Search Results (7,990)

The preparation and use of iron oxide magnetic nanoparticles for water remediation is a widely investigated research field. To improve the efficacy of such nanomaterials, different synthetic processes and functionalization methods have been developed in the framework of green chemistry to exploit their magnetic properties and adsorption capacity in a sustainable way. In this work, iron oxide magnetic nanoparticles embedded in cross-linked sodium alginate beads designed to clean water from metal ions were magnetically characterized. In particular, the effect of copper adsorption on their magnetic properties was investigated. The magnetic characterization in a DC field of the beads before adsorption showed the presence of a superparamagnetic state at 300 K—a state that was also preserved after copper adsorption. The main differences in terms of magnetic properties before and after Cu²⁺ adsorption were the reduction of the magnetic signal (observed by comparing the saturation magnetization) and a different shape of the blocking temperature distribution obtained by magnetization versus temperature measurements. The evaluation of the reduction in magnetization can be important from the application perspective since it can affect the efficiency of the beads’ removal from the water medium after treatment. Full article

This study investigates the sustainable production of NdFeB permanent magnets using powder extrusion molding (PEM) with in situ magnetic alignment, utilizing recycled powder from an end-of-life (Eol) wind turbine magnet obtained via hydrogen processing of magnetic scrap (HPMS). Finite Element Method (FEM) simulations were conducted to design and optimize alignment tool geometries and magnetic field parameters. A key challenge in the PEM process is achieving effective particle alignment while the continuous strand moves through the magnetic field during extrusion. To address this, extrusion experiments were performed using three different alignment tool geometries and varying magnetic field strengths to determine the optimal configuration for particle alignment. The experimental results demonstrate a high degree of alignment (B_r/J_s = 0.95), exceeding the values obtained with PEM without an external magnetic field (0.78). The study confirms that optimizing the alignment tool geometry and applying sufficiently strong magnetic fields during extrusion enable the production of anisotropic NdFeB permanent magnets without post-machining, providing a scalable route for permanent magnet recycling and manufacturing. Moreover, PEM with in situ magnetic particle alignment allows for the continuous fabrication of near-net-shape strands with customizable cross-sections, making it a scalable approach for permanent magnet recycling and industrial manufacturing. Full article

This article investigates the role of space in the fiction of Jeffrey Eugenides, focusing on The Virgin Suicides (1993) and Middlesex (2002) through the lens of spatial theory. Drawing on key thinkers such as Henri Lefebvre, Michel Foucault, Edward Soja, Yi-Fu Tuan, and Doreen Massey, the study explores how Eugenides constructs spatial environments that not only frame but actively shape the identities, desires, and traumas of his characters. In The Virgin Suicides, suburban domestic spaces are shown to function as heterotopias—sites of surveillance, repression, and mythologized femininity—while Middlesex engages with transnational and urban spaces to narrate diasporic and intersex identity as dynamic, embodied, and liminal. The analysis reveals that Eugenides uses space as both a narrative device and a thematic concern to interrogate gender, memory, and power. Rather than passive backdrops, the novelistic spaces become charged arenas of conflict and transformation, reflecting and resisting dominant socio-cultural discourses. This study argues that space in Eugenides’ fiction operates as a critical register for understanding the politics of belonging and the production of subjectivity. By situating Eugenides within the broader field of literary spatiality, this article contributes to contemporary debates in literary geography, gender studies, and American fiction. Full article

In the present work, the optimization of ceramic-based composite WC(Co,Ni) welds by laser cladding was carried out using response surface methodology based on finite element analysis. The heat distribution and temperature field of laser-melted WC(Co,Ni) ceramic coatings were simulated using ANSYS software, which allowed the computation of the distribution of residual stresses. The results show that the isotherms in the simulation of the temperature field are elliptical in shape, and that the isotherms in front of the moving heat source are dense with a larger temperature gradient, while the isotherms behind the heat source are sparse with a smaller temperature gradient. In addition, the observed microstructural evolution shows that the melting zone domains of WC(Co,Ni) are mainly composed of unmelted carbides. These carbides are dendritic, rod-like, leaf-like, or net-like, and are agglomerated into smaller groups. The W content of these unmelted carbides exceeds 80%, while the C content is around 1.5–3.0%. The grey areas are composed of WC, Co and Ni compounds. Based on the regression model, a quadratic model was successfully constructed. A three-dimensional profile model of the residual stress behaviour was further explored. The estimated values of the RSM-based FEA model for residual stress are very similar to the actual results, which shows that the model is effective in reducing residual stress by laser cladding. Full article

Road markings, as critical components of transportation infrastructure, are crucial for ensuring traffic safety. Accurate quantification of their damage severity is vital for effective maintenance prioritization. However, existing methods are limited to detecting the presence of damage without assessing its extent. To address this limitation, we propose a novel segmentation-based framework for estimating the degree of road marking damage. The method comprises two stages: segmentation of residual pixels from the damaged markings and segmentation of the intact markings region. This dual-segmentation strategy enables precise reconstruction and comparison for severity estimation. To enhance segmentation performance, we proposed two key modules: the Asymmetric Large Field-of-View Contextual (ALFVC) module, which captures rich multi-scale contextual features, and the supervised Boundary Feature Enhancement (BFE) module, which strengthens shape representation and boundary accuracy. The experimental results demonstrate that our method achieved an average segmentation accuracy of 89.44%, outperforming the baseline by 5.86 percentage points. Moreover, the damage quantification achieved a minimum error rate of just 0.22% on the proprietary dataset. The proposed approach was both effective and lightweight, providing valuable support for automated maintenance planning, and significantly improving the efficiency and precision of road marking management. Full article

In recent years, digital microfluidic biochips (DMFBs), based on microfluidic technology, have attracted attention as compact and flexible experimental devices. DMFBs are widely applied in biochemistry and medical fields, including point-of-care clinical diagnostics and PCR testing. Among them, micro electrode dot array (MEDA) biochips, composed of numerous microelectrodes, have overcome the limitations of conventional chips by enabling finer droplet manipulation and real-time sensing, thus significantly improving experimental efficiency. While various studies have been conducted to enhance the utilization of MEDA biochips, few have considered the shape-dependent velocity characteristics of droplets in routing. Moreover, methods that do take such characteristics into account often face significant challenges in solving time. This study proposes a fast droplet routing method for MEDA biochips that incorporates shape-dependent velocity characteristics by utilizing the distance information to the target cell. The experimental results demonstrate that the proposed method achieves approximately a 67.5% reduction in solving time compared to existing methods, without compromising solution quality. Full article

Accurately identifying coherent vortex structures (CVSs) in backward-facing step (BFS) flows remains a challenge, particularly in reconciling visual streamlines with mathematical criteria. In this study, high-resolution velocity fields were captured using particle image velocimetry (PIV) in a pressurized BFS setup. Instantaneous streamlines reveal distinct spiral patterns, vortex centers, and saddle points, consistent with physical definitions of vortices and offering intuitive guidance for CVS detection. However, conventional vortex identification methods often fail to reproduce these visual features. To address this, an improved Q-criterion method is proposed, based on the normalization of the velocity gradient tensor. This approach enhances the rotational contribution while suppressing shear effects, leading to improved agreement in vortex position and shape with those observed in streamlines. While the normalization process alters the representation of physical vortex strength, the method bridges qualitative visualization and quantitative analysis. This streamline-consistent identification framework facilitates robust CVS detection in separated flows and supports further investigations in vortex dynamics and turbulence control. Full article

Oil spill simulation models are essential for predicting the oil spill behavior and movement in marine environments. In this study, we comprehensively reviewed a large and diverse body of peer-reviewed literature obtained from Scopus and Web of Science. Our initial analysis phase focused on examining trends in scientific publications, utilizing the complete dataset derived after systematic screening and database integration. In the second phase, we applied elements of a systematic review to identify and evaluate the most influential contributions in the scientific field of oil spill simulations. Our analysis revealed a steady and accelerating growth of research activity over the past five decades, with a particularly notable expansion in the last two. The field has also experienced a marked increase in collaborative practices, including a rise in international co-authorship and multi-authored contributions, reflecting a more global and interdisciplinary research landscape. We cataloged the key modeling frameworks that have shaped the field from established systems such as OSCAR, OIL-MAP/SIMAP, and GNOME to emerging hybrid and Lagrangian approaches. Hydrodynamic models were consistently central, often integrated with biogeochemical, wave, atmospheric, and oil-spill-specific modules. Environmental variables such as wind, ocean currents, and temperature were frequently used to drive model behavior. Geographically, research has concentrated on ecologically and economically sensitive coastal and marine regions. We conclude that future progress will rely on the real-time integration of high-resolution environmental data streams, the development of machine-learning-based surrogate models to accelerate computations, and the incorporation of advanced biodegradation and weathering mechanisms supported by experimental data. These advancements are expected to enhance the accuracy, responsiveness, and operational value of oil spill modeling tools, supporting environmental monitoring and emergency response. Full article

Understanding the entrepreneurial profile is essential for developing effective regional policies that promote business growth. The path of an entrepreneur is shaped not only by individual decisions but also by the inherent risks of managing a business. This study aims to identify the characteristics of entrepreneurs at the regional level, specifically highlighting the impact of accumulated experience in their fields. Our central hypothesis asserts that entrepreneurial experience significantly influences how business owners perceive and respond to economic challenges. Utilizing survey data from 120 entrepreneurs in Romania’s Center Region (a NUTS 2 area), we reveal that entrepreneurial experience profoundly affects perceptions of key business challenges, such as legislative instability, taxation predictability, governmental support strategies, and access to SME financing. Importantly, our findings demonstrate that entrepreneurs with less than 10 years of experience express greater concerns about these challenges compared to their more seasoned peers. This novel insight highlights the need for tailored policy interventions aimed at enhancing regional economic resilience and fostering entrepreneurial sustainability. By addressing the specific needs of less experienced entrepreneurs, our study contributes to a deeper understanding of how experience shapes business dynamics in the region. Full article

This study reports the synthesis and evaluation of iron molybdate (Fe₂(MoO₄)₃) and iron tungstate (FeWO₄) as photocatalysts for the degradation of a real industrial effluent from aluminum anodizing processes under visible light irradiation. The oxides were synthesized via a co-precipitation method in an aqueous medium, followed by microwave-assisted hydrothermal treatment. Structural and morphological characterizations were performed using X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, ultraviolet–visible (UV–vis), and photoluminescence (PL) spectroscopies. The effluent was characterized by means of ionic chromatography, total organic carbon (TOC) analysis, physicochemical parameters (pH and conductivity), and UV–vis spectroscopy. Both materials exhibited well-crystallized structures with distinct morphologies: Fe₂(MoO₄)₃ presented well-defined exposed (001) and (110) surfaces, while FeWO₄ showed a highly porous, fluffy texture with irregularly shaped particles. In addition to morphology, both materials exhibited narrow bandgaps—2.11 eV for Fe₂(MoO₄)₃ and 2.03 eV for FeWO₄. PL analysis revealed deep defects in Fe₂(MoO₄)₃ and shallow defects in FeWO₄, which can influence the generation and lifetime of reactive oxygen species. These combined structural, electronic, and morphological features significantly affected their photocatalytic performance. TOC measurements revealed degradation efficiencies of 32.2% for Fe₂(MoO₄)₃ and 45.3% for FeWO₄ after 120 min of irradiation. The results highlight the critical role of morphology, optical properties, and defect structures in governing photocatalytic activity and reinforce the potential of these simple iron-based oxides for real wastewater treatment applications. Full article

The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic health. The aim of this review is therefore to provide an overview of the interactions between oral and gut microbiota, and the influence of diet and related metabolites on this axis. Pathogenic oral bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, can migrate to the gut through the enteral route, particularly in individuals with weakened gastrointestinal defenses or conditions like gastroesophageal reflux disease, contributing to disorders like inflammatory bowel disease and colorectal cancer. Bile acids, altered by gut microbes, also play a significant role in modulating these microbiota interactions and inflammatory responses. Oral bacteria can also spread via the bloodstream, promoting systemic inflammation and worsening some conditions like cardiovascular disease. Translocation of microorganisms can also take place from the gut to the oral cavity through fecal–oral transmission, especially within poor sanitary conditions. Some metabolites including short-chain fatty acids, trimethylamine N-oxide, indole and its derivatives, bile acids, and lipopolysaccharides produced by both oral and gut microbes seem to play central roles in mediating oral–gut interactions. The complex interplay between oral and gut microbiota underscores their crucial role in maintaining systemic health and highlights the potential consequences of dysbiosis at both the oral and gastrointestinal level. Some dietary patterns and nutritional compounds including probiotics and prebiotics seem to exert beneficial effects both on oral and gut microbiota eubiosis. A better understanding of these microbial interactions could therefore pave the way for the prevention and management of systemic conditions, improving overall health outcomes. Full article

Enhancing the nutritional content of crops is crucial for safeguarding human health and mitigating global hunger. A viable method for attaining this goal is the planned implementation of various agronomic practices, including tillage and nutrient provision. A field experiment was executed at the Hungarian University of Agriculture and Life Sciences in Gödöllő in the 2023 and 2024 growing seasons. The study aimed to assess the effects of foliar nutrient supply and soil tillage methods on the grain nutritional composition and mineral content of winter barley. Employing a split-plot design with three replications, the experiment included four nutrient treatments (control, bio-cereal, bio-algae, and MgSMnZn blend) and two soil tillage types (i.e., plowing and cultivator). The results indicated that while protein content was not influenced by the main effects of nutrients and tillage, the levels of β-glucan, starch, crude ash, and moisture content were significantly (p < 0.05) affected by the nutrient treatments and by growing year, treated as a random factor. Notably, bio-algae and bio-cereal nutrients, combined with cultivator tillage, enhanced β-glucan content. All applied nutrient treatments increased the level of starch compared to the control. With regard to grain mineral content, the iron and zinc content responded to the nutrient supply, tillage, and growing year. However, applying a multiple-nutrient composition-based treatment did not increase iron and zinc levels, suggesting that individual applications may be more effective for increasing the content of these minerals in grains. Cultivator tillage improved iron and zinc levels. Moreover, manganese (Mn) and copper (Cu) were predominantly affected by nutrient availability and by growing seasons as a random factor. Therefore, to improve grain quality, this study emphasizes the significance of proper nutrient and tillage methods by focusing on the intricate relationships between agronomic techniques and environmental factors that shape barley’s nutritional profile. Full article

This paper presents an ethnographically informed analysis of research in Cairo and Sharm El-Sheikh (Egypt) surrounding the 2022 United Nations Framework Convention on Climate Change (UNFCCC) Conference of Parties (COP27) summit. I discuss the geopolitics and geopolitical disruptions of researching activism and activist lives in politically sensitive environments. As shown here, developing new methodological interventions plays a crucial role in understanding contextual methodological limitations, dealing with logistical challenges, and building authentic relationships with research participants. Here, I introduce counter-interviews as a methodological strategy to build trust and invest in researcher–participant relationships. This article draws on participant observation, conversations with environmental and climate activists and non-activists in Cairo prior to and after COP27 and in Sharm El-Sheikh during the second week of the summit, reflective field notes, and 20 semi-structured interviews conducted online between February and August 2023. Here, I use the term “environmental non-activism” to draw attention to the sensitivity, complexity, and fragility of political or apolitical environmental and climate action in an authoritarian context where any form of collective action is highly monitored, regulated, and sometimes criminalized by the state. The main argument of this paper is that examining interlocking power dynamics that shape and reshape the activist space in relation to the state is a requirement for understanding and researching the complexities and specificities of climate activism and non-activism in authoritarian contexts. Along with this argument, this paper invites climate education researchers to reevaluate what non-movements and non-activists in the Global South offer to their analyses of possible alternatives, socio-political change, and politics of hope (and to the broader field of activism in educational research, where commitment to disruption, refusal, and subversion play a key role. Full article

This study was conducted in the context of China’s latest “double carbon” policy. The objective of this study was twofold: firstly, to examine the characteristics of traditional Chinese residential skywell; and secondly, to investigate and develop climate-adaptive technologies for these structures. To this end, a study was conducted on the Huizhou skywell architecture in China. Firstly, we obtained a large amount of basic data, such as traditional buildings and skywell parameters in Huizhou through field research and on-site mapping. Second, we combined a large number of parameters and typical cases to analyze the data and determine a more scientifically typical model of Huizhou architecture and experimental coverage of skywell data. Different shapes and sizes of skywell were formed by changing the combination of skywell length and width, and the indoor wind environments of these skywell dwelling models were simulated one by one using PHOENIX (v2016) software. Finally, the data obtained from these simulations are analyzed using the variable control method, and the simulated indoor wind environments of skywells under different scale combinations in terms of skywell length, width, and length–width coupling effects are summarized and compared. The following conclusions were drawn: (1) The length of the skywell has a certain effect on all indoor wind environments, and the variation in indoor wind speed is smallest when the length of the skywell is 7.5 m. When selecting the design size of the skywell, the length of the skywell can be increased accordingly. (2) The width of the skywell for the indoor wind environment is divided into two cases, when the length of the skywell is less than 3.75 m, increasing the width of the skywell will make the indoor wind environment more unstable. However, when the length of the skywell is greater than 3.75 m, the width of the skywell is positively related to the comfort of the indoor wind environment. (3) The area of the skywell should not be too large, usually between 11.25 m² and 18.75 m². A slender skywell is more likely to provide a comfortable indoor wind environment. (4) After extensive evaluation, we found that the comfort of the indoor wind environment is high when the width of the skywell is 2 m. The optimum dimensions for the ventilation performance of the skywell are 7.5 m in length and 2 m in width. Full article

The use of methane as a carbon source for producing bacterial single-cell protein (SCP) has been one of the most interesting developments in recent years. Most of these upcoming industries are using a methanotroph, Methylococcus capsulatus Bath, for SCP production using natural gas as the substrate. In the present study, we have explored the possibility of using an indigenously isolated methanotroph from a rice field in India, Methylomagnum ishizawai strain KRF4, for producing SCP from biogas [derived from cow dung]. The process was eco-friendly, required minimal instruments and chemicals, and was carried out under semi-sterile conditions in a tabletop fish tank. As the name suggests, Methylomagnum is a genus of large methanotrophs, and the strain KRF4 had elliptical to rectangular size and dimensions of ~4–5 µm × 1–2 µm. In static cultures, when biogas and air were supplied in the upper part of the growing tank, the culture grew as a thick pellicle/biofilm that could be easily scooped. The grown culture was mostly pure, from the microscopic observations where the large size of the cells, with rectangular-shaped cells and dark granules, could easily help identify any smaller contaminants. Additionally, the large cell size could be advantageous for separating biomass during downstream processing. The amino acid composition of the lyophilized biomass was analyzed using HPLC, and it was seen that the amino acid composition was comparable to commercial fish meal, soymeal, Pruteen, and the methanotroph-derived SCP-UniProtein^®. The only difference was that a slightly lower percentage of lysine, tryptophan, and methionine was observed in Methylomagnum-derived SCP. Methylomagnum ishizawai could be looked at as an alternative for SCP derived from methane or biogas due to the comparable SCP produced, on the qualitative level. Further intensive research is needed to develop a continuous, sustainable, and economical process to maximize biomass production and downstream processing. Full article