosive eruptions. Only relatively high temperatures (>1050 oC) and low bubble number densities (102 to 103 mm-3) can promote lava flow and fountaining activity. Instead, phono-tephritic magmas exhibit highly explosive eruptions at considerably lower temperatures (<950 oC). Temperature controls magma viscosity, influencing the ascent rate and the outgassing efficiency, which, in turn, affects conduit dynamics and the eruptive behaviour. Our findings highlight that for alkaline systems, the parameter space which is conducive to highly explosive eruptions expands as the magma composition evolves and its viscosity increases. These insights enhance our understanding of eruption mechanisms, providing critical insights for assessing volcanic hazard and emergency planning at alkaline volcanic systems