Search Results (87)

A continuous mixing process with a twin-screw extruder was investigated for graphite-based negative electrode pastes for high-power applications. In the extrusion-based mixing process, the first kneading concentration is one of the key processing parameters for systematic optimization of relevant electrode paste properties like viscosity and particle size distribution. For different active materials at a constant electrode paste composition, a clear correlation of increasing kneading concentration with decreasing viscosity can be observed up to a certain reversal point, initiating a change in the trend and the rheological behavior, thus indicating a process limit. The fundamental effects causing this change and the associated impact on materials and battery performance were evaluated by applying further analytical methods and electrochemical characterization. It is revealed that the change in viscosity is associated with enhanced de-agglomeration of the carbon black additive and with partial particle grinding of the active material and thus a partial change in the interlayer distance of graphene layers and, correspondingly, the electrochemical behavior of the active material. Beyond this, correlations between processing parameters and product properties are presented. Furthermore, indicators are suggested with which monitoring of the machine parameters enables the detection of changes in the electrode paste characteristics. Full article

An ultrasonic-enhanced hydrogen peroxide water-washing process was developed to recover lead from raw flue dust (RFD) under neutral conditions. At optimal parameters (40 °C, 30 min, 4 mL H₂O₂, liquid-to-solid ratio 2:1, 240 W ultrasound), the Pb mass fraction in the solid residue increased from 41.68% in the RFD to 68.11%, accompanied by a Pb recovery rate of 97.1%. These values are significantly higher than those obtained under identical conditions without ultrasound (64.07% and 95.93%, respectively). Ultrasound promotes de-agglomeration and generates •OH radicals that accelerate the oxidation of PbSO₃ to insoluble PbSO₄ while concurrently removing impurity cadmium. This research offers a green and efficient alternative to traditional lead recovery methods, fostering sustainable development in the metallurgical industry. Full article

This study investigates the role of the digital economy (DE) in advancing the high-quality development of manufacturing in China, with a particular focus on the moderating effects of manufacturing agglomeration and digital literacy. Using provincial panel data from 2013 to 2023, we find that the digital economy significantly enhances manufacturing development across three key dimensions: green transformation, innovation, and high-end industrial upgrading. Manufacturing agglomeration strengthens this effect, especially in the Eastern and Western regions, by facilitating digital spillovers and leveraging digital infrastructure. However, in the Central region, the impact of agglomeration is weaker, hindered by fragmented industrial clusters and underdeveloped digital infrastructure. The study also highlights significant regional differences in the moderating effect of digital literacy. In the Eastern region, digital literacy negatively moderates the relationship between DE and manufacturing development due to skill mismatches, while in the Western region, localized concentrations of digital skills have a positive but geographically constrained impact. Temporal analysis reveals a shift in the moderating role of digital literacy, with its negative effect becoming more pronounced after 2018, suggesting a growing need for targeted skill development policies. These findings underscore the importance of regionally tailored strategies to promote digital manufacturing integration, with a focus on sustainable development through digital transformation and green manufacturing practices. Full article

This report introduces a high-performance bimetallic electrocatalyst for the oxygen reduction reaction (ORR) featuring a 20 wt.% platinum content. The PtCu-based catalyst combines de-alloyed nanoparticles (NPs) supported on nitrogen-doped carbon. Enhanced uniformity in NP distribution significantly boosts the catalyst performance. Nitrogen-doped carbon provides active centers for NP deposition, which is confirmed by HAADF-STEM and EDX. The PtCu/CN catalyst achieves over 5.6 times the ORR mass activity and two times the stability under pulse cycling compared to commercial Pt/C. Uniquely, the study examines bimetallic NPs and local nano-sites before and after stress testing using IL-TEM. In situ analysis of PtCu/CN microstructure revealed two primary degradation mechanisms, (i) partial dissolution of NPs and (ii) NP agglomeration, with the C–N support significantly mitigating these effects through strong NP–support interactions. The findings underscore the prospects of bimetallic PtCu catalysts with nitrogen-doped support by showcasing exceptional ORR activity and durability. Full article

High-density cities have obvious characteristics of compact urban spatial form and intensive land use in terms of spatial environment, and have always been a topic of academic focus. As a typical coastal historical district, the Macau Peninsula pier district (mainly the Macau Inner Harbour) has a high building density and a low average street width, forming a vertical coastline development model that directly converses with the ocean. This area is adjacent to Macau’s World Heritage Site and directly related to the Marine trade functions. The distribution pattern of cultural heritage linked by the ocean has strengthened Macau’s unique positioning as a node city on the Maritime Silk Road. This text is based on the theory of urban development, integrates spatial syntax and POI analysis techniques, and combines the theories of waterfront regeneration, high-density urban form and post-industrial urbanism to integrate and deepen the theoretical framework, and conduct a systematic study on the urban spatial characteristics of the coastal area of the Macau Peninsula. This study found that (1) Catering and shopping facilities present a dual agglomeration mechanism of “tourism-driven + commercial core”, with Avenida de Almeida Ribeiro as the main axis and radiating to the Ruins of St. Paul’s and Praça de Ponte e Horta, respectively. Historical blocks and tourist hotspots clearly guide the spatial center of gravity. (2) Residential and life service facilities are highly coupled, reflecting the spatial logic of “work-residence integration-service coordination”. The distribution of life service facilities basically overlaps with the high-density residential area, forming an obvious “living circle + community unit” structure with clear spatial boundaries. (3) Commercial and transportation facilities form a “functional axis belt” organizational structure along the main road, with the Rua das Lorchas—Rua do Almirante Sérgio axis as the skeleton, constructing a “functional transmission chain”. (4) The spatial system of the Macau Peninsula pier district has transformed from a single center to a multi-node, network-linked structure. Its internal spatial differentiation is not only constrained by traditional land use functions but is also driven by complex factors such as tourism economy, residential migration, historical protection, and infrastructure accessibility. (5) Through the analysis of space syntax, it is found that the core integration of the Macau Peninsula pier district is concentrated near Pier 16 and the northern area. The two main roads have good accessibility for motor vehicle travel, and the northern area of the Macau Peninsula pier district has good accessibility for long and short-distance walking. Full article

This study presents an innovative, eco-friendly approach for converting waste zeolite dust into efficient petroleum sorbents through an integrated agglomeration–deagglomeration process using high-pressure grinding rolls (HPGRs). This method generates secondary porosity without calcination, enhancing sorption while reducing greenhouse gas emissions and supporting sustainable development by valorizing industrial by-products for environmental remediation. The study aimed to assess the influence of binder and water content on petroleum sorption performance, textural properties, and mechanical strength of the produced sorbents, and to identify correlations between these parameters. Sorbents were characterized using mercury porosimetry (MIP), sorption measurements, mechanical resistance tests, scanning electron microscopy (SEM), and digital microscopy. Produced zeolite sorbents (0.5–1 mm) exceeded the 50 wt.% sorption threshold required for oil spill cleanup in Poland, outperforming diatomite sorbents by 15–50% for diesel and 40% for used engine oil. The most effective sample, 3/w/22.5, reached capacities of 0.4 g/g for petrol, 0.8 g/g for diesel, and 0.3 g/g for used oil. The sorption mechanism was governed by physical processes, mainly diffusion of nonpolar molecules into meso- and macropores via van der Waals forces. Sorbents with dominant pores (~4.8 µm) showed ~15% higher efficiency than those with smaller pores (~0.035 µm). The sorbents demonstrated amphiphilic behavior, enabling simultaneous uptake of polar (water) and nonpolar (petrochemical) substances. Full article

This study investigates the effect of potassium (K) promotion on Pt/m-ZrO₂ catalysts in methanol steam reforming (MSR), revealing critical insights into reaction pathways and catalyst performance. While increasing K loading reduces catalytic activity, it selectively enhances the hydrogen-producing formate dehydrogenation and de-carboxylation pathway. Structural analyses using HR-TEM and DRIFTS show that higher K concentrations block Pt sites and promote agglomeration, reshaping catalytic behavior. Notably, the 3.1% K-promoted catalyst achieves high stability at 358 °C, with a CO₂ selectivity exceeding 80% and minimal methane formation, outperforming the unpromoted catalyst in terms of CO and CH₄ selectivity. Temperature studies further demonstrate reduced CO selectivity at higher temperatures, highlighting distinct advantages of K-doped catalysts. These findings underscore the role of K in enhancing surface basicity and its impact on formate interaction, offering valuable insights for optimizing MSR catalysts and advancing hydrogen production technologies. Full article

Submicron particles are widely used in industrial applications due to their unique physical and mechanical properties that enhance the performance of composite materials. In particular, boron carbide particles are valued for their exceptional hardness and high wear resistance and are especially valuable in protective coatings and aerospace applications. However, these particles can agglomerate, significantly impairing their effectiveness. When this occurs during the development of composite materials, physical and mechanical properties are negatively affected. In this paper, a chemical-free method using a non-destructive, open-system dry mechanical deagglomeration technique is developed, leaving the primary particles unaltered, while breaking up strong adhesions between primary particles resulting from the manufacturing process. This method was tested for the deagglomeration of as-received boron carbide submicron particles, with an average primary particle diameter of d₅₀ = 300 nm, and its effect on particle size distribution is presented. Furthermore, X-ray diffraction and true density measurements were carried out on the raw powder. Submicron particles in the dry and as-received state were poured into an experimental mold without a dispersing agent or a protective atmosphere. Static pressure was applied up to 141 MPa to produce tablets at room temperature, finding that 70 MPa yielded the best results in terms of homogeneity, dispersibility, and reproducibility. In order to break apart the densified pressed tablets, ultrasonication was applied before running particle size measurements in the wet dispersed state. Using a tri-laser diffraction light scattering technique, it was determined that particle size distribution followed a Gaussian curve, indicating that this method is suitable to regain the primary submicron particles with uniform properties. It is also shown that applying ultrasound on the as-received powder alone failed to cause the complete deagglomeration of strongly adhering primary particles. These findings suggest that there is no significant wear on the primary particles and no alteration of their surface chemistry, due to the lack of any chemically supported mechanisms such as the alteration of surface charge or the adsorption of surfactants. Furthermore, as the static pressure exerts an immediate impact on all particles in the mold, there is a clear economical advantage in terms of a shorter processing time over other deagglomeration methods such as high shear mixing. Full article

The digital economy (DE) and real economy (RE) are dual pillars of the modern economic system. The deep integration of the digital economy and real economy (IDR) has emerged as a pivotal strategic trend. IDR not only can enhance international competitiveness but also contributes to sustainable development goals. This work collects DE and RE data from 30 provinces in China between 2012 and 2022. The entropy weight method and the coupling coordination degree (CCD) model are employed to measure the level of IDR. Furthermore, the Dagum Gini coefficient, Kernel density estimation, the spatial autocorrelation model, and the geographically and temporally weighted regression (GTWR) model are utilized to analyze the spatial–temporal evolution and influencing factors of CCD. The following conclusions are drawn: (1) During the study period, CCD shows an upward trend, but the value is relatively low. (2) There are significant spatial differences in CCD, and the inter-regional difference is the primary cause. (3) The regional differences in CCD are continuously widening. (4) CCD shows an obvious global spatial agglomeration feature, and the spatial agglomeration degree of CCD has been enhanced from 2012 to 2022. (5) The policy intensity, digital infrastructure, industrial structure, human capital, technological innovation, and market environment have significant impacts on CCD. The obtained findings provide important theoretical support for the coordinated development of DE and RE. Full article

In recent years, the employment of rejuvenators and warm mix asphalt (WMA) additives for reclaimed asphalt pavement (RAP) has been recognized as a popular approach to increase the recycling rate of waste materials and promote the sustainable development of pavement engineering. However, the composition of warm mix recycled asphalt binder is complicated, and the microstructural changes brought about by the rejuvenators and WMA additives are critical in determining its macroscopic mechanical properties. This research focuses on the atomic modeling of the rejuvenators and WMA additives diffusion behavior of the warm mix recycled asphalt binder. The objective is to reveal the thermodynamic performance and diffusion mechanism of the WMA binder under the dual presence of rejuvenators and WMA additives. Three types of mutual diffusion systems (Aged and oil + virgin + wax, Aged + virgin + wax, and Aged and oil + virgin) were established, respectively, for a comparative investigation of the glass transition temperature, viscosity, thermodynamics, free volume, and diffusion behavior. The results indicate a 44.27% and 31.33% decrease in the glass transition temperature and apparent viscosity, respectively, after the incorporation of 5% oil rejuvenators in the Aged + virgin + wax asphalt binder, demonstrating the improved cracking resistance and construction workability. The presence of the RAP binder and organic WMA additives raised the cohesion of the asphalt binder and decreased self-healing ability and free volume, and these detrimental influences can be offset by the introduction of rejuvenators. The combined use of rejuvenators and organic WMA additives remarkably enhanced the de-agglomeration to asphaltenes, stimulated the activity of aged RAP macromolecular components, and ultimately improved the blending efficiency of virgin binders with the overall structure of RAP binders. Full article

A novel magnesium (Mg)-based metal matrix nanocomposite (MMNC) was fabricated using ultrasonic melt treatment to promote the de-agglomeration of the bioactive glass–ceramic nanoparticles and the homogenization of the melt. The cast samples were then heat treated, machined, and hot rolled to reduce grain size and remove structural defects. Standard mechanical and electrochemical tests were conducted to determine the effect of fabrication and processing on the mechanical and corrosion properties of MMNCs. Compression tests, potentiodynamic polarization tests, electrochemical impedance spectroscopy, and static immersion testing were conducted to determine the characteristics of the MMNCs. The results showed that the combination of ultrasonic melt processing and thermomechanical processing caused the corrosion rate to increase from 8.7 mmpy after 10 days of immersion to 22.25 mmpy when compared with the ultrasonicated MMNCs but remained stable throughout the immersion time, showing no statistically significant change during the incubation periods. These samples also experienced increased yield stress (135.5 MPa) and decreased elongation at break (21.92%) due to the significant amount of grain refinement compared to the ultrasonicated MMNC (${\mathsf{\sigma }}_{\mathrm{Y}}$ = 59.6 MPa, elongation = 40.44%). The MMNCs that underwent ultrasonic melt treatment also exhibited significant differences in the corrosion rate calculated from immersion tests. Full article

The fluidized bed is a critical reactor in the energy and chemical industries, where the mixing and agglomeration behaviors of binary particles significantly influence both the efficiency of reaction processes and the uniformity of final products. However, the selection of appropriate drag force models remains a subject of debate due to the variability in particle properties and operating conditions. In this study, we investigated the fluidization behavior of binary mixtures composed of two different sizes of Geldart-D particles within a fluidized bed, evaluating nine distinct drag force models, including Wen and Yu; Schiller and Naumann; Ergun; Gidaspow, Bezburuah, and Ding; Huilin and Gidaspow; De Felice; Syamlal and O’Brien; and Hill, Koch, and Ladd. We focused on four key parameters: particle mixing degree, migration characteristics, temperature variation, and mean pressure drop. Simulation results revealed that the choice of drag model markedly affected mixing behavior, migration dynamics, and temperature distribution. Notably, the Ergun; Gidaspow, Bezburuah, and Ding; and Hill, Koch, and Ladd models exhibited superior particle mixing uniformity. While the drag model had a relatively minor impact on particle temperature changes, its selection became critical in simulations requiring high-temperature precision. Regarding pressure drop, the Huilin and Gidaspow and Gidaspow, Bezburuah, and Ding models demonstrated smaller and more stable pressure drop fluctuations. These findings offer valuable theoretical insights into gas–solid two-phase flow under binary particle mixing and provide practical guidance for the design and operation of fluidized bed reactors. Full article

The semiconductor industry is a pivotal hub in the global information sector, in which superpowers compete for technological dominance. As a strategic, leading, and foundational sector, it is vital for advancing China’s manufacturing ambitions through new waves of transformation and upgrades. Therefore, of particular concern is the crisis surrounding China’s semiconductor supply chain insecurity and the intensifying U.S. sanctions on China’s high-tech companies. As such, in this study, we utilize data from China’s semiconductor enterprises, investments, and related statistics from 2002 to 2020; industrial agglomeration indicators; and a social network analysis to examine the spatiotemporal pattern, industrial agglomeration, and investment networks of six key value chain segments: wafer materials, packaging materials, semiconductor equipment, integrated circuit (IC) design, manufacturing, and testing/packaging. The research focuses on how these sectors can contribute to sustainable growth and economic responsibility within China’s semiconductor industry. Accordingly, the core questions explored were as follows: what are the provincial-level spatial production dynamics and evolutionary characteristics within China’s semiconductor industry, and how do the inter-provincial investment patterns manifest? The findings reveal the following: (1) The findings reveal a strong concentration of firms in the Eastern Coastal region, particularly in Jiangsu, Shanghai, Zhejiang, and Guangdong. Additionally, IC design exhibits the highest clustering, and other segments such as wafer materials, manufacturing, and packaging/testing are relatively concentrated, whereas equipment distribution is more dispersed. (2) The industry expanded steadily from 2002 to 2013, with a rapid expansion from 2014 to 2020, particularly in Guangdong. (3) Investment patterns are characterized by local and regional focus, strongly influenced by geographical proximity. This study aims to reveal the geographic concentration patterns of China’s semiconductor industry and to explore its investment networks. The findings are intended to provide theoretical support for optimizing sustainable industrial layouts, promoting sustainable industrial practices, and guiding policy formulation. Furthermore, in the broader context of de-globalization, this study offers insights and recommendations for strengthening industrial autonomy and sustainability in response to external challenges, thereby contributing to the sustainable development of a more robust domestic semiconductor supply chain. These insights are particularly significant in safeguarding China’s technological independence and future economic stability amid global tensions. Furthermore, by integrating sustainability into its semiconductor industry, China can create a more resilient, self-sufficient, and environmentally responsible industrial sector, capable of meeting both domestic and global demands. As China continues to expand its semiconductor industry, incorporating sustainable development principles will be essential for long-term success. The sustainable practices not only ensures compliance with environmental regulations but also enhances industrial competitiveness, promotes green techniques and contributes to broader societal goals. This aligns with China’s broader ambitions for sustainable development and positions the country as a key player in the global green technology revolution. Full article

This study investigates the equilibrium state diagram of maltodextrins with varying dextrose equivalents (DE 10 and 30) for quercetin microencapsulation. Using XRD, SEM, and optical microscopy, three transition regions were identified: amorphous (a_w 0.07–0.437), semicrystalline (a_w 0.437–0.739), and crystalline (a_w > 0.739). In the amorphous region, microparticles exhibit a spherical morphology and a fluffy, pale-yellow appearance, with Tg values ranging from 44 to −7 °C. The semicrystalline region shows low-intensity diffraction peaks, merged spherical particles, and agglomerated, intense yellow appearance, with Tg values below 2 °C. The crystalline region is characterized by fully collapsed microstructures and a continuous, solid material with intense yellow color. Optimal storage conditions are within the amorphous region at 25 °C, a_w 0.437, and a water content of 1.98 g H₂O per g of dry powder. Strict moisture control is required at higher storage temperatures (up to 50 °C) to prevent microstructural changes. This research enhances understanding of maltodextrin behavior across diverse dextrose equivalents, aiding the development of stable microencapsulated products. Full article

Waste carbon fibers as reinforcing elements in construction materials have recently gained increasing interest from researchers, providing outstanding strength performance and a lower environmental footprint compared to virgin fibers. Combination with cement-free binders, namely alkali-activated materials, is becoming increasingly important for sustainable development in the construction industry. This paper presents results relating to the potential use of waste carbon fibers in alkali-activated mortars. The waste carbon fiber fraction utilized in this research is difficult to integrate as reinforcement in ceramic–cementitious matrices due to its agglomerated form and chemical inertness. For this reason, a nanoceramic coating pretreatment based on nanoclay has been implemented to attempt improvements in terms of deagglomeration, dispersibility, and compatibility with alkali-activated materials. After chemical–physical and microstructural analysis on the nanoclay-plated fibers (including X-ray diffraction, IR spectroscopy, contact angle measurements, and electron microscopy) mortars were produced with four different dosages of treated and untreated waste fibers (0.25 wt.%, 0.5 wt.%, 0.75 wt.%, and 1 wt.%). Mechanical tests and fractographic investigations were then performed. The nanoclay coating interacts compatibly with the waste carbon fibers and increases their degree of hydrophilicity to improve their deagglomeration and dispersion. Compared to the samples incorporating as-received fillers, the addition of nanoclay-coated fibers improved the strength behavior of the mortars, recording a maximum increase in flexural strength of 19% for a fiber content of 0.25 wt.%. This formulation is the only one providing an improvement in mechanical behavior compared to unreinforced mortar. Indeed, as the fibrous reinforcement content increases, the effect of the nanoclay is attenuated by mitigating the improvement in mechanical performance. Full article