Found 197 results
Article
17 February 2025Comparative Study of Elastomer Nanocomposites Respectively Containing SWCNTs and MWCNTs
Carbon nanotubes (CNTs) are essential for providing polymers with mechanical reinforcement and multifunctional properties. This study investigated two groups of nitrile butadiene rubber (NBR) nanocomposites containing single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), respectively. SWCNTs were purified to remove appro-ximately 20 wt.% of impurities, and both CNTs were modified with polyethylene glycol tert-octylphenyl ether (Triton X-100) before emulsion compounding and 2-roll milling with NBR. MWCNTs were found to disperse in the elastomer matrix relatively uniformly, while SWCNTs formed aggregates. Consequently, NBR/MWCNT nanocomposites exhibited superior mechanical properties, e.g. a tensile strength of 10.8 MPa at 4.02 vol.% MWCNTs, compared to 5.6 MPa for NBR/SWCNT nanocomposites. Additionally, NBR/MWCNT nanocomposites exhibited more remarkable electrical conductivity and swelling resistance to toluene. The diameter of elastomer macromolecules (0.2–0.5 nm) is close to that of SWCNTs (1–2 nm), and their single graphene wall with a hollow structure makes SWCNTs almost as flexible as elastomer macromolecules. This similarity suggests that SWCNTs should be treated as a special type of polymer. SWCNTs cannot disperse as uniformly as MWCNTs in the elastomer matrix, likely due to their smaller size and lower sensitivity to mechanical shearing during the emulsion compounding and 2-roll milling process.
Article
11 February 2025Functionalization of 3D-Printed Plastics for the Photocatalytic Removal of Organic Pollutants in Air
The study explored the use of 3D-printed plastics as catalyst supports for gas-phase photocatalytic applications. Specifically, it compared three commonly used plastic materials: PLA, ABS, and PETG. The process involved 3D modeling, additive manufacturing through 3D printing, and functionalization via dip-coating with titanium dioxide (TiO2). The study evaluated the loading capacity of the materials, the adhesion of the films, and the optical properties of the photocatalytic plates. Finally, the three plastic samples were tested as support materials in a laboratory-scale flat-plate reactor for the photocatalytic oxidation of dichloromethane in air. Loading capacities of around 3 mg/cm2 for TiO2 were achieved, along with radiation absorption capacities close to 65%. A correlation between loading and absorption fraction was identified, leading to the proposal of a simple saturation model; in turn, it allowed the predictive model of pollutant conversion as a function of the absorbed fraction of radiation. By analyzing both qualitative and quantitative properties and results, in order to determine the most suitable plastic material to be used in a photocatalytic wall reactor, PLA emerged as the best choice among the materials tested. These results show promise for the effective utilization of these plastics in the design of air decontamination devices.
Article
06 February 2025Performance Impacts of Rainwater Tanks on Stormwater Drainage Systems
This article explores the impact of using rainwater tanks on the performance of a stormwater drainage system and the possible challenges posed by climate change and future rainfall projections. This project examines a residential development in Aldinga, South Australia. The study sets clear research objectives that include the creation and simulation of drainage systems with different conditions (e.g., with and without rainwater tanks, historical data, and projected data). The aim is to analyze performance changes in the drainage network after the inclusion of rainwater tanks. Furthermore, the incorporation of projected rainfall data is considered to study possible implications of climate change on the system performance. The methodology follows a quantitative approach, with data collection, creating different models with the use of software, and simulating various conditions such as storms with different annual exceedance probabilities and varying proportions of roof area connected to rainwater tanks. Several findings are identified in this project. When roof areas of all residential allotments are connected to rainwater tanks, substantial benefits are observed in reducing peak flows within the network and runoff volumes. This proportion of connected roof area is directly correlated with reductions in peak flow. Also, while the use of projected rainfall data slightly affects benefits in peak flow and volume reduction, they will remain relatively high at least until 2050. Other performance features, such as hydraulic gradient line, long sections, and time to peak, are also explored. Study validates the hypothesis that rainwater tanks have a significant impact on runoff reductions and flood management, particularly when 100% of roof area is connected with rainwater tanks. Also, there is an impact when projected data is used, but it remains manageable and should be considered under specific contexts to decide whether these impacts are significant. Several opportunities for future research are suggested. These include the examination of larger areas, projections to a more distant future, the use of different rainfall patterns, and the consideration of extreme rainfall events.
Review
20 January 2025Adsorption and High-Value Transformation of Volatile Fatty Acids from Microbial Fermentation Products: A Review
To mitigate the aforementioned global environmental issues, the concept of carbon capture and storage is crucial in addressing the necessity for carbon peaking and carbon neutrality. The buildup of volatile fatty acids during anaerobic fermentation is a primary factor contributing to the suboptimal performance or outright failure of anaerobic digestion systems. In response to the pressing demand for volatile organic acid recovery and high-value conversion, we primarily outlined the sources, recovery techniques, adsorption materials, and methods for high-value conversion of volatile fatty acids. The methods of adsorbing volatile acetic acid were presented, encompassing adsorption materials, mechanisms, and interfacial modifications of the adsorbent. Furthermore, drawing from recent research advancements, we have synthesized the high-value conversion techniques for volatile fatty acids and evaluated the research challenges and future prospects in this domain.
Article
20 January 2025Visible Monuments above and below Ground Level, a Time-Honored Site from the Late Bronze Age to Modern Times
Due to the complex geometry of the monuments, it is often necessary to adapt the image collection process for their mapping. For the optimal mapping of the stronghold of Lazaritsa Chorygi (Greece) and its slopes, vertical, inclined, and horizontal images from different heights were collected using an Unmanned Aircraft System. Thus, for a monument of special archaeological/historical interest and natural beauty, a large set of high-spatial resolution data and final products (digital surface model and orthophotomosaic with spatial resolution 5.6 cm and 2.8 cm, respectively) is available. In addition, in the wider area of the fortified site, military structures (fire trenches, communication trenches, shelters, front and support trenches, and strong points) of the Great War length of 9 km were identified and mapped, which were identified in the 2003 or 2004 Google Earth Pro images, but worryingly are almost absent from the contemporary Google Earth Pro images.
Review
16 January 2025Biological Bone and Replacement Materials in Grinding: Force Model and Processing Capability
Grinding is widely used in orthopedic surgery to remove bone tissue material, but due to the complex and brittle structure of bone, it is prone to mechanical stresses that cause cracks and damage to the bone tissue. Furthermore, bone replacement materials typically have high hardness, strength, and brittleness, which lead to increased tool wear and damage, such as cracks and deformation during grinding. Therefore, ensuring the surface quality of bone and replacement materials during the grinding process has become a critical issue. This necessitates the development of grinding force models that consider various processing parameters, such as feed rate and cutting depth, to guide industrial production. However, currently, research on the grinding force prediction models for bone tissue and its replacement materials is relatively scarce, and there is a lack of corresponding grinding force model reviews for unified guidance. Based on this, this article focuses on bone grinding technology and, conducts a critical comparative analysis of the grinding force models for bone tissue and its replacement materials, and then summarizes the grinding force prediction models in the grinding process of bone tissue and bone replacement materials. First, according to the material types and material removal mechanisms, the materials are categorized into bone tissue, bio-inert ceramics, and bio-alloys, and the material removal process during grinding is analyzed. Subsequently, the grinding force prediction models for each material and the accuracy errors of each model are summarized. The paper also reviews the application of these grinding force prediction models, explaining how processing parameters such as feed rate and cutting depth influence grinding forces and their interrelationship. Finally, in light of the current issues in the grinding of bone tissue and replacement materials, potential future research directions are proposed, aiming to provide theoretical guidance and technical support for improving the grinding quality of bone tissue and its replacement materials.
Review
14 January 2025Artificial Intelligence and Machine Learning for Sustainable Manufacturing: Current Trends and Future Prospects
Artificial Intelligence (AI) and Machine Learning (ML) are transforming manufacturing processes, offering unprecedented opportunities to enhance sustainability and environmental stewardship. This comprehensive review analyzes the transformative impact of AI technologies on sustainable manufacturing, focusing on critical applications, including energy optimization, predictive maintenance, waste reduction, and circular economy implementation. Through systematic analysis of current research and industry practices, the study examines both the opportunities and challenges in deploying AI-driven solutions for sustainable manufacturing. The findings provide strategic insights for researchers, industry practitioners, and policymakers working towards intelligent and sustainable manufacturing systems while elucidating emerging trends and future directions in this rapidly evolving field.
Review
14 January 2025A Review of Phosphorous in Fluvial Floodplains: Source or Sink?
Fluvial floodplains are water-land transitional zones, playing an important role in hydrological and ecological systems. To date, the phosphorus migration and transformation in floodplain sediments remain elusive, which poses a large effect on river nutrient levels and primary productivity. This review summarized the sedimentary characteristics of floodplains and analyzed the spatial differences and temporal variations in phosphorus distribution. We further analyzed their potential change in floodplains under various conditions, determining the sedimentation and mineralization process of phosphorus. Meanwhile, phosphorus in the sediment will experience dynamic fluctuation as a source or sink of fluvial floodplains based on varying factors, including hydrological conditions, climate variations, biological activity, and pedological characteristics. In particular, the productivity and community population in floodplains, like vegetation and fishes, will be primarily associated with the periodic changes in phosphorus through food chain. Lastly, this review provided corresponding perspectives on improving the phosphorus administration in river floodplains based on existing problems. In total, it is anticipated that it will enhance the understanding of phosphorus resources or sink in the fluvial floodplains, contributing to the stability of aquatic ecosystems.
Review
09 January 2025Recent Advancements in Alumina-Based High-Temperature Insulating Materials: Properties, Applications, and Future Perspectives
As a high-temperature thermal insulation material with excellent mechanical properties, alumina (Al2O3)-based materials hold significant potential for applications in aerospace, advanced manufacturing, automobiles, industrial furnaces, and other fields. However, the inherent brittleness of alumina poses a limitation to its wider application. Therefore, there is a pressing need to develop alumina-based materials that offer high toughness while retaining superior mechanical properties. This paper begins by exploring the structure of alumina, highlighting its thermal conductivity, insulation, and mechanical properties in high-temperature environments. It then reviews the classification and synthesis methods of alumina-based materials, along with the latest advances in design strategies. Notably, the rational design of alumina composition, structure, and morphology is emphasized as crucial for optimizing material performance, thereby supporting the industrial development and application of these materials in high-tech sectors. Finally, the paper discusses the challenges and evolution of alumina-based materials in real-world industrial applications and suggests potential directions for future development.
Article
09 January 2025Sustainability Practices and Financial Performance: Evidence from BIST Electricity Index
Amidst the backdrop of heightened market risks associated with transitioning to a lower-carbon economy, this study pioneers an examination of the correlation between sustainability and financial performance within Turkish energy market generator and retailer companies. In this study, the sustainability performance, exposure to market risks and effects on the financial performance of sub-sectors of companies listed in the BIST Electricity index were analyzed using panel data regression. The findings reveal a nuanced relationship between sustainability factors and financial performance, underscoring the imperative for electricity sector companies to prioritize sustainability initiatives not only for ethical reasons but also as a strategic imperative for long-term financial success and stakeholder value creation. Finally, the possibility of impending regulatory changes underscores the importance of early adoption of sustainability practices to mitigate potential financial liabilities and navigate future market risks effectively.
