Search Results (7,455)

Accurate information on waste composition is essential for strategic planning in waste management and developing environmental technologies. However, detailed analyses of individual waste containers are both time- and cost-intensive, resulting in a limited number of available samples. Therefore, it is crucial to apply statistical methods that enable reliable estimation of average waste composition and its variability, while accounting for territorial differences. This study presents a statistical approach based on territorial stratification, aggregating data from individual waste container analyses to higher geographic units. The methodology was applied in a case study conducted in the Czech Republic, where 19.4 tons of mixed municipal waste (MMW) were manually analyzed in selected representative municipalities. The method considers regional heterogeneity, monitors the precision of partial estimates, and supports reliable aggregation across stratified regions. Three alternative approaches for constructing interval estimates of individual waste components are presented. Each interval estimate addresses variability from the random selection of waste containers and the selection of strata representatives at multiple levels. The proposed statistical framework is particularly suited to situations where the number of samples is small, a common scenario in waste composition analysis. The approach provides a practical tool for generating statistically sound insights under limited data conditions. The main fractions of MMW identified in the Czech Republic were as follows: paper 6.7%, plastic 7.3%, glass 3.6%, bio-waste 28.4%, metal 2.1%, and textile 3.0%. The methodology is transferable to other regions with similar waste management systems. Full article

Since the early days of silicon manufacturing, hydrogen gas treatment has been used to control the defect concentrations. Its beneficial effect can be enhanced using hydrogen plasma as a source of active atomic hydrogen. Hydrogen plasma modification of c-Si surface can be challenging because the plasma can induce precursors of defect centers that can persist at the interface and/or grown oxide after subsequent thermal oxidation. In the present study, we investigate nanoscale silicon dioxides with thicknesses in the range of 6–22 nm grown at low temperature (850 °C) in dry oxygen on radio frequency (RF) hydrogen plasma-treated silicon surface. The properties of these oxides are compared to oxides grown following standard Radio Corporation of America (RCA) Si technology. Electroreflectance measurements reveal better interface quality with enhanced electron mobility and lowered oxidation-induced stress levels when the oxides are grown on H-plasma modified c-Si substrates. These results are in good accordance with the reduced defect concentration established from the analysis of the current–voltage (I-V) and multifrequency capacitance–voltage (C-V) characteristics of metal-oxide-semiconductor (MOS) capacitors incorporating the Si-SiO₂ structures. The study proves the potential of hydrogen plasma treatment of Si prior to oxidation for various Si-based applications. Full article

Metal halide perovskites have appeared as a promising semiconductor for high-efficiency and low-cost photovoltaic technologies. However, their performance and long-term stability are dramatically constrained by defects at the surface and grain boundaries of polycrystalline perovskite films formed during the processing. Herein, we propose a defect-targeted passivation strategy using 2-chlorocinnamic acid (2-Cl) to simultaneously enhance the efficiency and stability of perovskite solar cells (PSCs). The crystallization kinetics, film morphology, and optical and electronic properties of the used formamidinium–cesium lead halide (FA_0.85Cs_0.15Pb(I_0.95Br_0.05)₃, FACs) absorber were modulated and systematically investigated by various characterizations. Mechanistically, the carbonyl group in 2-Cl coordinates with undercoordinated Pb²⁺ ions, while the chlorine atom forms Pb–Cl bonds, effectively passivating the surface and interfacial defects. The optimized FACs perovskite film was incorporated into inverted (p-i-n) PSCs with a typical architecture of ITO/NiO_x/PTAA/Al₂O₃/FACs/PEAI/PCBM/BCP/Ag. The optimal device delivers a champion power conversion efficiency (PCE) of 22.58% with an open-circuit voltage of 1.14 V and a fill factor of 82.8%. Furthermore, the unencapsulated devices retain 90% of their initial efficiency after storage in ambient air for 30 days and 83% of their original PCE after stress under 1 sun illumination with maximum power point tracking at 50 °C in a N₂ environment, demonstrating the practical potential of dual-site molecular passivation for durable perovskite photovoltaics. Full article

Corrosion has a significant impact on the economic and environmental sustainability of metal-based infrastructure and products. This position paper explores the intrinsic relationship between corrosion protection and sustainability, examining the economic costs, environmental impacts and technological strategies involved. While corrosion results in resource waste, energy loss, and increased CO₂ emissions, effective corrosion management can extend the service life of metallic components, thus preserving resources and minimizing environmental burden. The approaches such as Total Cost of Ownership (TCO) and Life Cycle Analysis (LCA) can provide a framework for selecting the most cost-efficient and environmentally friendly corrosion protection method in view of the required lifetime. The paper emphasises the crucial role of material selection, design optimization, recyclability and environmentally friendly coatings. Regulatory pressures and new trends such as machine learning are also discussed. Achieving sustainability goals requires greater awareness, education, interdisciplinary collaboration, and continued innovation in corrosion protection strategies. Full article

Total ankle arthroplasty (TAA) has evolved significantly through advances in alloy selection and manufacturing technologies. This narrative review examines the metallurgical foundations of contemporary TAA implants, analyzing primary alloy systems and their mechanical properties. Cobalt-chromium alloys provide superior mechanical strength and durability but present metal ion release concerns, while titanium alloys (Ti6Al4V) optimize biocompatibility with elastic modulus values (101–113 GPa) closer to bone, despite tribological limitations. Novel β-titanium formulations (Ti-35Nb-7Zr-5Ta, Ti10Mo6Zr4Sn3Nb) eliminate toxic aluminum and vanadium components while achieving lower elastic modulus values (50–85 GPa) that better match cortical bone properties. Manufacturing has transitioned from traditional methods (investment casting, forging, CNC machining) toward additive manufacturing technologies. Selective laser melting and electron beam melting enable patient-specific geometries, controlled porosity, and optimized microstructures, though challenges remain with residual stresses, surface finish requirements, and post-processing needs. Emerging biodegradable materials, composite structures, and hybrid implant designs represent promising future directions for addressing current material limitations. This review provides evidence-based insights for alloy selection and manufacturing approaches, emphasizing the critical role of materials engineering in TAA implant performance and clinical outcomes. Full article

The transition to high-energy-density lithium metal batteries (LMBs) is essential for advancing electric vehicle (EV) technologies beyond the limitations of conventional lithium-ion batteries. A key challenge in scaling LMB production is the precise, contamination-free separation of lithium metal (LiM) anodes, hindered by lithium’s strong adhesion to mechanical cutting tools. This study investigates high-speed, contactless laser cutting as a scalable alternative for shaping double-coated LiM anodes. The effects of pulse duration, pulse energy, repetition frequency, and scanning speed were systematically evaluated using a nanosecond pulsed laser system on 30 µm LiM foils laminated on both sides of an 8 µm copper current collector. A maximum single-pass cutting speed of 3.0 m/s was achieved at a line energy of 0.06667 J/mm, with successful kerf formation requiring both a minimum pulse energy (>0.4 mJ) and peak power (>2.4 kW). Cut edge analysis showed that shorter pulse durations (72 ns) significantly reduced kerf width, the heat-affected zone (HAZ), and bulge height, indicating a shift to vapor-dominated ablation, though with increased spatter due to recoil pressure. Optimal edge quality was achieved with moderate pulse durations (261–508 ns), balancing energy delivery and thermal control. These findings define critical laser parameter thresholds and process windows for the high-speed, high-fidelity cutting of double-coated LiM battery anodes, supporting the industrial adoption of nanosecond laser systems in scalable LMB electrode manufacturing. Full article

We present a highly sensitive and selective gas sensor based on an advanced silicon-on-insulator tunnel field-effect transistor (SOI-TFET) architecture, enhanced through the integration of customized conducting polymers. In this design, traditional metal gates are replaced with distinct functional polymers—PPP-TOS/AcCN, PP-TOS/AcCN, PP-FE(CN)₆³⁻/H₂O, PPP-TCNQ-TOS/AcCN, and PPP-ClO₄/AcCN—which enable precise molecular recognition and discrimination of various target gases. To further enhance sensitivity, the device employs an oppositely doped source region, significantly improving gate control and promoting stronger band-to-band tunneling. This structural modification amplifies sensing signals and improves noise immunity, allowing reliable detection at trace concentrations. Additionally, optimization of the subthreshold swing contributes to faster switching and response times. Thermal stability is addressed by embedding a P-type buffer layer within the buried oxide, which increases thermal conductivity and reduces lattice temperature, further stabilizing device performance. Experimental results demonstrate that the proposed sensor outperforms conventional SOI-TFET designs, exhibiting superior sensitivity and selectivity toward analytes such as methanol, chloroform, isopropanol, and hexane. Beyond gas sensing, the unique polymer-functionalized gate design enables integration of microbial biosensing capabilities, making the platform highly versatile for biochemical detection. This work offers a promising pathway toward ultra-sensitive, low-power sensing technologies for environmental monitoring, industrial safety, and medical diagnostics. Full article

The aim of this study is a detailed methodological analysis of the bending technology based on literature sources and the analysis of the correlation between the technological parameters. During this research the process of the determination of the technological parameters and their practical interpretation is given special attention. We analyze the technological process in a clear and understandable way using our own prepared figures to assist industrial and educational usage. This work contributes to a deeper understanding of bending technology and supports the basis of the technological decision. Furthermore four experiments will be conducted to find a correlation between the actual variable technological parameter (more variables will be selected) and the received technological parameters to analyze the function between these influential factors. This study can help industrial engineers and university students to understand the complexity of this technology, design all of the technological parameters that are needed to execute this technology for the manufacturing process, and enhance the quality of this metal forming process. Full article

Laser powder bed fusion (L-PBF) is a unique technology that enables manufacturing geometrically complex metal alloys, including Ti-6Al-4V parts. The microstructure of Ti-6Al-4V is determined by its localized thermal history, which is affected by not only the L-PBF process but also the geometry of the part. Understanding the microstructure at specific locations in complex geometries is of great importance in predicting the mechanical performance of Ti-6Al-4V parts. This work investigates the effects of geometric features on the local microstructure. Three geometries, namely, holes, overhangs, and penholders, were designed and used for this study. Three different laser powers, namely 150 W, 250 W, and 350 W, were set to print those geometries. The use of a lower laser power results in improved print quality. While the martensite phase dominates the bulk of the L-PBF Ti-6Al-4V parts, a fine α+β lamellar structure can form at down-skin regions of printed horizontal holes and overhangs. Moreover, the direction of the columnar prime β grain can shift due to directional heat dissipation. The local microstructural evolution after heat treatment is investigated as well. Full article

As a novel energy storage technology, seawater batteries exhibit significant application potential across various domains, including marine exploration, underwater communication, and island power supply. However, the deep-sea low-temperature environment adversely affects the performance of seawater battery systems. This paper proposes a seawater metal–air battery system equipped with a preheater (SMAB-P). This innovative system establishes stable natural circulation and utilizes the high-temperature seawater within the system to preheat the incoming low-temperature seawater, thereby effectively enhancing battery performance. It was found that, compared with the SMAB system without a preheater, when achieving a heat recovery rate of 100% the average temperature of seawater in the electrode plate area of the SMAB-P system can be increased by 54%. Consequently, the electrical conductivity of seawater within the system can be increased by approximately 20%, leading to a significant reduction in ohmic losses and an enhancement in the load voltage of the battery. Furthermore, increasing either the height or width of the electrode plate can enhance self-driven force and circulation flow rate, as well as both average and maximum temperatures of seawater in the electrode plate area to some extent. Reducing the annular space of the preheater can significantly increase the seawater temperature within the system, but excessive reduction may hinder the effective replacement of fresh seawater in the system. It is also noted that seawater velocity in the electrode plate channels remains relatively low and evenly distributed while exhibiting very small temperature variation. Full article

Sulfate radical-based advanced oxidation processes (AOPs) are effective for removing organic pollutants from wastewater. In this study, transition metal-doped cobalt oxyhydroxide (CoOOH) was synthesized as an efficient peroxymonosulfate (PMS) activator for the decolorization of rhodamine B. Doping CoOOH with transition metals enhanced its PMS activation performance compared with that of pure CoOOH. Notably, the reaction rate constant in the Ni-CoOOH/PMS system was approximately 4.3 times higher than that in the CoOOH/PMS system. The presence of multiple metals in the catalyst facilitated efficient Co²⁺/Co³⁺ redox cycling, resulting in improved PMS activation and more effective organic pollutant removal. This study highlights the potential of CoOOH-based materials for use in environmental remediation technologies utilizing PMS. Full article

The global scarcity of freshwater, driven by population growth and the unequal distribution of water resources, has intensified the need for alternative water supply technologies. Among the most promising solutions, adsorption-based atmospheric water harvesting (AWH) systems offer the ability to extract water vapor directly from ambient air, even under low-humidity conditions. This review presents a comprehensive overview of the thermodynamic principles and material characteristics governing these systems, with particular emphasis on adsorption isotherms and their role in predicting and optimizing system performance. A generalized theoretical framework is proposed to assess the energy efficiency of thermally driven AWH devices, based on key material parameters. Recent developments in sorbent materials, especially metal–organic frameworks (MOFs) and advanced zeolites, are examined for their high-water uptake, regeneration efficiency, and potential for operation under real climatic conditions. The Dubinin–Astakhov and modified Langmuir isotherm models are reviewed for their effectiveness in describing nonlinear sorption behaviors critical to performance modeling. In addition, component-level design strategies for adsorption-based AWH systems are discussed. The integration of solar energy is also discussed, highlighting recent prototypes and design strategies that have achieved water yields ranging from 0.1 to 2.5 L m⁻²/day and specific productivities up to 2.8 L kg⁻¹ using MOF-801 at 20% RH. Despite notable progress, challenges remain, including limited productivity in non-optimized setups, thermal losses, long-term material stability, and scalability. This review concludes by identifying future directions for material development, system integration, and modeling approaches to advance the practical deployment of efficient and scalable AWH technologies. Full article

With the continuous exploration and advancement of communication frequency bands, terahertz and mid-to-far-infrared communication systems have attracted significant attention in recent years. Modulators are essential components in these systems, making the enhancement of modulator performance in the infrared and terahertz bands a prominent research focus. In this study, we propose a high-performance infrared transmission-type modulator based on the plasmon resonance effect of graphene nanoribbons. This design synergistically exploits near-field enhancement from metal slits and defect states in one-dimensional photonic crystals to strengthen light–graphene interactions. The modulator achieves a modulation depth exceeding 80% and an operating bandwidth greater than 4 THz in the mid-infrared range, enabling efficient signal modulation for free-space optical communication. Importantly, the proposed design alleviates experimental challenges typically associated with the need for high graphene mobility and a wide Fermi energy tuning range in conventional approaches, thereby improving its practical feasibility. Moreover, the approach is scalable to far-infrared and terahertz bands, offering valuable insights for advancing signal modulation technologies across these spectral regions. Full article

This review aims to advance quartz processing technology by examining the surface properties, flotation behavior, and selective flotation mechanisms of quartz mineral. Characterized by a strong negative charge over a wide pH range and an isoelectric point around pH 2, quartz surfaces allow physical adsorption of cationic collectors, particularly amines, which render the quartz surface hydrophobic and enhance bubble–particle interactions. In contrast, flotation with anionic collectors requires prior surface activation via multivalent metal cations such as Ca²⁺. The pH value of the medium plays a critical role in both collector adsorption and flotation selectivity. Both direct and reverse flotation strategies can be used, depending on whether quartz is targeted as a valuable mineral or a gangue mineral. In direct flotation, depressants like carboxymethyl cellulose and starch are used to depress gangue minerals, while in reverse flotation, quartz is depressed using chemicals such as fluoride ions and cationic polymers. To improve the efficiency and selectivity of quartz flotation, further research is needed on surface chemistry, collector adsorption mechanisms, and the transition from laboratory-scale experiments to industrial applications. Full article

As emerging pollutants, antibiotic resistance genes (ARGs) have been recognized as originating from diverse sources. Among these, the use of livestock feed and veterinary drugs was identified as the primary source of ARGs in livestock manure. ARGs were found to be widely distributed in global environments, particularly in agriculture-related soils, water bodies, and the atmosphere, posing potential threats to ecological environments and human health. This paper reviewed the degradation mechanisms of ARGs during aerobic composting of livestock manure and the safety evaluation of compost products. Aerobic composting was demonstrated to be an effective method for degrading ARGs, primarily through mechanisms such as high-temperature elimination of ARG-carrying microorganisms, reduction in host bacterial abundance, and inhibition of horizontal gene transfer. Factors including the physicochemical properties of the composting substrate, the use of additives, and the presence of antibiotic and heavy metal residues were shown to influence the degradation efficiency of ARGs, with compost temperature being the core factor. The safety of organic fertilizers encompassed multiple aspects, including heavy metal content, seed germination index, and risk assessments based on ARG residues. The analysis indicated that deficiencies existed in areas such as the persistence of thermotolerant bacteria carrying ARGs, the dissemination of extracellular antibiotic resistance genes (eARGs), and virus-mediated gene transfer. Future research should focus on (1) the removal of thermotolerant bacteria harboring ARGs; (2) the decomposition of eARGs or the blocking of their transmission pathways; (3) the optimization of ultra-high temperature composting parameters; and (4) the analysis of interactions between viruses and resistant hosts. This study reviews the mechanisms, influencing factors, and safety assessment of aerobic composting for degrading ARGs in livestock manure. It not only deepens the understanding of this important environmental biotechnology process but also provides a crucial knowledge base and practical guidance for effectively controlling ARG pollution, ensuring agricultural environmental safety, and protecting public health. Additionally, it clearly outlines the key paths for future technological optimization, thus holding significant implications for the environment, agriculture, and public health. Full article