Optimization of Customized Industrial Pneumatic Nozzle to Reduce Noise Emissions

This study proposes a customized industrial nozzle for generating impulsive air jets. It is installed on an automatic machine where wine caps are stacked and shot consecutively into a rotating cyl-inder by an air jet. This process is very noisy; hence, this study aimed to investigate possible geo-metric variations of the nozzle that can reduce the emitted noise. First, the nozzle was tested in a laboratory to measure the air consumption at different supply pressures. Subsequently, 3D models of the nozzle and its variations were created and used for computational fluid dynamics simula-tions. Different boundary conditions were set, first to validate the model and compare it with the experimental test results, and then to simulate the real working conditions and determine the geometry that is less noisy while maintaining the velocity peak. Among the various possibilities, shortening the final ducts of the nozzle appears to be the most promising solution. These modified nozzles could be easily added to current machines to provide immediate benefits, and this study represents a promising start for action on other machines where this type of device is present

Semidiscrete Modeling of Systems of Wedge Disclinations and Edge Dislocations via the Airy Stress Function Method

We present a variational theory for lattice defects of rotational and translational type. We focus on finite systems of planar wedge disclinations, disclination dipoles, and edge dislocations, which we model as the solutions to minimum problems for isotropic elastic energies under the constraint of kinematic incompatibility. Operating under the assumption of planar linearized kinematics, we formulate the mechanical equilibrium problem in terms of the Airy stress function, for which we introduce a rigorous analytical formulation in the context of incompatible elasticity. Our main result entails the analysis of the energetic equivalence of systems of disclination dipoles and edge dislocations in the asymptotics of their singular limit regimes. By adopting the regularization approach via core radius, we show that, as the core radius vanishes, the asymptotic energy expansion for disclination dipoles coincides with the energy of finite systems of edge dislocations. This proves that Eshelby's kinematic characterization of an edge dislocation in terms of a disclination dipole is exact also from the energetic standpoint

3D bioprinting of multifunctional alginate dialdehyde (ADA)–gelatin (GEL) (ADA-GEL) hydrogels incorporating ferulic acid

: The present work explores the 3D extrusion printing of ferulic acid (FA)-containing alginate dialdehyde (ADA)-gelatin (GEL) scaffolds with a wide spectrum of biophysical and pharmacological properties. The tailored addition of FA (≤0.2 %) increases the crosslinking between FA and GEL in the presence of calcium chloride (CaCl2) and microbial transglutaminase, as confirmed using trinitrobenzenesulfonic acid (TNBS) assay. In agreement with an increase in crosslinking density, a higher viscosity of ADA-GEL with FA incorporation was achieved, leading to better printability. Importantly, FA release, enzymatic degradation and swelling were progressively reduced with an increase in FA loading to ADA-GEL, over 28 days. Similar positive impact on antibacterial properties with S. epidermidis strains as well as antioxidant properties were recorded. Intriguingly, FA incorporated ADA-GEL supported murine pre-osteoblast proliferation with reduced osteosarcoma cell proliferation over 7 days in culture, implicating potential anticancer property. Most importantly, FA-incorporated and cell-encapsulated ADA-GEL can be extrusion printed to shape fidelity-compliant multilayer scaffolds, which also support pre-osteoblast cells over 7 days in culture. Taken together, the present study has confirmed the significant potential of 3D bioprinting of ADA-GEL-FA ink to obtain structurally stable scaffolds with a broad spectrum of biophysical and therapeutically significant properties, for bone tissue engineering applications

Numerical investigation of a 3D hybrid high-order method for the indefinite time-harmonic Maxwell problem

Hybrid High-Order (HHO) methods are a recently developed class of methods belonging to the broader family of Discontinuous Sketetal methods. Other well known members of the same family are the well-established Hybridizable Discontinuous Galerkin (HDG) method, the nonconforming Virtual Element Method (ncVEM) and the Weak Galerkin (WG) method. HHO provides various valuable assets such as simple construction, support for fully-polyhedral meshes and arbitrary polynomial order, great computational efficiency, physical accuracy and straightforward support for hp-refinement. In this work we propose an HHO method for the indefinite time-harmonic Maxwell problem and we evaluate its numerical performance. In addition, we present the validation of the method in two different settings: a resonant cavity with Dirichlet conditions and a parallel plate waveguide problem with a total/scattered field decomposition and a plane-wave boundary condition. Finally, as a realistic application, we demonstrate HHO used on the study of the return loss in a waveguide mode converter

Numerical Simulation of Heat Pipe Thermal Performance for Aerospace Cooling System Applications

The design of integrated and highly efficient solutions for thermal management is a key capability for different aerospace products, ranging from civil aircraft using hydrogen on board to miniaturized satellites. In particular, this paper discloses a novel numerical tool for the design and thermal performance assessment of heat pipes. To achieve this goal, a numerical Ansys Parametric Design Language code is set up to verify the effective subtractive heat flux guaranteed by the selected heat pipe arrangement. The methodology and related tool show their ability to provide good thermal performance estimates for different heat pipe designs and operating conditions. Specifically, the paper reports two very different test cases: (1) solid metal heat pipes to cool down the crotch leading-edge area of the air intake of a Mach 8 civil passenger aircraft, and (2) a copper-water heat pipe to cool down a Printed Circuit Board of a generic small LEO satellite. The successful application of the methodology and numerical code confirms the achievement of the ambitious goal of developing in-house tools to support heat pipe thermal performance prediction for the entire aerospace domain

Abstractive video lecture summarization: applications and future prospects

Modern educational technology systems allow learners to access large amounts of learning materials such as educational videos, learning notes, and teaching books. Automated summarization techniques simplify the access and exploration of complex data collections by producing synthetic versions of the original content. This paper addresses the problem of video lecture summarization by means of abstractive techniques. To enhance the accessibility of the video lecture content in challenging contexts or while coping with learners with special needs it produces a synthetic textual summary condensing the key concepts mentioned in the lecture's speech. Unlike prior works based on extractive methods, the proposed method can produce more readable and actionable summaries, not necessarily composed of existing portions of speech content. To compensate the lack of annotated data, it also opportunistically reuses the pretrained models available for meeting summarization. The experimental results achieved on a benchmark dataset show that the proposed method generates more fluent and actionable summaries than prior approaches simply relying on content extraction. Finally, we also envision further applications of summarization techniques to learning content. The future prospects of use of summarization techniques in education have shown to go well beyond video summarization

Appropriate strengthening technologies for the mitigation of seismic vulnerability of Bhutanese vernacular stone masonry architecture

Bhutanese vernacular stone masonry architecture proved highly vulnerable to the recent seismic events affecting Bhutan since 2009. The isolation of rural communities, due to the site geomorphology, the precarious roads networks condition, the local labour limited skills, and the scarce resources availability, largely influence the applicability of strengthening technologies for traditional stone masonry architecture’s seismic vulnerability mitigation. Following up the collaboration with the Royal Government of Bhutan, within an international research project, the paper aims to analyse the appropriateness and suitability of strengthening intervention strategies to the local context. The identified strategies have been associated with the analysis of the stresses causing the failure mechanisms occurred during the 2009 earthquake and tailored to local construction technologies. A full-scale static test carried-out on a stone masonry-building mock-up, allowed to evaluate its behaviour under static loads. As a final result, the suitability of the interventions has been evaluated through qualitative indicators

Digital Twin, Virtual Reality and Metaverse: what technologies to support the asset management workforce?

The challenging paradigm of the Digital Twin of construction combined with the new possibilities offered by information and visualization technologies provide innovative ways to approach, study, and investigate the risk and vulnerability of an area. The Digital Twin is proposed as a digital copy of an artefact, city or territory overcoming the use of Geographic information system (GIS) and Building Information Models (BIM) as capable of establishing a bi-directional data transfer between the physical object and the model (Khallaf et al., 2022). On the other hand, three-dimensional dealing with infrastructure has opened up new horizons related to communication and the fruition of the assets, expanding the pool of users that can be reached. If the digital model is the computer representation of the work containing all the information for its life cycle, the virtual model is an interactive simulation of it. The Spoke TS2 of the RETURN project also reflects how these methodological and technological advances can be leveraged to enhance the asset management workforce and forecasting capacity. In particular, situational awareness applications are considered for the staff's re-skilling and up-skilling. In this context, WebGIS platforms, Virtual Reality experiences, and the new frontier of the Metaverse can play a role. Geospatial technologies promote spatial thinking skills and enhance content knowledge necessary to examine linear infrastructure, which requires a multi-scalar approach concerning their specific connotation. Possible integration with BIM, which examines the scale of the point artefact, enhances the system capability by allowing it to move from particular to broader context. As understanding the context is necessary for comprehending the problems, the WebGIS framework enables integration, simulation, analysis, and visualization of the GIS technology result in an online environment. The distribution of spatial geographic information is, at this point, interfaced with big data from the sensor network, empowering stakeholders’ decisions based on real-time changing situations. Through Decision Support Systems, they can have valuable information for planning and management without so much effort and time. According to the literature, incorporating traditional knowledge into modern technology is suitable for disaster risk reduction education. In recent years, web hazard maps have received attention not only from experts but also from students (Song et al., 2022), and flood resilience information systems for raising awareness among citizens (Albano et al., 2015). On the other hand, the navigability of the model achievable through Virtual Reality (Ghobadi et al., 2020) technologies overturn the condition of the observer on both an experiential and conceptual level. Starting from digital models, it is possible to promote engaging and stimulating cognitive experiences to illustrate even to a non-technical or non-expert audience how complex constructions work so that political and economic choices can be made with greater awareness. The immediacy and hypermedia nature of the graphical representation makes the virtual model a powerful tool that enables more effective dialogue in, for example, local authorities planning conferences and service meetings. At the same time, it makes it possible to create innovative training solutions for the training of actors who operate in different roles on infrastructures: improving knowledge of sites, even those that are difficult to reach; transferring skills for maintenance; simulating or reproducing critical situations (Tender et al., 2023), such as emergencies or failures, which when they occur require a rapid response. Let us imagine the potential and stakeholder interest in simulating an accident interconnected perhaps to a natural event on a railroad tunnel section. Examining the situation in a realistic and safe environment without needing to be in the field allows for the best assessment of safety procedures and operation management efficiency while also reducing costs. As the final frontier, the Metaverse (Ritterbusch et al., 2023) emerges as the further evolution of these immersive and multimedia environments by enabling their interconnection and decentralization based on open platform. Unlike the traditional virtual world, the concept of community emerges strongly, emphasizing much more realistic interaction between people and with their surroundings. As we glimpse the possibilities are remarkable. Are we ready for change

Comparison of Different Approaches to Derive Global Safety Factors for Non-linear Analyses of Slender RC Members

The present study relates to comparison between different approaches for definition of global safety factors for non-linear analysis of slender RC members with reference to new or existing structures. Firstly, a benchmark set of 40 experimental results on reinforced concrete columns is presented. After the description of the main features of the benchmark test sets the related non-linear numerical models have been realized using fiber-modelling as solution strategy. Then, appropriate assumptions concerning aleatoric and epistemic uncertainties have been performed with the aim to run probabilistic analysis of global resistance for each one of the 40 columns. The results of the probabilistic analysis are useful to define global safety factors in line to the global resistance method. Finally, the comparison between different approaches to derive global safety factors is presented and discussed