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Coralligenous (C) is a type of Open Frame Reef, characterized by a variable association of calcareous red algae and macroinvertebrates. It is distributed across the Mediterranean shelf below the deepest seagrass meadows and down to the mesophotic zone, with different facies. The Italian project FISR “CRESCIBLUREEF” provided an extraordinary opportunity to explore the development of the Mediterranean C, from inception to present-day morphology and distribution off the SE coasts of Sicily. The spatial extension of C hybrid banks and discrete reliefs over the studied Sicilian shelf controls the hydrodynamics at the seafloor, the habitat biodiversity, and the related carbonate production at the shelf scale. The analyzed C samples, collected at about 36 m depth, had a columnar shape, were Holocene in age, and their development significantly modified the seafloor geomorphology. Our observations confirmed that most of the framework was built by calcareous red algae with an important contribution by bryozoans, with serpulids, molluscs, and rare corals as accompanying components of the sessile macroscopic fauna.The framework was highly porous, with a primary porosity derived from the growth, shape and structure of the skeletal components of both builders and dwellers, and an important secondary porosity derived from bioerosion and other early taphonomic processes involving both skeletonised and soft-bodied organisms, like sponges. During the entire process of framework growth and development, sponges played an important role as mineralization mediators of the autochthonous micrite fraction, which contributes significantly to the framework consolidation. Detrital micrite, rich in fine skeletal remains, is trapped in the primary and secondary cavities and represents an archive for the study of the organisms which are not directly involved in the framework building.

Coralligenous (C) includes calcareous build-ups of biogenic origin, formed since the Holocene transgression. Peculiar columnar-shaped C outcrops were documented offshore Marzamemi village (SE Sicily, Ionian Sea), although the actual extension and distribution were not assessed. Project ‘CRESCIBLUREEF’ produced a new, 17 km2 high-resolution bathymetric map, leading to good knowledge about their extent in this area. C bioconstructions are largely distributed along two depth ranges 36–42 m and 86–102 m water depth. By coupling the documented uplift rate in this region and the Holocene sea-level curve, we were able to interpret the distribution of C outcrops over terraces. However, additional investigation is required to understand: (1) the role of the inherited continental shelf landscape, in creating a favorable substrate for the settlement and growth of C habitats during the Holocene, and (2) the extent to which C bioconstructions can impact the evolution of present-day continental shelf landforms and landscapes.

A major challenge in the field of Augmented Reality (AR) is the way in which augmented information is presented in a wide range of uncontrollable environmental conditions. In fact, the variability of colours and illumination conditions of the real environment makes it difficult to choose the most suitable appearance properties for augmented contents. In many AR applications, the colours of virtual objects play a crucial role in blending digital information into the real environment, therefore these colours should be selected according to the appearance of the real background. In some use cases, the colours of virtual objects need to be harmonised with the ones of the real environment; in other cases, the colours should be chosen to ensure the visibility (e.g. maximizing the contrast) of the augmented data with respect to the background. To this end, the paper presents a background-aware colourisation technique that allows for selecting virtual objects’ colours in accordance with the real environment in real-time. Given an arbitrary real background, virtual objects’ colours are automatically chosen according to three different strategies, i.e. harmonic, disharmonic, and balanced. The proposed AR colourisation technique was assessed with a user study that focused on three different case studies. The results were promising and suggest the potential of the proposed technique for many different application areas. In particular, disharmonic and balanced strategies ensured the distinctiveness of virtual objects according to the real background. Instead, the harmonic strategy was less effective in the case of colourful complex AR scenarios.

Coralligenous (C) bioconstructions include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean Sea. These peculiar habitats thrive from shallow waters (15-20 m of water depth (w.d.) up to the limit of the mesophotic zone, and they formed since the Holocene transgression. They are from few to tens of meters large, displaying variable lateral continuity and thickness. Peculiar C outcrops are present offshore Marzamemi (southeastern Sicily, Ionian Sea). Their extension and distribution across the shelf were investigated within the project CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs. We produced a new 17 km2 high-resolution bathymetric map using a R2-Sonic 2022 system, ground-truthed by ROV video inspections. From a geomorphological point of view, the shelf is typified by four distinct marine terraces. Climate change and tectonic uplift are the dominant forcing mechanisms responsible for the formation of long and narrow terraced landforms in a variety of geomorphic settings; and marine terraces are largely used to reconstruct the Quaternary glacial and interglacial climates. The coupling of documented uplift rate in this region (ca. 0.2 mm/yr since the Tyrrhenian time) and the evidence reported in literature for late Quaternary relative sea-level curves shows a good correlation between the distribution of C outcrops and local, short stasis of sea level transgression periods, culminated with the rapid Flandrian transgression. C outcrops are mainly spread over the first and last terraces at two specific depth ranges: from 36 to 42 m of w.d., and from 86 to 102 m of w.d., respectively. Settlement and growth were mainly favored by a low sedimentation regime. Indeed, lowstand stages were likely characterized by erosional forces. This is particularly noticeable in the middle of our study area, where we have a paleo-incision typified by peculiar erosional features we were able to map. The role of the inherited continental shelf landscape in creating favorable substrate for the settlement and growth of C during the Holocene is here investigated.

The use of modeling and ergonomic analysis software is a widespread practice in the industrial sector to effectively improve the operator’s well-being and operating comfort within the workplace. In this context, the paper proposes a Mixed Reality system for the ergonomic assessment of industrial workstations. Specifically, the proposed system integrates motion capture tools, a head-mounted display device, and ergonomic analysis software to simulate and analyse the operations to be carried out within a virtual workplace where some physical components, with which the operator interact, are prototyped through 3D printing technology in order to make the simulation as realistic as possible. The proposed Mixed Reality system in fact increases the realism of the simulation and improves the effectiveness of the ergonomics analysis thanks to the haptic feedback that the user perceives when manipulating the physical objects.

The advent of Additive Manufacturing (AM) is uncovering the limits of the current CAD systems and, at the same time, is highlighting the potentials of the Topology Optimization (TO) and Generative Design (GD) tools that had not been fully exploited until now. Differently from the traditional design approach in which designers occupy a predominant role in each stage of the design process, the introduction of such tools in the product development process pushes toward simulation-driven design approaches which imply a significant change in the role of the designer. To this end, the paper presents a comparison of two different design methods for Additive Manufacturing based on the adoption of TO and GD tools. The comparison aims to offer a reflection on the evolution of the traditional approach when TO and GD tools are used, and to highlight the potential and limitations of these optimization tools when adopted in an integrated manner with the CAD systems. Furthermore, this comparative study can be a useful and practical source for designers to identify the most appropriate approach to adopt based on their needs and project resources. The comparative study is carried out through the design study of a prototype of a rocker arm and a brake pedal for the Formula Student race car. Their results, compared in terms of mechanical performances, show that both TO and especially GD tools can be efficiently adopted early in a design process oriented to AM to redesign components to make them lighter and stronger.

Purpose The purpose of this study is to investigate the feasibility of using additive manufacturing (AM) technique to produce an efficient valve manifold for hydraulic actuator by redesigning valve blocks produced by conventional methods. Design/methodology/approach A priori, a computational fluid dynamics (CFD) analysis was carried out using the software ANSYS Fluent to determine the optimal flow path that results in least pressure drop, highest average velocity and least energy losses. Fluid–structure interaction (FSI) simulations, processed with imported pressure distribution from the CFD, were conducted to determine the resulting loading and deformations of the manifold assembly. Findings The new design offers a 23 per cent reduction of oil volume in the circuit, while weighing 84 per cent less. When using the new design, a decrease of pressure drop by nearly 25 per cent and an increase in the average velocity by 2.5 per cent is achieved. A good agreement, within 16 per cent, is found in terms of the pressure drop between the experiment and computational model. Originality/value It is possible to build an efficient hydraulic manifold design by iterative refinement for adequate production via selective laser melting (SLM) and minimize used material to circumventing building support structures in non-machinable features of the manifold.

Augmented Reality (AR) is one of the nine key technologies of Industry 4.0 and one of the most promising innovation accelerators that in the next years will bring smart factories to a higher level of efficiency. In this context, the paper presents an AR tool that improves and increases the efficiency of data collection and exchange of information among different professional figures involved in the design and production processes of products for the oil and gas sector. In fact, prototyping and labour-intensive activities usually require modifications and improvements to be made on-site that should be sent as feedback to the technical office. To this end, the proposed AR tool supports workers at the workplace to easily detect and annotate design variations made during their working activities and furthermore to formalize and automate the collecting and transferring of this data to the designers in order to prevent loss of information. Field experimentation has been carried out with end-users to evaluate their acceptance by means usability studies, based on objective and subjective metrics, and personal interviews. Experimental results show that the proposed AR tool provides medium-to-high levels of usability and has been positively accepted by all the participants involved in the study.

Hybrid manufacturing is a new production strategy based on the combination of various processes to manufacture components more efficiently in terms of quality, productivity, and/or sustainability. Combinations of subtractive, forming, and additive manufacturing processes can follow one another to produce the desired parts. Hence, both part complexity and performance can increase significantly. The highlighted strategy has been tested by considering two different processes that are typically utilised for small batches of customised parts. Specifically, selective laser sintering has been used to thicken sheets locally, which are subsequently formed by single point incremental forming. This process combination can result in the development of a rapid prototyping technique that exploits the peculiarities of both the utilised processes, and thus allows for the manufacturing of more complex and/or higher quality parts, in a more flexible manner. In the research herein reported, various solutions have been tested to analyse the impact of the proposed hybrid manufacturing strategy on the a) dimensional accuracy, in terms of deviation from the nominal shape, b) quality, in terms of thickness distribution, and c) part complexity, in terms of the obtainable three-dimensional shape, of stainless-steel-formed sheets.

This work proposes an approach to fabricate micro patterned surfaces on PA2200 polyamide in order to improve its performance in terms of wettability and adhesion. In more detail, the present work aims to change the wettability of the surface and decrease their bacteria adhesion tendency. The experimental procedure consists of imprinting a set of different micro patterned structures over the polymer in order to verify the effectiveness of the methodology to change the contact angle of the surface, and in turn, reduce the occurrence of bacteria adhesion. Four different surface patterning were produced by laser ablation of a commercially pure titanium alloy, and then imprinted over the polyamide by surface stamping. The resulting surfaces were analyzed by topographical characterization and scanning electron microscopy. The wettability was probed by contact angle measurements while the bacteria adhesion was analyzed by adhesion test. The experimental results demonstrate the effectiveness of the method to modify the surface characteristics and to obtain a reliable patterned surface without using chemical hazardous material, opening to the possibility to replicate more complex structures and to obtain graded engineering surfaces.

Autonomous Surface Vehicles are versatile marine vehicles that allow to fulfill a variety of offshore activities. Their versatility has been appreciated by the marine and aquatic science community, in fact, in the last years, a large number of ASVs have been developed in research projects and introduced in the market.

Underwater manipulation is a key technology for marine industries and exploration that can be efficiently adopted in other application fields, such as underwater archaeology, biological manipulation, scientific expedition, as well as offshore construction in the Oil and Gas industry. It is performed remotely by expert pilots thanks to the visual feedbacks provided by one or more cameras but without any information about the distance between the end-effector and the target. To this end, the paper presents a novel system based on a sensorized robotic arm, stereoscopic 3D perception and augmented reality visualization to support ROV's pilots in underwater manipulation tasks. The system, thanks to the adoption of an optical-stereo camera, provides a visual feedback of the underwater scene on which a depth map of the underwater workspace is augmented on. In particular, combining the kinematics of the robotic arm and the standard photogrammetric model of the stereo camera, it is possible to generate a depth map that shows to the pilots the distances of the surface of the scene objects from the end-effector's pose. Experimental tests carried out in the context of the CoMAS (In-situ conservation planning of Underwater Archaeological Artefacts) project have demonstrated the effectiveness of the proposed system.

Underwater exploration, in the last years, has evolved toward a wide adoption of increasingly smaller ROVs (Remotely Operated Vehicle). As a consequence, the need to equip these underwater vehicles with robotic arms is currently rising as well. According to this demand, the paper presents three innovative solutions achieved in the UVMS (Underwater Vehicle-Manipulator System) field. Firstly, the paper proposes a modular architecture for a lightweight underwater robotic arm, which can be mounted on small-sized ROVs. The modular concept of the arm enables several different configurations, each one characterized by the related DOFs, deployed according to the type of application to be performed. Secondly, the arm has been equipped with an adaptive gripper that, taking advantage of the additive manufacturing techniques, is able to easily grip differently shaped objects. Lastly, the underwater arm is controlled through a Master–Slave approach, designed for commercial off-the-shelf electronics, that on the one hand, entailed a significant reduction of the bill of materials, but, on the other hand, required a greater effort in the software development. Experimental tests have been carried out to measure and evaluate the gripping and manipulation capability of the robotic arm and the performance of the proposed control system.