Leak Detection in a Branched System by Inverse Transient Analysis with the Admittance Matrix Method

The diagnosis of water distribution systems by means of the inverse transient analysis requires efficient and reliable numerical models. In the network admittance matrix method (NAMM) the 1-D waterhammer governing equations are integrated in the frequency domain and organized in a laplacian matrix form. The NAMM is particularly suitable for complex systems because of this structure and can be used for the system diagnosis, including leak sizing and location. In this paper a damaged branched system is considered and the diagnosis is performed by means of the NAMM using experimental data from laboratory transient tests. Two different boundary conditions are used in the implementation of the NAMM and the leak is located and sized with a reasonable approximation. An extended numerical investigation is also presented and allows confirmation of the results for different leak locations. The use of the NAMM for the leak detection and the validation using experimental data on a branched system are the main original contributions of this work. The successful diagnosis indicates promising results for applications in more complex systems.     

Identification of the unobservable behaviour of industrial automation systems by Petri nets

This paper addresses the problem of identifying the model of the unobservable behaviour of discrete event systems in the industrial automation sector. Assuming that the fault-free system structure and dynamics are known, the paper proposes an algorithm that monitors the system on-line, storing the occurred observable event sequence and the corresponding reached states. At each event observation, the algorithm checks whether some unobservable events have occurred on the basis of the knowledge of the Petri net (PN) modelling the nominal system behaviour and the knowledge of the current PN marking. By defining and solving some integer linear programming problems, the algorithm decides whether it is necessary to introduce some unobservable (silent) transitions in the PN model and provides a PN structure that is consistent with the observed event string. A case study describing an industrial automation system shows the efficiency and the applicability of the proposed algorithm.     

Solvable Set/Hyperset Contexts: II. A Goal-Driven Unification Algorithm for the Blended Case

A universe composed by rational ground terms is characterized, both constructively and axiomatically, where the interpreted construct with which designates the operation of adjoining one element to a set, coexists with free Herbrand functors. Ordinary syntactic equivalence must be superseded by a bisimilarity relation ≈, between trees labeled over a signature, that suitably reflects the semantics of with. Membership (definable as “d∈t =_Def (t with d≈t”) meets the non-well-foundedness property characteristic of hyperset theory A goal-driven algorithm for solving the corresponding unification problem is provided, it is proved to be totally correct, and exploited to show that the problem itself is NP-complete. The results are then extended to the treatment of the operator less, designating the one-element removal operation. Applications to the automaton matching and type-finding problems are illustrated. Received: March 4, 1996; revised version: August 24, 1998     

Mu and Delta Opioid Receptor Targeting Reduces Connexin 43-Based Heterocellular Coupling during Neuropathic Pain

Chronic neuropathic pain emerges from either central or peripheral lesions inducing spontaneous or amplified responses to non-noxious stimuli. Despite different pharmacological approaches to treat such a chronic disease, neuropathic pain still represents an unmet clinical need, due to long-term therapeutic regimens and severe side effects that limit application of currently available drugs. A critical phenomenon involved in central sensitization is the exchange of signalling molecules and cytokines, between glia and neurons, driving the chronicization process. Herein, using a chronic constriction injury (CCI) model of neuropathic pain, we evaluated the efficacy of the mu (M-) and delta (D-) opioid receptor (-OR) targeting agent LP2 in modulating connexin-based heterocellular coupling and cytokine levels. We found that long-term efficacy of LP2 is consequent to MOR-DOR targeting resulting in the reduction of CCI-induced astrocyte-to-microglia heterocellular coupling mediated by connexin 43. We also found that single targeting of DOR reduces TNF and IL-6 levels in the chronic phase of the disease, but the peripheral and central discharge as the primary source of excitotoxic stimulation in the spinal cord requires a simultaneous MOR-DOR targeting to reduce CCI-induced neuropathic pain.     

The Inactivation Mechanism of Human Group IIA Phospholipase A2 by Scalaradial

Secretory phospholipases A₂ (sPLA₂s) are implicated in the pathogenesis of several inflammation diseases, such as rheumatoid arthritis, septic shock, psoriasis, and asthma. Thus, an understanding of their inactivation mechanisms could be useful for the development of new classes of chemical selective inhibitors. In the marine environment, several bioactive terpenoids possess interesting anti‐inflammatory activity, often through covalent and/or noncovalent inactivation of sPLA₂. Herein, we report the molecular mechanism of human group IIA phospholipase A₂ (sPLA₂‐IIA) inactivation by Scalaradial (SLD), a marine 1,4‐dialdehyde terpenoid isolated from the sponge Cacospongia mollior and endowed with a significant anti‐inflammatory profile. Our results have been collected by a combination of biochemical approaches, advanced mass spectrometry, surface plasmon resonance, and molecular modeling. These suggest that SLD acts as a competitive inhibitor. Indeed, the sPLA₂‐IIA inactivation process seems to be driven by the noncovalent recognition process of SLD in the enzyme active site and by chelation of the catalytic calcium ion. In contrast, covalent modification of the enzyme by the SLD dialdehyde moiety emerges as only a minor side event in the ligand–enzyme interaction. These results could be helpful for the rational design of new PLA₂ inhibitors that would be able to selectively target the enzyme active site.     

Blue fish burgers: nutritional characterisation and sensory optimisation

In order to reduce waste of marine resources, valorise fishing discards and move towards fish consumption, a new ready-to-cook seafood product was developed. In particular, a chemical investigation on chub mackerel and hake was conducted to the aim of mixing the two fish species to produce nutritionally balanced fish burgers. In addition, to evaluate consumer opinion about these new fresh products and best acceptability of different proportions of mackerel and hake, focus group interviews and consumer test were also performed. The results of the chemical analyses achieved on both selected fish species gave rise to minimally processed fish products with a high amount of chub mackerel, therefore providing the desired nutritional properties and low level of hake in order to obtain firmer and wetter burgers. By means of focus group interviews, the novelty and high level of convenience of the developed fresh commodity was highlighted. Consumer test declared that the most successful sample was that with 70% chub mackerel and 30% hake.     

Fabrication of GM3-Enriched Sphingomyelin/Cholesterol Solid-Supported Lipid Membranes on Au/SiO2 Plasmonic Substrates

The fabrication of solid-supported artificial lipid bilayers enriched with biological agents is an important step for acquiring more insights into their behavior from in vitro studies. In this work we demonstrate the formation of lipid artificial membranes enriched with ganglioside GM3, whose role in the cell proliferation and tumor angiogenesis is still an object of extensive investigation. The membranes are formed by fusion of small unilamellar vesicles (SUV) obtained from the sonication of multi-lamellar vesicles (MLV) formed from a hydrated mixture of GM3, brain sphingomyelin and cholesterol. The effective formation of SUV was confirmed by Dynamic light scattering (DLS) measurements. The recognition of the ganglioside in the biomimetic raft like biomembranes is accomplished via surface plasmon resonance (SPR) by exploiting the ganglioside affinity with wheat germ agglutinin (WGA). The affinity constant of the binding between the inglobated GM3 and WGA has been measured for three different GM3 molar concentrations. Beside the effective generation of GM3-enriched biomimetic membranes, our results indicate a decrease in the apparent WGA–GM3 dissociation constant at increasing GM3 concentrations up to 20 mol%, consistent with clustering effects of the ganglioside in the fabricated biomembranes.     

Extraction of metals from automotive shredder residue:Preliminary results of different leaching systems

The study is focused on the extraction of valuable metals from automotive shredder residue (ASR) by different leaching solutions. First, ASR samples were roasted at 600 °C to simulate a thermal treatme...     

The impact of ICT on intermodal transportation systems: A modelling approach by Petri nets

The paper addresses the issues of modelling and managing Intermodal Transportation Systems (ITS) at the operational level, considering the impact of the new Information and Communication Technologies (ICT). ITS are regarded as discrete event systems and are modelled in a timed Petri net framework. In order to show the efficiency of the ITS modelling and controlling technique, the case study of the ferry terminal of Trieste (Italy) is considered. The results show that the approach can be employed to verify the potential of ICT for efficient real time management of ITS, and their impact on the ITS infrastructures.