Search Results (59)

This research work focuses on the chemical recycling of a Carbon Fiber-Reinforced Composite (CFRC) manufactured through a vacuum-assisted resin infusion (VARI) process, characterized by a high Young’s modulus of approximately 7640 MPa. The recycling reaction was performed using a mixture of eco-sustainable solvents, composed of acetic acid and hydrogen peroxide, and was conducted at three different temperatures (70, 80, and 90 °C). The reaction yield values, evaluated with an innovative approach that involved the use of thermogravimetric analysis (TGA), confirmed the importance to recycle at a temperature corresponding to the glass transition temperature (Tg = 90.3 °C) of the resin. Spectroscopic investigations highlighted that the chemical bond cleavage occurred through the selective breaking of the C-N bonds of the cross-linked matrix structure, allowing the recovery of both the reinforcing phase of the epoxy matrix and the initial oligomers/monomers of the epoxy matrix. The morphological and electrical investigations carried out on the recovered fibers further confirmed the efficiency of the recycling process conducted at the highest explored temperature, allowing the recovery of cleaner fibers with an electrical conductivity value (8.04 × 10² S/m) closer to that of virgin fibers (2.20 × 10³ S/m). The proposed strategy is a true challenge in terms of saving energy, solving waste disposal problems, preserving the earth, and preventing the depletion of planet resources. Full article

Current issues in sustainable development concern research on comprehensiveness, coherence and practicality. Therefore, the objective was to develop and test a novelty approach to product sustainability assessment based on life cycle, quality, and costs. This approach extends the iterative design thinking process (DT), including overcoming the limitations of existing LCSA methods. We present a systematic process for obtaining and processing customer requirements with a survey and Pareto–Lorenz analysis. Then, using an algorithm developed in Matlab R2021a program, we generated product prototypes considering the key criteria presented in various dimensions of current and modified states. Next, we propose the modeling of prospective LCA for all prototypes in the OpenLCA program with Ecoinvent database. Finally, we aggregated the results considering the cost of prototypes in environmental–cost analysis to determine the direction of product sustainability. We tested this approach in detail with the example of vacuum cleaners for domestic and commercial use. After a literature review and survey research in customers, we developed 54 prototypes, where the modified key quality criteria were as follows: vacuum in the suction pipe, engine power, operating range, and length of the power cable. Using this approach, it was possible to select six prototypes that best meet customer requirements, are environmentally friendly, and cost-effective. Finally, we discuss contributions to DT and LCSA methodologies, and propose future directions for development within the application of artificial intelligence (AI). This approach can be a practical application in SMEs already in the early stages of product development (conceptualization), where access to detailed data is limited. Full article

Many tasks in a modern household are performed by machines, e.g., a dishwasher or a vacuum cleaner, and in the near future most household tasks will be performed by smart service robots. This will relieve the residents, who in turn can enjoy their free time. This newly gained free time will turn out to cause the so-called spare time rebound effect due to more resource consumption. We roughly quantify this rebound effect and propose a CO₂-budget model to reduce or even avoid it. In modern industry, automation and AI are taking over work from humans, leading to higher productivity of the company as a whole. This is the main reason for economic growth, which leads to environmental problems due to higher consumption of natural resources. We show that, even though the effects of automation at home and in the industry are different (free time versus higher productivity), in the end they both lead to more resource consumption and environmental pollution. We discuss possible solutions to this problem, such as carbon taxes, emissions trading systems, and a carbon budget. Full article

Small- and medium-sized enterprises (SMEs) play a vital role in the global economy, driving innovation and economic growth, despite constraints on their financial and operational resources. In the competitive landscape of modern markets, continuous product design improvement has become essential for SMEs to meet dynamic user requirements, enhance satisfaction, and maintain competitiveness. Online reviews have emerged as valuable sources of user feedback, offering real-time, large-scale insights into user preferences. However, existing methods for leveraging online reviews in product design improvement have significant limitations, including insufficient attention paid to the hierarchical structure of different attributes when extracting product improvement attributes and a lack of quantitative attribute prioritization strategies. These shortcomings often result in suboptimal improvement and inefficient resource allocation, particularly for SMEs with limited resources. To address these challenges, this study proposed a novel online review-assisted method for product design improvement tailored to the needs of SMEs. The proposed method incorporates a hierarchical latent Dirichlet allocation model to extract and organize product attributes hierarchically, thereby enabling a comprehensive understanding of user requirements. Furthermore, a marginal utility-based approach is employed to prioritize product improvement attributes quantitatively, ensuring that the most impactful attributes are addressed efficiently. The effectiveness of the proposed method was demonstrated through a case study on the design improvement of a robotic vacuum cleaner developed using a typical SME in robotic cleaning solutions. Full article

Among nanomaterials, silver nanoparticles (AgNPs) are cost-effective and exhibit unique physicochemical properties that enable them to become the most used agents for the manufacture of various products known as nano-enabled, including those for personal care, drugs, fabrics, sprays, disinfectants, vacuum cleaners, and air conditioners, with a continuous expansion to different sectors. Industrial discharges, the disposal of wastewater treatment effluents, and indirect runoff from the soil are some factors that are increasing the accumulation of AgNPs in aquatic and wetland ecosystems. Herewith, we critically analyze the progress in the research of the uptake and translocation of AgNPs in aquatic and wetland plants and their phytotoxic effect that depends on the concentration, size, distribution, morphological shape, surface characteristics and chemical composition of the nanoparticles, as well as the plant genotypes, among other factors. Due to biological plasticity, the toxicity level of AgNPs may vary among plant species, which may be further affected by the mode of application, time of exposure, and plant conditions (e.g., agronomic management, growth rate, phenological stage, etc.). Therefore, it is possible to identify and select competent plants for phytoremediation purposes, including superior capabilities for phytoextraction, phytofiltration, and phytostabilization. The review also identifies the main gaps that require attention in future research in order to elucidate a more integrative map aimed to reduce the potential threats to the environment and living organisms including humans. Full article

Material recycling is vital for achieving carbon neutrality because using recycled materials helps avoid greenhouse gas (GHG) emissions that result from using virgin material. Carbon tax has been introduced in many countries to reduce GHG emissions. As recycling can prevent additional GHG emissions, the carbon tax should be refunded based on the GHG volume saved by recycling. The incentive of carbon tax refund can help promote recycling as an environment-friendly and economical activity. To retrieve material values from end-of-life (EOL) products, a reverse supply chain network should be designed based on the status and value of EOL products. This study introduces carbon tax refund into the reverse supply chain network for maximizing saved GHG emissions and minimizing cost. The bi-objective model is formulated using $\mathsf{ϵ}$ constraint method and integer programming. Numerical experiments were conducted based on the recycling of a vacuum cleaner and a laptop. The monetary rate at which the carbon tax refund became economically attractive differed according to product type. Thus, variable carbon tax refund rates would be needed, based on product type, to incentivize recycling. Full article

Heel marks (HMs) are a type of dirt stain consisting of polyester-based urethane rubber on polyvinyl chloride (PVC) floor surfaces. The rapid removal of HMs was achieved by using non-thermal atmospheric-pressure plasma technology. Mimetic HMs were prepared by coating PVC floor samples with HMs to a thickness of 13.9 μm. The removal area, thickness, and volume were measured after applying spark discharges at high voltage and a repetition rate of 50 kHz. The treated surfaces were analyzed by using X-ray photoelectron spectroscopy (XPS) and pyrolysis–gas chromatography with time-of-flight mass spectrometry (Py-GC/TOFMS). Removal rates of 20 mm²/min in area, 52 mm³/min in volume, and 7 μm/min in depth were achieved with an inter-electrode distance of 10.0 mm and an air flow rate of 20 standard liters per minute. A removal depth of 10 μm/min was achieved without air supply. The mechanism of stain removal by spark discharge was modeled by decomposing the original high-molecular-weight molecules in polyester-based urethane rubber into low-molecular-weight molecules, such as methylene diisocyanate (MDI) components. The results of this study may facilitate the development of a novel electric vacuum cleaner capable of removing floor stains. Full article

Electrical arc fault detector development requires many tests to develop and validate detection algorithms. The use of artificial intelligence or mathematical transformation requires the use of consequential datasets of current signatures corresponding to as many different situations as possible. In addition, one of the main drawbacks is that these experiments take a great deal of time and are often laborious in the laboratory. To overcome these limitations, a virtual test bench based on the modeling of a modular 230 VAC electrical circuit has been developed. The simulated network is composed of different home appliances (resistor, vacuum cleaner, dimmer, etc.) and its configurations are those of single and combined loads. The fault modeled is an electric arc, modeled by active diode switching, which can be inserted at any point of the circuit. This arc model takes into account the random variations in the restrike and arc voltage. All the appliance models are validated by comparing the frequential (harmonic distortion) and temporal (agreement index) signatures of the measured currents in real situations to those obtained by modeling. The results obtained using the model and experiment network show that the current signatures are comparable in both cases. Further, two detection algorithms are tested on those current signatures obtained by the modeling and experimentation. The results are comparable and provide identical detection thresholds. Full article

This paper introduces a new method for identifying museum pests through the analysis of DNA present in settled dust. Traditionally, the identification of pests in cultural institutions such as museums and depositories has relied on insect trapping (monitoring). They give good results but need time (minimum spring until summer of one year for a complete survey) and face challenges related to the identification of small, rare, or damaged species. Our study presents a non-invasive approach that utilizes metabarcoding analysis of dust samples to identify pests and other arthropods at the species level. We collected dust samples with a handheld vacuum cleaner in summer 2023 from the six different floors of the Natural History Museum in Vienna and compared the results with the insect monitoring. We found over 359 different species of arthropods in the museum and could show how the diversity increases with the elevation of the building floor. This method could be used for rapid and cost-effective screening of pests before monitoring. But the interpretation of results is sometimes difficult (for Lepismatidae, for example), and it cannot replace a continuous monitoring of pests with traps. This investigation might present the highest indoor animal biodiversity ever found in a single building. Full article

Robots and smart technologies are becoming part of everyday life and private households. While this automation of mundane tasks typically creates pragmatic benefits (e.g., efficiency, accuracy, time savings), it may also come with psychological losses, such as in meaning, competence, or responsibility. Depending on the domain (e.g., AI-assisted surgery, automated decision making), especially the user’s felt responsibility could have far-reaching consequences. The present research systematically explores such effects, building a more structured base for responsible automation in human–computer interaction (HCI). Based on a framework of seven dimensions, study 1 (N = 122) evaluates users’ reflections on automating five mundane tasks (e.g., gardening, paperwork) and identifies reasons for or against automation in different domains (e.g., creativity, care work, decision making). Study 2 (N = 57) provides deeper insights into effects of automation on responsibility perceptions. Based on the example of a vacuum cleaner robot, an experimental laboratory study contrasted a non-robotic manual vacuum cleaner to a robot, whereby the user’s perceptions of device agency (higher for the robot) and own competence (higher for the manual device) were central mediators for the perceived responsibility for the result. We position our findings as part of a broader idea of responsible design and automation from a user-centered design perspective. Full article

Huge amounts of Au and Ag are recovered from the hazardous waste lead anode slime. The conventional extraction of precious metals from lead anode slime is based on pyrometallurgical and electrolytic processes, which are seriously conditioned by the separation of harmful elements As and Sb. In this paper, an innovative and efficient oxidation–vacuum volatilization–carbon reduction process was proposed to separate and enrich Ag and Au from lead anode slime. Before vacuum volatilization, selective oxidation of the lead anode slime was performed. Then, vacuum volatilization and vacuum carbon reduction were used to obtain a gold- and silver-rich alloy. The feasibility of the process was verified experimentally and theoretically. The effects of temperature and time on vacuum volatilization separation and reduction enrichment were investigated. The experimental results showed that the Ag content in the resulting gold- and silver-rich alloy was as high as 67.58%, Au was as high as 4287 g/t, and the efficiencies for the recovery of Ag and Au from the lead anode slime were 99.25% and 99.91%, respectively. The gold- and silver-rich alloy can be directly used to produce Ag ingots. Moreover, no gas or wastewater was discharged in this process, so Ag and Au were recovered in a sustainable and cleaner manner. Full article

The ureteral access sheath (UAS) has been a boon and a bane in flexible ureteroscopy (FURS), with its merits and demerits well established. Its design and dimensions were instrumental in reshaping the way flexible scopes were used and were key adjuncts to establishing retrograde intrarenal surgery (RIRS) as a standard of care in the endourological management of renal stones. With the ever-changing landscape of RIRS over the decades shaped by technological advancements in lasers and flexible scopes, the UAS has also continuously evolved. The utility of suction in endourology has recently changed the way RIRS is performed and is a game changer for FURS outcomes. With strong clinical and experimental evidence to support its use, the UAS has undergone a transformative change in the recent past, with its ability to monitor intrarenal pressure and provide a superior vacuum-cleaner effect that improves the trifecta of RIRS, namely an improved single-stage stone-free rate (SFR), minimise complications, and reduce reinterventions. Our comprehensive review outlines the key clinical and experimental evidence and traces the developments that were key to modifying the traditional UAS into a flexible and navigable suction ureteric access sheath (FANS) and highlights how the design and modifications, in turn, influence the ability to push the boundaries of RIRS. Full article

In the era of the competitive environment, the improvement in current products is ensured through activities aimed at increasing a product’s quality level and, consequently, reducing the amount of waste. The dynamically changing production environment and sudden changes in customer expectations force us to take precise and well-thought-out development steps. Furthermore, it is important to anticipate favourable product changes to prepare for market changes over time. This is still an open problem. The aim of this study was to develop a method to predict the quality of potential product prototypes resulting from the proposed modifications of the product features. This methodology takes into account current customer expectations. The method was created based on the principles of creating Quality Function Deployment (QFD) in the context of taking into account current and future customer expectations regarding product features. This is a new approach to analysing product quality within the principles of the traditional QFD method. The originality of the study is the technique used in the method to estimate the expected values of product features and their importance (weights), taking into account current customer expectations. Its originality is also manifested in drawing conclusions supporting the decision-making process of product improvement, because it involves ensuring the pro-quality modification of selected features of current products in the order that is most advantageous from the customer’s point of view. The use of the proposed method allows for the analysis of the impact of modifying the current value of a product feature. The method is illustrated with an example of a vacuum cleaner for home use. However, the proposed method can be applied to the design of any product to predict products that will meet customer expectations. Full article

The global and Australian trends indicate a steady increase in the generation of small waste electrical and electronic equipment (WEEE), constituting 30% of global WEEE in 2019 with an expected 90% increase in Australia over the next 25 years. Given this fact, identifying the most suitable circular economy strategy is vital in managing this waste stream. Hence, followed by a review of the literature, a model was developed to assess the suitability of repair, reuse, and recycling of small electrical and electronic equipment (EEE) by considering the lifespan and products put on the market (PoM) as critical variables. Findings indicate that solely repairing and reusing products, without reducing PoM small EEE, minimally affects short-term waste reduction. A synergistic approach, combining high product reuse with reduced PoM small EEE, is essential to decrease small WEEE generation significantly. Regardless of lifespan changes, the study indicates a proportional relationship between small WEEE generation rates and PoM small EEE changes, emphasising the need for a holistic strategy. Considering this, within stewardship schemes, the primary focus should initially lie on repairing and repurposing small EEE, with the potential for expansion into recycling once sufficient infrastructure and achievable recovery goals are established. Original equipment manufacturers (OEMs) must shoulder substantial accountability, with a firm commitment to extended producer responsibility (EPR) even for historical products. The initial rollout could target four specific categories: toys, food preparation equipment, vacuum cleaners, and household tools, with the scope widening to encompass all categories following successful implementation. Full article

Improving product sustainability is becoming an increasingly significant challenge for modern enterprises. A growing number of manufacturers are interested in enhancing product sustainability throughout the product life cycle. This study is concerned with using case-based reasoning to identify ways of improving product sustainability and select variables for model specification. Parametric models are applied to search for opportunities to improve product sustainability. This can be achieved through changes introduced at the product design stage. Simulations are performed using constraint-satisfaction modeling to identify conditions for achieving the sustainability targets of new products. Constraint-satisfaction modeling provides a suitable framework for finding all possible sustainability-enhancing changes (if any) during the new product development process. These changes may support R&D specialists in identifying opportunities to improve the sustainability of new products. We demonstrate the usefulness of the proposed approach with an example in which our method enabled a reduction in the product failure rate and an increase of battery lifespan for a robot vacuum cleaner line. We analyzed several factors affecting two targets of product sustainability: minimizing the product failure rate and maximizing battery lifespan. Our findings indicate that R&D staff size is the biggest factor in reducing the product failure rate, and that battery capacity is the most significant factor in battery lifespan. Full article