1,720,959 research outputs found
De-manufacturing Analysis for Product Repairability and Serviceability in Cooking Systems
No full textNew standards (e.g., the EN4555X series) and indices have been issued to include repairability aspects in product design. These indices are very useful in the design phase to characterize the product and to understand the ability of products to be disassembled. The goal of this paper is to address product repairability and ease of disassembly for cooking systems, with a specific focus on induction hobs. A four steps approach was followed encompassing project definition, laboratory tests, disassemblability index calculation, and eco-design actions definition for product improvement. Project definition includes the identification of target components for service/repair purposes, while laboratory test allows retrieval of disassembly data in accordance with EN 45554 standard. The disassemblability index calculation brings to the identification of design criticalities that affect the repairability score providing important insight into the identification of eco-design actions. The implementation of the eco-design actions, when applied in the product development process, will lead to an increment in repairability and serviceability performance for the identified target components
Design for manufacturing and assembly methods in the product development process of mechanical products: a systematic literature review
Full text linkThe design for manufacturing and assembly (DFMA) is a family of methods belonging to the design for X (DfX) category which goal is to optimize the manufacturing and assembly phase of products. DFMA methods have been developed at the beginning of the 1980s and widely used in both academia and industries since then. However, to the best of the authors’ knowledge, no systematic literature reviews or mapping has been proposed yet in the field of mechanical design. The goal of this paper is to provide a systematic review of DFMA methods applied to mechanical and electro-mechanical products with the aim to collect, analyse, and summarize the knowledge acquired until today and identify future research areas. The paper provides an overview of the DFMA topic in the last four decades (i.e., from 1980 to 2021) emphasizing operational perspectives such as the design phase in which methods are used, the type of products analysed, the adoption of quantitative or qualitative metrics, the tool adopted for the assessment, and the technologies involved. As a result, the paper addresses several aspects associated with the DFMA and different outcomes retrieved by the literature review have been highlighted. The first one concerns the fact that most of the DFMA methods have been used to analyse simple products made of few components (i.e., easy to manage with a short lead-time). Another important result is the lack of valuable DFMA methods applicable at early design phases (i.e., conceptual design) when information is not detailed and presents more qualitative than quantitative data. Both results lead to the evidence that the definition of a general DFMA method and metric adaptable for every type of product and/or design phase is a challenging goal that presents several issues. Finally, a bibliographic map was developed as a suitable tool to visualize results and identify future research trends on this topic. From the bibliometric analysis, it has been shown that the overall interest in DFMA methodologies decreased in the last decade
Implementation of Eco-Design Actions in the Development of a Sustainable Heat Exchanger in a Life Cycle Perspective
No full textAccording to the European energy consumption reports, the highest energy consumption in residential sector is due to space heating, followed by water heating. Generally, the product used to warm water in residential building is the boiler where heat exchanger is the core of the system. The paper aims to develop a novel concept of heat exchanger by following eco-design actions retrieved by the analysis of life cycle performance. Several eco-design actions were put into practice to reduce the environmental issues in each phase of the life cycle. Concerning the materials and manufacturing phase, a novel design based on different material (i.e., stainless steel) was developed to replace a mix of materials (i.e., copper and aluminum alloy). Concerning the use phase, the overall product efficiency was increased allowing important savings in terms of gas/energy consumptions. Finally, concerning the end-of-life phase, brazing processes was replaced by other joining processes to increase component’s disassembly and varnishing process was avoided due to the better corrosion resistance performance of the stainless steel. The new heat exchanger shows better environmental performance in each Life Cycle Assessment indicator, saving more than 40% in CO2 emissions (GWP) in the whole product life cycle
Eco-design actions to improve life cycle environmental performance of face masks in the pandemic era
Full text linkFace 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
Engineering eco-design of heat exchangers in domestic heating systems using life cycle assessment methodology
No full textAccording to the European energy consumption reports, the highest energy/fuel consumption in the residential sector is due to space heating, followed by water heating. Generally, the product used to warm water in residential buildings is a boiler system where a heat exchanger is the core of the system. The paper provides a Life Cycle Assessment analysis of a traditional heat exchanger used in domestic boilers with the aim to identify critical aspects and environmental hotspots for the development of a novel concept of the heat exchanger. The methodology used to collect eco-design guidelines from the Life Cycle Assessment analysis is proposed within the paper. Several eco-design actions were put into practice to reduce the environmental issues in each phase of the life cycle from the materials used, the manufacturing processes as well as the product geometry to increase energy efficiency during the use. Concerning the materials and manufacturing phase, a novel design based on a different material (e.g., stainless steel) was developed to replace a mix of materials (i.e., copper and aluminum alloy). Concerning the use phase, the overall product efficiency was increased allowing important savings in terms of gas/energy consumption, by the adoption of a novel design (e.g., spiral pipe). The new heat exchanger design shows better environmental performance in each Life Cycle Assessment indicator, saving more than 40% in CO2 emissions (Global Warming Potential) in the whole product life cycle
Static and fatigue strength of laser-textured adhesive-bonded polyamide 66 (PA 66) joints
Full text linkNanosecond pulsed laser texturing has been performed as surface preparation for adhesive-bonded polyamide 66 (PA 66) joints. A Design-of-Experiments approach was firstly applied for optimization of laser parameters in terms of static joint strength, after which the fatigue strength of the best performing joints was determined. Quasi static and fatigue lap shear tests were performed on joints bonded with Teroson PU 9225. Laser texturing of PA 66 was found to be far less sensitive to heat accumulation in the hatch direction than in the laser scanning direction. Static average shear strength was generally found to increase with laser energy dose up to approximately 8–20 J/cm2, while no correlation was observed between the microscale surface roughness and static strength for low values of the former (Sa < 2 μm). A shear strength of 11.60 MPa was achieved with a parallel-line scanning strategy and an average laser power of 3 W, hatch spacing of 50 μm and scanning velocity of 700 mm/s, representing a three-fold increase over standard primed joints. Laser-textured joints prepared with the same parameters exceeded the fatigue performance of atmospheric pressure plasma, mechanical abrasion and primer pre-treatments at both high and low maximum average cyclic shear stress, implying that laser texturing is an appropriate solution for improving bonding at high cyclic shear stress and prolonging the crack propagation phase at low cyclic shear stress
Sustainable design and life cycle engineering of adhesive joints for polymeric products: assessment of surface activation technologies
No full textThe adoption of lightweight materials in engineering applications has become more popular over recent years, with adhesives replacing traditional joining methods such as bolts and rivets. Adhesion science and related technologies are arising as cleaner options for sustainable production in modern industry, with adhesive-bonded joints increasingly being used as design solutions in complex products and assemblies. However, the use of structural adhesives has several significant drawbacks, most of which are related to environmental impact, linked to the nature of the adhesive substance, as well as product disassembly/disposal deriving from the fact that adhesive joints are usually irreversible. Within this context, the goal of this paper is to study adhesive joints in mechanical assemblies from a life cycle perspective, offering more comprehensive analysis tools and assembly solutions suitable for industries such as automotive, aerospace, and assembly/packaging machinery. A methodological framework for the comprehensive characterization of bonded joints using effective surface activation techniques has been created and tested. The first phase encompasses the production of samples for mechanical testing under static and fatigue loading conditions. The second includes the characterization of inputs/outputs (life cycle inventory—LCI) for life cycle assessment (LCA) of mechanical assemblies employing adhesive joints and innovative surface activation techniques. The final phase provides a set of eco-design actions based on a critical analysis of the obtained results. The outcomes demonstrate how it is possible to achieve optimal adhesive-bonded joint properties under specific working conditions (e.g., static or fatigue loading) while maintaining a low environmental load using novel surface pre-treatments such as laser and plasma technologies. These outcomes are supported by a case-study in which adhesive joints are applied to the mechanical assembly of a bottle gripper for a food packaging machine. The adoption of eco-design rules in adhesive joint applications will help designers in the development of suitable solutions for lightweight applications from a complete life cycle perspective
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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