A Framework to Collect and Reuse Engineering Knowledge in the Context of Design for Additive Manufacturing

Design for AM (DfAM) requires the definition of Design Actions (DAs) to optimize AM manufacturing processes. However, AM understanding is still very blurred. Often designers are challenged by selecting the right design parameters. A method to list and collect DfAM DAs is currently missing. The paper aims at providing a framework to collect DfAM DAs according to a developed ontology to create databases (DBs). DBs were tested with two real case studies and geometric features to improve identified. Future developments aim at widening the database to provide all-around support for AM processes

Engineering design in food-packaging industry: The case study of a tuna canning machine

Food packaging industry requires machines able to perform different tasks and carry out several functions. Machine modularization allows to feed customer's needs creating a set of equipment with different features and technology. Module derivation is particularly important at the conceptual phase where main decisions are taken and where the degree of freedom are higher, avoiding subsequent costly modification. This study aims at investigating the adoption of engineering design process for the development of a tuna canning machine, deriving main modules for a definition of a product platform. The possibility to have a modular framework in this type of products allows to satisfy constraints coming from different markets and applications (i.e., product quality, adaptability, upgradability, assemblability, compliance with standards where the machine is installed, etc.). Modules were derived based on state-of-art approaches used for product development (i.e., functional analysis, module derivation and morphological matrix) and two examples (i.e., Cutter and Compactor & Shaper modules) were detailed to explain the developed design solutions. Results highlight how different design options can be adopted to overcome several issues (i.e., assemblability, upgradability) and fulfill requirements of different markets (i.e., product quality and aesthetic)

Environmental implication of personal protection equipment in the pandemic era: LCA comparison of face masks typologies

In the present global health emergency, face masks play a key role in limiting the diffusion of the COVID-19 pandemic, by acting as physical barriers to avoid droplets and filtrate exhalations coming from infected subjects. Since the most widespread devices are disposable products made of plastic materials, this means that relevant quantities of fossil resources will be consumed, and huge amounts of wastes will be generated. The present paper aims to compare the environmental performances of five different typologies of face masks (i.e. 3D printed reusable mask with filter, surgical mask, filtering face-piece masks-FFPs with and without valve, washable masks), considering an average Italian use scenario and the whole mask lifecycle: materials, manufacturing processes, use, sanitization, and disposal. The Life Cycle Assessment methodology has been used to assess the environmental impacts in terms of both ReCiPe midpoints and endpoints. Reusable masks and masks with interchangeable filters could potentially contribute to improve the environmental performances in all the considered impact and damage categories. Eco-design actions can be developed starting from the study results

Challenging the engineering design process for the development of facial masks in the constraint of the COVID-19 pandemic

The most effective ways to mitigate the diffusion of the COVID-19 pandemic are social distancing and the use of face masks as barrier to avoid droplets and to filtrate exhalations coming from infected subjects. Currently used face masks are products developed to be used by workers, both in health care and other contexts, where their use is limited in time and the disposal scenario is properly managed. Their use in a pandemic situation can be thus considered a remedial action due to the emergency. New masks or mask families are needed based on the desirable requirements retrieved by the analysis of the current worldwide situation and covering the gap observed in the market. The present paper aims to describe the complete product development process of a new facial mask (or mask family) for a daily use on a pandemic situation. It challenges the time constraint of the COVID-19 pandemic by adopting a four-step approach and concurrent development of the first phases (definition of requirements and functional derivation). The engineering design process allows to derive two different solutions able to fulfil all the requirements (demands and wishes) of final users, by assuring high ergonomic performance, as well as environmental, economic, and social sustainability

Eco-design actions to improve life cycle environmental performance of face masks in the pandemic era

Face masks are currently considered essential devices that people must wear today and in the near future, until the COVID-19 pandemic will be completely defeated through specific medicines and vaccines. Such devices are generally made of thermoplastic polymers, as polypropylene and polyethylene and are single use products. Even if in this period the sanitary emergency must have the maximum priority, the world society should not completely forget the environmental problem that are causing more and more obvious climate changes with correlated damages to ecosystems and human health. Despite the well-known correlation among anti-COVID protective equipment (or more generally medical devices) and environmental issues, the Life Cycle Assessment (LCA) and eco-design-based studies in this field is very scarce. The present study aims to derive the most important environmental criticalities of such products, by using LCA and product circularity indicators of five different common masks. The final aim is to provide eco-design guidelines, useful to design new face masks by preventing negative impact on the environment

Impact assessment of design guidelines in the conceptual development of aircraft product architectures

The optimization of the assembly phase, in complex products, is a challenging phase and it need to be handled in the early phase of product development (i.e., conceptual design). Several methods have been developed to assess the assemblability of product at the conceptual design phase, however, the most critical aspect concerns the possibility to derive design guidelines starting from the results of assemblability analysis. In this context, the present work aims at defining a methodology able to retrieve design for assembly and installation guidelines starting from the analysis of a given product architecture at the conceptual design phase (loop-back of the design for assembly method). The developed method makes use of matrices and vectors to provide a list of design actions that affect the product assemblability including a ranking of their impacts on the final design. The methodology was used to retrieve and select design guidelines in the context of aircraft manufacturing. The case study (cabin equipping of commercial aircraft) provides interesting results in the identification and implementation of design guidelines to improve the aircraft architecture at the conceptual level

Adipose-derived stem/stromal cells in kidney transplantation: Status quo and future perspectives

Kidney transplantation (KT) is the gold standard treatment of end-stage renal disease. Despite progressive advances in organ preservation, surgical technique, intensive care, and immunosuppression, long-term allograft survival has not significantly improved. Among the many peri-operative complications that can jeopardize transplant outcomes, ischemia-reperfusion injury (IRI) deserves special consideration as it is associated with delayed graft function, acute rejection, and premature transplant loss. Over the years, several strategies have been proposed to mitigate the impact of IRI and favor tolerance, with rather disappointing results. There is mounting evidence that adipose stem/stromal cells (ASCs) possess specific characteristics that could help prevent, reduce, or reverse IRI. Immunomodulating and tolerogenic properties have also been suggested, thus leading to the development of ASC-based prophylactic and therapeutic strategies in pre-clinical and clinical models of renal IRI and allograft rejection. ASCs are copious, easy to harvest, and readily expandable in culture. Furthermore, ASCs can secrete extracellular vesicles (EV) which may act as powerful mediators of tissue repair and tolerance. In the present review, we discuss the current knowledge on the mechanisms of action and therapeutic opportunities offered by ASCs and ASC-derived EVs in the KT setting. Most relevant pre-clinical and clinical studies as well as actual limitations and future perspective are highlighted

A stochastic approach to LCA of internal insulation solutions for historic buildings

Internal insulation is a typical renovation solution in historic buildings with valuable facades. However, it entails moisture-related risks, which affect the durability and life-cycle environmental performance. In this context, the EU project RIBuild developed a risk assessment method for both hygrothermal and life-cycle performance of internal insulation, to support decision-making. This paper presents the stochastic Life Cycle Assessment method developed, which couples the LCA model to a Monte-Carlo simulation, providing results expressed by probability distributions. It is applied to five insulation solutions, considering different uncertain input parameters and building heating scenarios. In addition, the influence of data variability and quality on the result is analyzed, by using input data from two sources: distributions derived from a generic Life Cycle Inventory database and "deterministic" data from Environmental Product Declarations. The outcomes highlight remarkable differences between the two datasets that lead to substantial variations on the systems performance ranking at the production stage. Looking at the life-cycle impact, the general trend of the output distributions is quite similar among simulation groups and insulation systems. Hence, while a ranking of the solutions based on a "deterministic" approach provides misleading information, the stochastic approach provides more realistic results in the context of decision-making

Conceptual design for assembly in aerospace industry: Sensitivity analysis of mathematical framework and design parameters

One of the most challenging activity in the engineering design process is the definition of a framework (model and parameters) for the characterization of specific processes such as installation and assembly. Aircraft system architectures are complex structures used to understand relation among elements (modules) inside an aircraft and its evaluation is one of the first activity since the conceptual design. The assessment of aircraft architectures, from the assembly perspective, requires parameter identification as well as the definition of the overall analysis framework (i.e., mathematical models, equations). The paper aims at the analysis of a mathematical framework (structure, equations and parameters) developed to assess the fit for assembly performances of aircraft system architectures by the mean of sensitivity analysis (One-Factor-At-Time method). The sensitivity analysis was performed on a complex engineering framework, i.e. the Conceptual Design for Assembly (CDfA) methodology, which is characterized by level, domains and attributes (parameters). A commercial aircraft cabin system was used as a case study to understand the use of different mathematical operators as well as the way to cluster attributes

Amide Synthesis by Nickel/Photoredox-Catalyzed Direct Carbamoylation of (Hetero)Aryl Bromides

Herein, we report a one-electron strategy for catalytic amide synthesis that enables the direct carbamoylation of (hetero)aryl bromides. This radical cross-coupling approach, which is based on the combination of nickel and photoredox catalysis, proceeds at ambient temperature and uses readily available dihydropyridines as precursors of carbamoyl radicals. The method's mild reaction conditions make it tolerant of sensitive-functional-group-containing substrates and allow the installation of an amide scaffold within biologically relevant heterocycles. In addition, we installed amide functionalities bearing electron-poor and sterically hindered amine moieties, which would be difficult to prepare with classical dehydrative condensation methods