Search Results (986)

This study investigates the use of waste glass powder derived from fluorescent lamps as a partial replacement for cement in mortar production, aiming to valorize this Waste from Electrical and Electronic Equipment (WEEE) and enhance sustainability in the construction sector. Mortars were formulated by substituting 25% of cement by volume with glass powders from fluorescent lamp glass and green bottle glass. The experimental program evaluated mechanical strength, durability parameters and ecotoxicological performance. Results revealed that clean fluorescent lamp mortars showed the most promising mechanical behavior, exceeding the reference in long-term compressive (54.8 MPa) and flexural strength (10.0 MPa). All glass mortars exhibited significantly reduced chloride diffusion coefficients (85–89%) and increased electrical resistivity (almost 4 times higher), indicating improved durability. Leaching tests confirmed that the incorporation of fluorescent lamp waste did not lead to hazardous levels of heavy metals in the cured mortars, suggesting effective encapsulation. By addressing both technical (mechanical and durability) and ecotoxic performance, this research contributes in an original and relevant way to the development of more sustainable building materials. Full article

Plastics make up a significant proportion of the stream of the European Waste of Electric and Electronic Equipment (WEEE), yet the use of recycled plastic materials is very low in new manufactured products. A description of the WEEE waste stream in Europe is given, with a focus on the plastic materials commonly found in WEEE that include four principal polymers: polypropylene (PP), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS). Furthermore, the legislative aspects related to WEEE and plastics recycling in Europe are complex, and numerous norms have been dictated by the European Commission. These norms are crucial to the sector of polymer recycling and production in Europe. Moreover, an overview of the entire treatment chain is presented. More specifically, each step of a typical recycling chain is introduced, with a focus on the sorting of plastics and the separation of polymers. Lastly, the influence of contaminants in the plastic fraction is discussed, both in terms of polymer particles and unwanted additives. By showing the impact of the purity rate on the mechanical properties of recycled plastics, the consequences of inadequate end-of-life treatment for WEEE-plastics is highlighted, hence linking the quality of recycled plastics to the separation step and the re-compounding of recycled granulates. Full article

During the last few years, the requirements for highly efficient, sustainable, and versatile materials in modern biomedicine, aircraft and aerospace industries, automotive production, and electronic and electrical engineering applications have increased. This has led to the development of new and innovative methods for material modification and optimization. This can be achieved in many different ways, but one such approach is the application of surface thin films. They can be conductive (metallic), semi-conductive (metal-ceramic), or isolating (polymeric). Special emphasis is placed on applying semi-conductive thin films due to their unique properties, be it electrical, chemical, mechanical, or other. The particular thin films of interest are composite ones of the type of transition metal oxide (TMO) and transition metal nitride (TMN), due to their widespread configurations and applications. Regardless of the countless number of studies regarding the application of such films in the aforementioned industrial fields, some further possible investigations are necessary to find optimal solutions for modern problems in this topic. One such problem is the possibility of characterization of the applied thin films, not via textbook approaches, but through a simple, modern solution using their electrical properties. This can be achieved on the basis of measuring the films’ electrical impedance, since all different semi-conductive materials have different impedance values. However, this is a huge practical work that necessitates the collection of a large pool of data and needs to be based on well-established methods for both characterization and formation of the films. A thorough review on the topic of applying thin films using physical vapor deposition techniques (PVD) in the field of different modern applications, and the current results of such investigations are presented. Furthermore, current research regarding the possible methods for applying such films, and the specifics behind them, need to be summarized. Due to this, in the present work, the specifics of applying thin films using PVD methods and their expected structure and properties were evaluated. Special emphasis was paid to the electrical impedance spectroscopy (EIS) method, which is typically used for the investigation and characterization of electrical systems. This method has increased in popularity over the last few years, and its applicability in the characterization of electrical systems that include thin films formed using PVD methods was proven many times over. However, a still lingering question is the applicability of this method for backwards engineering of thin films. Currently, the EIS method is used in combination with traditional techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), and others. There is, however, a potential to predict the structure and properties of thin films using purely a combination of EIS measurements and complex theoretical models. The current progress in the development of the EIS measurement method was described in the present work, and the trend is such that new theoretical models and new practical testing knowledge was obtained that help implement the method in the field of thin films characterization. Regardless of this progress, much more future work was found to be necessary, in particular, practical measurements (real data) of a large variety of films, in order to build the composition–structure–properties relationship. Full article

This study investigates the effects of incorporating recycled concrete powder (RCP) as a supplementary cementitious material in Portland cement composites at replacement levels of 5–30% by weight. A comprehensive characterization using isothermal calorimetry, electrical conductivity measurements, thermogravimetric analysis, FT-IR spectroscopy, and scanning electron microscopy revealed that RCP modified the hydration behavior and microstructural development. The results showed a linear 16.5% reduction in the total heat of hydration (from 145.38 to 121.44 J/g) at 30% RCP content, accompanied by a 26.5% decrease in peak electrical conductivity (19.16 to 14.08 mS/cm) and delayed reaction kinetics. Thermal analysis demonstrated an increased stability of hydration products, with portlandite decomposition temperatures rising by up to 10.8 °C. Microstructural observations confirmed the formation of denser but more amorphous C–S–H phases alongside increased interfacial porosity at higher RCP contents. The study provides quantitative evidence of RCP’s dual functionality as both an inert filler and a nucleation agent, identifying an optimal 20–25% replacement range that balances performance and sustainability. These findings advance the understanding of construction waste utilization in cementitious materials and provide practical solutions for developing more sustainable building composites while addressing circular economy objectives in the construction sector. Full article

The electrodynamics of current provide much of our technology, from telegraphs to the wired infrastructure powering the circuits of our electronic technology. Current flow is analyzed by its own rules that involve the Maxwell Ampere law and magnetism. Electrostatics does not involve magnetism, and so current flow and electrodynamics cannot be derived from electrostatics. Practical considerations also prevent current flow from being analyzed one charge at a time. There are too many charges, and far too many interactions to allow computation. Current flow is essential in biology. Currents are carried by electrons in mitochondria in an electron transport chain. Currents are carried by ions in nerve and muscle cells. Currents everywhere follow the rules of current flow: Kirchhoff’s current law and its generalizations. The importance of electron and proton flows in generating ATP was discovered long ago but they were not analyzed as electrical currents. The flow of protons and transport of electrons form circuits that must be analyzed by Kirchhoff’s law. A chemiosmotic theory that ignores the laws of current flow is incorrect physics. Circuit analysis is easily applied to short systems like mitochondria that have just one internal electrical potential in the form of the Hodgkin Huxley Katz (HHK) equation. The HHK equation combined with classical descriptions of chemical reactions forms a computable model of cytochrome c oxidase, part of the electron transport chain. The proton motive force is included as just one of the components of the total electrochemical potential. Circuit analysis includes its role just as it includes the role of any other ionic current. Current laws are now needed to analyze the flow of electrons and protons, as they generate ATP in mitochondria and chloroplasts. Chemiosmotic theory must be replaced by an electro-osmotic theory of ATP production that conforms to the Maxwell Ampere equation of electrodynamics while including proton movement and the proton motive force. Full article

The urgent demand for sustainable energy solutions in the face of climate change and resource depletion has catalyzed a global shift toward cleaner energy production and more efficient storage technologies. Lithium-ion batteries (LIBs), as the cornerstone of modern portable electronics, electric vehicles, and grid-scale storage systems, are continually evolving to meet the growing performance requirements. In this dynamic context, two-dimensional (2D) materials have emerged as highly promising candidates for use in electrodes due to their layered structure, tunable electronic properties, and high theoretical capacity. Among 2D materials, molybdenum disulfide (MoS₂) has gained increasing attention as a promising low-dimensional candidate for LIB anode applications. This review provides a comprehensive yet concise overview of recent advances in the application of MoS₂ in LIB electrodes, with particular attention to its unique electrochemical behavior at the nanoscale. We critically examine the interplay between structural features, charge-storage mechanisms, and performance metrics—chiefly the specific capacity, rate capability, and cycling stability. Furthermore, we discuss current challenges, primarily poor intrinsic conductivity and volume fluctuations, and highlight innovative strategies aimed at overcoming these limitations, such as through nanostructuring, composite formation, and surface engineering. By shedding light on the opportunities and hurdles in this rapidly progressing field, this work offers a forward-looking perspective on the role of MoS₂ in the next generation of high-performance LIBs. Full article

The rapid increase in waste electrical and electronic equipment (WEEE) creates major environmental and governance issues in developing countries like Ecuador struggle because they with minimal formal collection and recycling rates. This research presents a potential sustainable management approach that tracks products through their life cycles while following circular economy principles that include product extension and material extraction and waste minimization. A systematic literature review (SLR) using the PRISMA methodology combined with a bibliometric analysis found essential global strategies and technological frameworks and regulatory frameworks. The analysis of articles demonstrates that information management systems (IMSs) together with digital technologies and consistent regulations serve as essential elements for enhancing traceability and material recovery and formal recycling processes. A WEEE management IMS model was developed for the Ecuadorian market through an analysis of the findings; it follows a five-stage development process, starting from the technological infrastructure setup to complete data visualization integration. The proposed model is designed to enable public–private–community partnerships using digital tools that promote sustainable practices. The combination of circular strategies with traceability technologies and strong regulatory frameworks leads to improved WEEE governance, which supports sustainable system transitions in emerging economies. Full article

This study focuses on developing a novel clinker-free cement, specifically comprising phosphorus slag-based cementitious materials (PSCMs), by utilizing lime and industrial byproducts, including granulated electric furnace phosphorus slag and fluidized bed combustion bottom ash. The optimal composition of PSCM was determined by investigating the effects of different proportions of activators (water glass and sodium sulfate) and retarder (potassium fluoride) on the setting time and the mechanical strength of PSCMs. Performance evaluations demonstrated that the compressive and flexural strengths of the optimal PSCM formulation at 28 days were 64.1 MPa and 7.5 MPa, respectively. Notably, concrete prepared with the optimal PSCM exhibited superior freeze–thaw resistance and sulfate resistance compared to Portland cement concrete of equivalent strength grades. The comprehensive characterization of selected PSCM compositions, conducted using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscope–energy-dispersive spectrometry (SEM-EDS), provided in-depth insights into the interrelationship among mechanical properties, durability, and microstructural characteristics. SEM-EDS analysis confirmed that calcium aluminosilicate hydrate and sodium aluminosilicate hydrate are the predominant hydration products of PSCMs. FTIR and TG analyses elucidated the continuous hydration behavior of PSCMs during the curing process, while SEM observations revealed a densely compact microstructure in the hardened PSCM paste. Full article

Background/Objectives: Although the nanocomposite of poly(L-lactic acid) with graphene oxide (PLLA-GO) shows promise for tissue engineering, its specific bioactive interactions with diverse cell lineages during early tissue regeneration remain unclear. This study comprehensively investigated the in vitro multifaceted biocompatibility of PLLA-GO using human fibroblasts (FN1 cells), murine mesenchymal stem cells (mBMSCs), and human umbilical vein endothelial cells (HUVECs). Methods: Morphological analyses were performed using optical and scanning electron microscopy, while proliferation dynamics were assessed via CFSE staining. Cell cycle progression was evaluated using flow cytometry, mitochondrial activity was examined through TMRE staining, and inflammatory cytokine profiling was performed via Cytometric Bead Array (CBA). Results: PLLA-GO exhibited primary biocompatibility across all evaluated cell lines, characterized by efficient adhesion and proliferation. However, significant cell-type-dependent modulations were observed. The FN1 cells exhibited proliferative adaptation but induced accelerated scaffold degradation, as evidenced by a substantial increase in cellular debris (5.93% control vs. 34.38% PLLA-GO; p = 0.03). mBMSCs showed a transient initial proliferative response and a significant 21.66% increase in TNF-α production (179.67 pg/mL vs. 147.68 pg/mL in control; p = 0.03). HUVECs demonstrated heightened mitochondrial sensitivity, exhibiting a 32.19% reduction in mitochondrial electrical potential (97.07% control vs. 65.82% PLLA-GO; p ≤ 0.05), alongside reductions in pro-inflammatory cytokines TNF-α (8.73%) and IL-6 (12.47%). Conclusions: The PLLA-GO processing method is crucial for its properties and subsequent cellular interactions. Therefore, rigorous and specific preclinical evaluations—considering both cellular contexts and fabrication—are indispensable to ensure the safety and therapeutic potential of PLLA-GO in tissue engineering and regenerative medicine. Full article

Fresh-cut potato slices are prone to browning. Although freezing is an effective method of preserving food, freezing and thawing cause inevitable damage to potato tissues. This study explored the freeze-protective effects of trehalose and sorbitol under atmospheric pressure impregnation and vacuum impregnation by analyzing their influences on the cell structural and textural characteristics of frozen–thawed potato slices. The results showed that both trehalose and sorbitol can significantly improve the quality of frozen–thawed potato slices. Vacuum impregnation resulted in a higher total sugar content in the impregnated potato slices than atmospheric pressure impregnation (p < 0.05). Sorbitol impregnation significantly reduced cell damage and nutrient loss of frozen–thawed potato slices; specifically, under vacuum impregnation conditions, the juice loss rate and relative electrical conductivity decreased to 7.58 ± 0.47% and 32.90 ± 1.83 mS/cm, respectively. Texture analysis showed that sorbitol impregnation resulted in significantly higher puncture hardness and TPA hardness in frozen–thawed potato slices than trehalose impregnation. Furthermore, observations of cell activity and transmission electron microscopy of potato tissues verified sorbitol’s advantages in maintaining cell structure integrity and reducing ice crystal damage. Hence, sorbitol vacuum impregnation is highly recommended as a pretreatment in potato quick freezing processes. This study provides a theoretical basis and technical support for the improvement of the quality of quick-frozen potato products, and for the later processing and manufacturing of frozen potato slices. Full article

A key step to optimize the tests of semiconductors during the production process is to improve the prediction of the final yield from the defects detected on the wafers during the production process. This study investigates the link between the defects detected by a Scanning Electron Microscope (SEM) and the electrical failure of the final semiconductors, with two main objectives: (a) to identify the best layers to inspect by SEM; (b) to develop a model that predicts electrical failures of the semiconductors from the detected defects. The first objective has been reached by a model based on Odds Ratio that gave a (ranked) list of the layers that best predict the final yield. This allows process engineers to concentrate inspections on a few important layers. For the second objective, a regression/classification model based on Gradient Boosting has been developed. As a by-product, this latter model confirmed the results obtained by Odds Ratio analysis. Both models take account of the high lacunarity of the data and have been validated on two distinct datasets from STMicroelectronics. Full article

Under the accelerating global energy restructuring and the deepening carbon neutrality strategy, hydrogen energy has emerged with increasing strategic value as a zero-carbon secondary energy carrier. Water electrolysis technology based on renewable energy is regarded as an ideal pathway for large-scale green hydrogen production. However, polymer electrolyte membrane (PEM) conventional water electrolysis faces dual constraints in economic feasibility and scalability due to its high electrical energy consumption and reliance on noble metal catalysts. The mixed ionic-electronic conducting oxygen transport membrane (MIEC–OTM) reactor technology offers an innovative solution to this energy efficiency-cost paradox due to its thermo-electrochemical synergistic energy conversion mechanism and process integration. This not only overcomes the thermodynamic equilibrium limitations in traditional electrolysis but also reduces electrical energy demand by effectively coupling with medium- to high-temperature heat sources such as industrial waste heat and solar thermal energy. Therefore, this review, grounded in the physicochemical mechanisms of oxygen transport membrane reactors, systematically examines the influence of key factors, including membrane material design, catalytic interface optimization, and parameter synergy, on hydrogen production efficiency. Furthermore, it proposes a roadmap and breakthrough directions for industrial applications, focusing on enhancing intrinsic material stability, designing multi-field coupled reactors, and optimizing system energy efficiency. Full article

Globalization and the spread of technological innovations have made world markets and economies increasingly unified and conditioned by international trade, not only for sales markets but above all for the supply of raw materials necessary for the functioning of the production complex of each country. Alongside oil and gold, the main commodities traded include industrial metals, such as aluminum and copper, mineral products such as gas, electrical and electronic components, agricultural products, and precious metals. The conflict between Russia and Ukraine tested the unification of markets, given that these are countries with notable raw materials and are strongly dedicated to exports. This suggests that commodity prices were able to influence the stock markets, especially in the countries most closely linked to the two belligerents in terms of import-export. Given the importance of industrial metals in this period of energy transition, the aim of our study is to analyze whether Industrial Metals volatility affects G7 stock markets. To this end, the BEKK-GARCH model is used. The sample period spans from 3 January 2018 to 17 September 2024. The results show that lagged shocks and volatility significantly and positively influence the current conditional volatility of commodity and stock returns during all periods. In fact, past shocks inversely influence the current volatility of stock indices in periods when external events disrupt financial markets. The results show a non-linear and positive impact of commodity volatility on the implied volatility of the stock markets. The findings suggest that the war significantly affected stock prices and exacerbated volatility, so investors should diversify their portfolios to maximize returns and reduce risk differently in times of crisis, and a lack of diversification of raw materials is a risky factor for investors. Full article

Microbial Fuel Cell (MFC) is a novel bioelectrochemical system that catalyzes the oxidation of chemical energy in organic waste and converts it directly into electrical energy through the attachment and growth of electroactive microorganisms on the electrode surface. This technology realizes the synergistic effect of waste treatment and renewable energy production. A CF-NiO-PANI capacitor composite anode was prepared by loading polyaniline on a CF-NiO electrode to improve the capacitance of a CF electrode. The electrochemical characteristics of the composite anode were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the electrode materials were analyzed comprehensively by scanning electron microscopy (SEM), energy diffusion spectrometer (EDS), and Fourier transform infrared spectroscopy (FTIR). MFC system based on CF-NiO-PANI composite anode showed excellent energy conversion efficiency in potato starch wastewater treatment, and its maximum power density increased to 0.4 W/m³, which was 300% higher than that of the traditional CF anode. In the standard charge–discharge test (C1000/D1000), the charge storage capacity of the composite anode reached 2607.06 C/m², which was higher than that of the CF anode (348.77 C/m²). Microbial community analysis revealed that the CF-NiO-PANI anode surface formed a highly efficient electroactive biofilm dominated by electrogenic bacteria (accounting for 47.01%), confirming its excellent electron transfer ability. The development of this innovative capacitance-catalytic dual-function anode material provides a new technical path for the synergistic optimization of wastewater treatment and energy recovery in MFC systems. Full article

Titanium dioxide (TiO₂) is a wide-bandgap semiconductor material with broad application potential, known for its excellent photocatalytic performance, high chemical stability, low cost, and non-toxicity. These properties make it highly attractive for applications in photovoltaic energy, environmental remediation, and optoelectronic devices. For instance, TiO₂ is widely used as a photocatalyst for hydrogen production via water splitting and for degrading organic pollutants, thanks to its efficient photo-generated electron–hole separation. Additionally, TiO₂ exhibits remarkable performance in dye-sensitized solar cells and photodetectors, providing critical support for advancements in green energy and photoelectric conversion technologies. Boron-doped diamond (BDD) is renowned for its exceptional electrical conductivity, high hardness, wide electrochemical window, and outstanding chemical inertness. These unique characteristics enable its extensive use in fields such as electrochemical analysis, electrocatalysis, sensors, and biomedicine. For example, BDD electrodes exhibit high sensitivity and stability in detecting trace chemicals and pollutants, while also demonstrating excellent performance in electrocatalytic water splitting and industrial wastewater treatment. Its chemical stability and biocompatibility make it an ideal material for biosensors and implantable devices. Research indicates that the combination of TiO₂ nanostructures and BDD into heterostructures can exhibit unexpected optical and electrical performance and transport behavior, opening up new possibilities for photoluminescence and rectifier diode devices. However, applications based on this heterostructure still face challenges, particularly in terms of photodetector, photoelectric emitter, optical modulator, and optical fiber devices under high-temperature conditions. This article explores the potential and prospects of their combined heterostructures in the field of optoelectronic devices such as photodetector, light emitting diode (LED), memory, field effect transistor (FET) and sensing. TiO₂/BDD heterojunction can enhance photoresponsivity and extend the spectral detection range which enables stability in high-temperature and harsh environments due to BDD’s thermal conductivity. This article proposes future research directions and prospects to facilitate the development of TiO₂ nanostructured materials and BDD-based heterostructures, providing a foundation for enhancing photoresponsivity and extending the spectral detection range enables stability in high-temperature and high-frequency optoelectronic devices field. Further research and exploration of optoelectronic devices based on TiO₂-BDD heterostructures hold significant importance, offering new breakthroughs and innovations for the future development of optoelectronic technology. Full article