In this paper, we analyze a linearized model for incompressible transversely isotropic dispersive fiber-reinforced materials in which both the elastic and dispersive properties depend on the direction of the fibers. We investigate the motions in bodies made of these materials that are subjected to prescribed shear or normal action on part of the rigid boundaries. In the case where the motion is induced by shear stresses acting at the boundary, we provide the analytical solution for the displacement field from which we derive the components of the stress tensor. In the case where the motion is due to the action of normal stresses at the boundary, the initial and boundary value problem is solved using a projection algorithm based on spectral methods. In both cases, we quantify how anisotropic dispersion and material stiffness affect the displacement field.
This study presents an integrated sustainability assessment, covering environmental performance and economic feasibility, of an innovative vertical haloponic system designed for the co-production of Penaeus vannamei shrimp and salt-tolerant crops (in this case study, Salicornia). Primary data were used for the growth phase of Salicornia and shrimp, electricity and water consumption, and the vertical structures. Environmental performance was assessed in accordance with ISO 14040/44 standards using the ReCiPe Midpoint/Endpoint methodology. Results indicate that electricity consumption is the dominant environmental hotspot across nearly all impact categories, particularly for the midpoint categories of climate change (95,244.52 kg CO2 eq), fossil resource scarcity (30,772.74 kg oil eq), and water consumption (3756.36 m3). Infrastructure materials, especially steel and plastics, are the second-largest contributors, primarily affecting toxicity and mineral resource depletion. Feed and nutrient solutions have moderate but non-negligible impacts, while sludge valorization through vermicomposting yields limited environmental credits. The endpoint results confirm and amplify the patterns identified at the midpoint level. LCC results suggest potential profitability under the modeled baseline conditions, although high initial investments and operational costs remain critical constraints. In particular, at the more conservative discount rate, a Net Present Value (NPV) of €51,619.12 was obtained, with a payback period of 5 years. Overall, the system shows potential as a sustainable food production model, provided that technological optimization and energy transition strategies are implemented.
Modelling argumentative dialogue in multi-agent systems requires capturing both the evolution of an underlying argumentative structure and the way individual agents maintain and revise their own positions during interaction. We present a concurrent language for modelling argumentative dialogue over a shared Bipolar Argumentation Framework, integrating an explicit representation of agents’ commitments and refusals. We define a set of speech acts that regulate dialogue progression, governing the introduction of arguments, their interrelations, and agents’ endorsement or exclusion of them. We also provide an operational semantics for the language, in which dialogue moves update the shared framework together with agents’ commitment and refusal states in a coherent manner. As a case study, we show how to model service contract negotiation scenarios, where arguments correspond to service requests, contractual obligations, permissions, and violations discussed among interacting agents.
