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Microstructure and properties of 6Yb2O3-2Y2O3-ZrO2 composite nanoceramic powders by microwave-assisted co-precipitation method
No full textAbstract
The stability and other physicochemical characteristics of zirconia ceramics can be further improved by including stabilizers. In this study, the effect of different microwave calcination temperatures on 6Yb2O3-2Y2O3-ZrO2 composite nanoceramic powders was investigated by using the microwave calcination-assisted co-precipitation method, in which Yb2O3 and Y2O3 were used as stabilizers to co-doped ZrO2. The samples at different microwave calcination temperatures were characterized by XRD, TG-DTG, Raman, SEM, and FT-IR, and the effects of the microwave sintering process on the microstructure and grain growth behavior of the composite nanoceramic powders were further analyzed. The solid solution structure was created by adding Yb3+ and Y3+ with ionic radii larger than Zr4+. This resulted in O-O coupling and an increase in the concentration of oxygen vacancies close to the substitutional ions, which caused Zr4+ to be replaced by Yb3+ and Y3+ and suppressed the tetragonal to monoclinic phase transformation. The experimental results show that the co-doping of ZrO2 with Yb2O3 and Y2O3 has good phase stability, and there is no appearance of a monoclinic phase after microwave calcination. The precursor sample transforms from an amorphous form to a large number of cubic phases and a small number of tetragonal phases. The powder is spherical with a uniform particle size distribution. A calcination temperature of 1000 °C produced the maximum tetragonal phase ZrO2 content of 41.3 %, and a stability rate of 97.4 % made the best stability of the sample. 6Yb2O3-2Y2O3-ZrO2 composite nanoceramic powders' activation energy for grain development was further determined to be 22.03 kJ/mol. This work offers a theoretical and practical foundation for synthesizing zirconia ceramic powders with exceptional qualities.Abstract
The stability and other physicochemical characteristics of zirconia ceramics can be further improved by including stabilizers. In this study, the effect of different microwave calcination temperatures on 6Yb2O3-2Y2O3-ZrO2 composite nanoceramic powders was investigated by using the microwave calcination-assisted co-precipitation method, in which Yb2O3 and Y2O3 were used as stabilizers to co-doped ZrO2. The samples at different microwave calcination temperatures were characterized by XRD, TG-DTG, Raman, SEM, and FT-IR, and the effects of the microwave sintering process on the microstructure and grain growth behavior of the composite nanoceramic powders were further analyzed. The solid solution structure was created by adding Yb3+ and Y3+ with ionic radii larger than Zr4+. This resulted in O-O coupling and an increase in the concentration of oxygen vacancies close to the substitutional ions, which caused Zr4+ to be replaced by Yb3+ and Y3+ and suppressed the tetragonal to monoclinic phase transformation. The experimental results show that the co-doping of ZrO2 with Yb2O3 and Y2O3 has good phase stability, and there is no appearance of a monoclinic phase after microwave calcination. The precursor sample transforms from an amorphous form to a large number of cubic phases and a small number of tetragonal phases. The powder is spherical with a uniform particle size distribution. A calcination temperature of 1000 °C produced the maximum tetragonal phase ZrO2 content of 41.3 %, and a stability rate of 97.4 % made the best stability of the sample. 6Yb2O3-2Y2O3-ZrO2 composite nanoceramic powders' activation energy for grain development was further determined to be 22.03 kJ/mol. This work offers a theoretical and practical foundation for synthesizing zirconia ceramic powders with exceptional qualities
Exploring ultrathin tungsten disulfide as a diffusion barrier for copper interconnects: advanced packaging reliability and a first-principles study
No full textAbstract
The robust diffusion barriers (DB) are crucial due to the significant prevention of copper (Cu) diffusion/migration, which negatively affects interconnect reliability and compatibility in advanced packaging. With a half-pitch size (20 nm and below) a conventional Ta/TaN DB has a thickness limit to shrinkage below 4 nm, addressing the limited Cu conductivity, and inferior barrier properties to block Cu diffusion. Therefore, ultrathin 0.7 nm tungsten disulfide (WS2) is utilized as a pioneering DB for Cu interconnects to address this issue. Herein, W is primarily sputtered and sulfurized at 400 °C to convert into WS2, later confirmed by several characterizations. Based on JE, CV, temperature-dependent breakdown, and DFT verification, we conclude that the ultrathin 0.7 nm WS2 effectively blocks the Cu diffusion in the range of 9.7–10 MV/cm. Notably, the research is strongly supported by reliability tests, including (−200 to 400 °C) temperature-dependent JE at both low (14.8 MV/cm) and high (8 MV/cm) temperatures, Cu electroplating, warpage tests, tape tests, and other relevant evaluations, which are currently of significant interest in packaging. The obtained results show that the WS2 DB serving both liner/barrier properties is excellent as compared to conventional Ta(liner)/TaN(barrier). The study demonstrates that WS2 is BEOL-compatible and industry-friendly, facilitating interconnect scaling beyond the current technology node, and we should not be surprised if used in future advanced packaging.Abstract
The robust diffusion barriers (DB) are crucial due to the significant prevention of copper (Cu) diffusion/migration, which negatively affects interconnect reliability and compatibility in advanced packaging. With a half-pitch size (20 nm and below) a conventional Ta/TaN DB has a thickness limit to shrinkage below 4 nm, addressing the limited Cu conductivity, and inferior barrier properties to block Cu diffusion. Therefore, ultrathin 0.7 nm tungsten disulfide (WS2) is utilized as a pioneering DB for Cu interconnects to address this issue. Herein, W is primarily sputtered and sulfurized at 400 °C to convert into WS2, later confirmed by several characterizations. Based on JE, CV, temperature-dependent breakdown, and DFT verification, we conclude that the ultrathin 0.7 nm WS2 effectively blocks the Cu diffusion in the range of 9.7–10 MV/cm. Notably, the research is strongly supported by reliability tests, including (−200 to 400 °C) temperature-dependent JE at both low (14.8 MV/cm) and high (8 MV/cm) temperatures, Cu electroplating, warpage tests, tape tests, and other relevant evaluations, which are currently of significant interest in packaging. The obtained results show that the WS2 DB serving both liner/barrier properties is excellent as compared to conventional Ta(liner)/TaN(barrier). The study demonstrates that WS2 is BEOL-compatible and industry-friendly, facilitating interconnect scaling beyond the current technology node, and we should not be surprised if used in future advanced packaging
Economically sustainable electrochemical–chemical purification strategy for deep removal and high-valued recovery of lead from Zn-NH4Cl-H2O system
No full textAbstract
Ammonia-based zinc smelting for secondary resources inevitably introduces lead impurities into the Zn-NH4Cl-H2O system, reducing cathode zinc purity and hindering electrodeposition performance. Conventional zinc powder cementation suffers from severe lead coating, low zinc utilization, and poor dosage control. To overcome these drawbacks, a novel electrochemical–chemical purification process was developed by exploiting the 0.555 V potential difference between Pb and Zn. Controlled electroreduction enables selective removal of Pb(II) and simultaneous recovery of metallic Pb with purity above 95 %. At 3–4 g/L Pb2+ and 50 A·m−2, ECP achieved 99.87 % lead removal, < 3 % zinc loss, and an energy consumption of 0.466 kWh·kg−1, significantly outperforming ZPP and zinc–graphite powder purification. Economic evaluation revealed net profits per tonne of zinc of 50.5 for ZPP and -356 for ECP, compared with -26.5 for ZGP. The ECP process thus provides an energy-efficient, economically viable, and environmentally sustainable route for deep purification of zinc leachate and resource recovery in ammonium chloride-based zinc metallurgy
Single-molecule resolution of oligopeptides in anti-aging cosmetics combined with nanopore readouts and deep learning model
No full textAbstract
Oligopeptides in anti-aging cosmetics stand out as active ingredients to interact with skin cell and accelerate the collagen synthesis and fibroblast proliferation. Some of them act as neurotransmitter- or enzyme inhibitor, while others are signal or carrier peptides. The ensemble techniques for the extraction and analysis of the bioactive peptides in cosmetic production involve ultrafiltration, enzymatic hydrolysis, fermentation, and high-performance liquid chromatography. This work provides a single-molecule approach for the resolution of various typical oligopeptides in anti-aging cosmetics. A nanopore with an aperture diameter of ∼2 nm is efficient for the shortest tripeptide to achieve good signal to noise ratio and translocation frequency. Oligoeptides with three to eight amino acids could be discriminated with a ∼ 2 nm single SiNx nanopore, this is also proved by AI modeling with an accuracy of ∼90%, except the argireline and hexapeptide-9 that hold similar translocation behavior in KCl. The assay for the argireline in three commercial anti-aging cosmetics reveals that the product from Viribati is purer than the other two and harbors the majority of argireline according to the comparison setups in a single nanopore device. Our work provides a significant insight in the qualification and quality control in anti-aging cosmetic market.Abstract
Oligopeptides in anti-aging cosmetics stand out as active ingredients to interact with skin cell and accelerate the collagen synthesis and fibroblast proliferation. Some of them act as neurotransmitter- or enzyme inhibitor, while others are signal or carrier peptides. The ensemble techniques for the extraction and analysis of the bioactive peptides in cosmetic production involve ultrafiltration, enzymatic hydrolysis, fermentation, and high-performance liquid chromatography. This work provides a single-molecule approach for the resolution of various typical oligopeptides in anti-aging cosmetics. A nanopore with an aperture diameter of ∼2 nm is efficient for the shortest tripeptide to achieve good signal to noise ratio and translocation frequency. Oligoeptides with three to eight amino acids could be discriminated with a ∼ 2 nm single SiNx nanopore, this is also proved by AI modeling with an accuracy of ∼90%, except the argireline and hexapeptide-9 that hold similar translocation behavior in KCl. The assay for the argireline in three commercial anti-aging cosmetics reveals that the product from Viribati is purer than the other two and harbors the majority of argireline according to the comparison setups in a single nanopore device. Our work provides a significant insight in the qualification and quality control in anti-aging cosmetic market
Multispecies As A Concept And Method
No full textAbstract
Drawing from the idea of concepts as methods, this chapter focuses on the multispecies concept. After an account on what concepts are and can do, the emergence, ideas and potentials of the multispecies concept are presented, followed by sections on multispecies studies and interpretation. Examples from the authors’ research projects and practices are given to illustrate multispecies concept as a method and a research position and what interpretation can then become. The authors suggests that as the concept of multispecies directs attention to situated complexities, then new ways of thinking are crafted in action, rather than prescribed as interpretations of a given world existing outside of engagement with it. Some of the consequences and (im)possibilities of this approach are then discussed.Abstract
Drawing from the idea of concepts as methods, this chapter focuses on the multispecies concept. After an account on what concepts are and can do, the emergence, ideas and potentials of the multispecies concept are presented, followed by sections on multispecies studies and interpretation. Examples from the authors’ research projects and practices are given to illustrate multispecies concept as a method and a research position and what interpretation can then become. The authors suggests that as the concept of multispecies directs attention to situated complexities, then new ways of thinking are crafted in action, rather than prescribed as interpretations of a given world existing outside of engagement with it. Some of the consequences and (im)possibilities of this approach are then discussed
Thermoresponsive Reconfigurable Intelligent Electromagnetic Surfaces Enabled by VO2 and Wood-Derived Nanocellulose, Suberin, and Biocarbon
No full textAbstract
Reconfigurable intelligent surfaces (RISs) are key enabling technologies for next-generation wireless telecommunication systems, offering dynamic control over electromagnetic (EM) wave propagation. However, most existing RIS demonstrations rely on conventional electronic or metallic platforms, raising concerns about resource availability, recyclability, and environmental sustainability. In this study, hybrid nanostructured RIS prototypes (Prototypes I–III) were designed and fabricated using sustainable, wood-derived materials, namely, cellulose nanofibers (CNFs), suberin, and biocarbon, in combination with thermoresponsive vanadium dioxide (VO2) nanoparticles. The EM performance of these RIS architectures was first optimized through full-wave simulations and then validated experimentally by the cast-layer deposition of VO2/CNF–suberin functional layers onto printed circuit board (PCB) substrates. Among the tested designs, Prototype I, comprising a functional layer of 95 wt % VO2, 2.5 wt % nonderivatized CNF, and 2.5 wt % suberin, exhibited the most pronounced thermal response, showing resonance frequency shifts of up to 19 MHz at a 5 GHz center frequency and phase shifts of 83° with temperature variation. Prototype II, containing cationic CNFs, demonstrated improved mechanical stability but reduced electrical continuity due to microstructural cracking, whereas Prototype III, modified with biocarbon, displayed diminished conductivity arising from its lower VO2 content. Degree of linear polarization (DOLP) analysis revealed early stage phase transitions that occurred prior to complete conductive pathway formation. Overall, the hybrid RIS architectures developed from VO2 and wood-derived materials through a sustainable processing route exhibited highly tunable, temperature-triggered EM modulation, with sensitivity ranging from low to high, depending on the material composition and assembly configuration.Abstract
Reconfigurable intelligent surfaces (RISs) are key enabling technologies for next-generation wireless telecommunication systems, offering dynamic control over electromagnetic (EM) wave propagation. However, most existing RIS demonstrations rely on conventional electronic or metallic platforms, raising concerns about resource availability, recyclability, and environmental sustainability. In this study, hybrid nanostructured RIS prototypes (Prototypes I–III) were designed and fabricated using sustainable, wood-derived materials, namely, cellulose nanofibers (CNFs), suberin, and biocarbon, in combination with thermoresponsive vanadium dioxide (VO2) nanoparticles. The EM performance of these RIS architectures was first optimized through full-wave simulations and then validated experimentally by the cast-layer deposition of VO2/CNF–suberin functional layers onto printed circuit board (PCB) substrates. Among the tested designs, Prototype I, comprising a functional layer of 95 wt % VO2, 2.5 wt % nonderivatized CNF, and 2.5 wt % suberin, exhibited the most pronounced thermal response, showing resonance frequency shifts of up to 19 MHz at a 5 GHz center frequency and phase shifts of 83° with temperature variation. Prototype II, containing cationic CNFs, demonstrated improved mechanical stability but reduced electrical continuity due to microstructural cracking, whereas Prototype III, modified with biocarbon, displayed diminished conductivity arising from its lower VO2 content. Degree of linear polarization (DOLP) analysis revealed early stage phase transitions that occurred prior to complete conductive pathway formation. Overall, the hybrid RIS architectures developed from VO2 and wood-derived materials through a sustainable processing route exhibited highly tunable, temperature-triggered EM modulation, with sensitivity ranging from low to high, depending on the material composition and assembly configuration
Thin-layer model for kinetic study and energy efficiency of crude zinc oxide under microwave drying
No full textAbstract
Crude zinc oxide, as a by-product of zinc smelting operations, is a recoverable secondary zinc resource that necessitates moisture removal through drying processes prior to its industrial-scale recycling applications. In this study, the crude zinc oxide is treated using microwave drying technology, and its drying kinetic characteristics are thoroughly investigated. By systematically regulating the parameters of initial mass, microwave power, and initial water content, the effects on drying rate, effective diffusion coefficient, and energy efficiency are comprehensively analyzed. The experimental results demonstrated a significant positive correlation between the drying rate and both the initial moisture content and the microwave power. However, the efficiency decreased due to material accumulation when the initial mass was excessive. The Page model provided the best fit for drying curves (highest R2 among models tested). The effective moisture diffusion coefficient increased with rising microwave power and water content. The activation energy for microwave drying was calculated as −14.3958 W/g, indicating a reduced dehydration energy barrier under microwave heating. Energy efficiency analysis revealed that increasing power and initial water content significantly reduced unit energy consumption. This study establishes a robust theoretical foundation and proposes actionable guidelines for optimizing energy-efficient and environmentally safe drying protocols in zinc-laden waste slag treatment.Abstract
Crude zinc oxide, as a by-product of zinc smelting operations, is a recoverable secondary zinc resource that necessitates moisture removal through drying processes prior to its industrial-scale recycling applications. In this study, the crude zinc oxide is treated using microwave drying technology, and its drying kinetic characteristics are thoroughly investigated. By systematically regulating the parameters of initial mass, microwave power, and initial water content, the effects on drying rate, effective diffusion coefficient, and energy efficiency are comprehensively analyzed. The experimental results demonstrated a significant positive correlation between the drying rate and both the initial moisture content and the microwave power. However, the efficiency decreased due to material accumulation when the initial mass was excessive. The Page model provided the best fit for drying curves (highest R2 among models tested). The effective moisture diffusion coefficient increased with rising microwave power and water content. The activation energy for microwave drying was calculated as −14.3958 W/g, indicating a reduced dehydration energy barrier under microwave heating. Energy efficiency analysis revealed that increasing power and initial water content significantly reduced unit energy consumption. This study establishes a robust theoretical foundation and proposes actionable guidelines for optimizing energy-efficient and environmentally safe drying protocols in zinc-laden waste slag treatment
Bridging the Green Marketing Communication Gap: Assessing Image Coherence in Green Hotels
No full textAbstract
This study investigates the gap between how hotels present their sustainability efforts (projected green image) and how guests perceive them (perceived green image). Drawing on signaling theory and using a multiple-case approach, we combined content and sentiment analysis to examine communication strategies and guest responses. The findings reveal frequent misalignments: some practices are promoted but not noticed (greenwashing risk), while others are valued by guests but undercommunicated (greenhushing). Based on these patterns, we propose a two-dimensional framework that maps four communication scenarios. The concept of green cohering—where projection and perception align—emerges as the ideal state for building credibility and trust. By introducing this framework, the study contributes to green marketing literature and offers practical guidance for hospitality businesses seeking to align sustainability messaging with guest experience. Our analysis highlights the need for communication strategies that are both operationally grounded and perceptually resonant.Abstract
This study investigates the gap between how hotels present their sustainability efforts (projected green image) and how guests perceive them (perceived green image). Drawing on signaling theory and using a multiple-case approach, we combined content and sentiment analysis to examine communication strategies and guest responses. The findings reveal frequent misalignments: some practices are promoted but not noticed (greenwashing risk), while others are valued by guests but undercommunicated (greenhushing). Based on these patterns, we propose a two-dimensional framework that maps four communication scenarios. The concept of green cohering—where projection and perception align—emerges as the ideal state for building credibility and trust. By introducing this framework, the study contributes to green marketing literature and offers practical guidance for hospitality businesses seeking to align sustainability messaging with guest experience. Our analysis highlights the need for communication strategies that are both operationally grounded and perceptually resonant
Evolution of thermal dehydration kinetics and thermophysical behavior of prepared Yb2O3 and Y2O3 co-stabilized ZrO2 materials during microwave-assisted co-precipitation method
No full textAbstract
In this study, co-precipitation and microwave calcination were used to create Yb2O3-Y2O3-ZrO2 nanocomposites. The samples were examined to analyze their phase composition, chemical bonding, morphology particle size, and nanoscale crystallinity. Thermal dehydration and phase transition behaviors were investigated by simultaneous thermal analysis. The Kissinger-Akahira-Sunoes (KAS), Ozawa-Flynn-Wall (OFW), and Starink models were used to determine the energy of activation energy (Ea) and pre-exponential factor (A) of the thermal dehydration process. The average activation energies calculated by the KAS, OFW, and Starink methods were 40.18, 43.88, and 40.10 kJ/mol, respectively. The OFW method provided the best fitting effect, with the highest mean pre-exponential factor (1.93 × 106 min−1), the lowest standard deviation (0.079), and its superior correlation coefficients (R2 = 0.948–0.963) compared to KAS and Starink. The “Master Plots Method” identified the dehydration mechanism as a reaction of first-order G(α) = -ln(1-α), corresponding to stochastic nucleation. Microwave calcination at 500 °C transformed amorphous precursors into a cubic-dominated phase (with minor tetragonal ZrO2) without monoclinic formation, while 1000 °C calcination enhanced crystallinity and particle uniformity. The analysis of the microstructure evolution and thermal dehydration kinetics of Yb2O3-Y2O3-ZrO2 nanocomposites in this study will contribute to the development of high-performance zirconia ceramics.Abstract
In this study, co-precipitation and microwave calcination were used to create Yb2O3-Y2O3-ZrO2 nanocomposites. The samples were examined to analyze their phase composition, chemical bonding, morphology particle size, and nanoscale crystallinity. Thermal dehydration and phase transition behaviors were investigated by simultaneous thermal analysis. The Kissinger-Akahira-Sunoes (KAS), Ozawa-Flynn-Wall (OFW), and Starink models were used to determine the energy of activation energy (Ea) and pre-exponential factor (A) of the thermal dehydration process. The average activation energies calculated by the KAS, OFW, and Starink methods were 40.18, 43.88, and 40.10 kJ/mol, respectively. The OFW method provided the best fitting effect, with the highest mean pre-exponential factor (1.93 × 106 min−1), the lowest standard deviation (0.079), and its superior correlation coefficients (R2 = 0.948–0.963) compared to KAS and Starink. The “Master Plots Method” identified the dehydration mechanism as a reaction of first-order G(α) = -ln(1-α), corresponding to stochastic nucleation. Microwave calcination at 500 °C transformed amorphous precursors into a cubic-dominated phase (with minor tetragonal ZrO2) without monoclinic formation, while 1000 °C calcination enhanced crystallinity and particle uniformity. The analysis of the microstructure evolution and thermal dehydration kinetics of Yb2O3-Y2O3-ZrO2 nanocomposites in this study will contribute to the development of high-performance zirconia ceramics
Deep and efficient removal of lead ions by zinc-graphite combination purifying agent from ZnCl2-NH4Cl-H2O system
No full textAbstract
Efficient recovery of metals from secondary resources is essential to address resource shortages and environmental crises. Recovery of secondary zinc resources is usually treated by hydrometallurgical processes, with ammonia treatment being a preferred option due to its advantages of selective leaching and recycling. However, ammonia leach solutions often contain high levels of lead, which hinder zinc electrowinning and require urgent purification. In this paper, a novel proposal was made to use a zinc-graphite composite purifier to remove lead ions from ammonia leach solution in depth and with high efficiency. Experimental results demonstrate significant zinc savings and lead removal efficiencies, the use of zinc-graphite to purify the solutions containing 0.075 and 0.2 g/L of lead can save 33.3 % and 56.7 % of zinc, respectively, and achieve a lead removal ratio of more than 98.7 %. The enhancement mechanism of graphite on lead ion removal efficiency may exist for two reasons. Firstly, when graphite is present, the purification residue forms a flocculent, loose and porous precipitate, which reduces the wrapping of zinc particles by the purification residue. In addition to this, the added graphite is electrically conductive and has the effect of transferring electrons, accelerating the replacement efficiency of zinc for lead. Overall, this work proposes a deep and highly efficient scheme for the removal of lead ions from ammoniacal leach solution by adding graphite, and the enhancement mechanism of graphite is also analyzed. The scheme presents an innovative and widely applicable solution for lead ion removal, with potential applications in other solution purifications.Abstract
Efficient recovery of metals from secondary resources is essential to address resource shortages and environmental crises. Recovery of secondary zinc resources is usually treated by hydrometallurgical processes, with ammonia treatment being a preferred option due to its advantages of selective leaching and recycling. However, ammonia leach solutions often contain high levels of lead, which hinder zinc electrowinning and require urgent purification. In this paper, a novel proposal was made to use a zinc-graphite composite purifier to remove lead ions from ammonia leach solution in depth and with high efficiency. Experimental results demonstrate significant zinc savings and lead removal efficiencies, the use of zinc-graphite to purify the solutions containing 0.075 and 0.2 g/L of lead can save 33.3 % and 56.7 % of zinc, respectively, and achieve a lead removal ratio of more than 98.7 %. The enhancement mechanism of graphite on lead ion removal efficiency may exist for two reasons. Firstly, when graphite is present, the purification residue forms a flocculent, loose and porous precipitate, which reduces the wrapping of zinc particles by the purification residue. In addition to this, the added graphite is electrically conductive and has the effect of transferring electrons, accelerating the replacement efficiency of zinc for lead. Overall, this work proposes a deep and highly efficient scheme for the removal of lead ions from ammoniacal leach solution by adding graphite, and the enhancement mechanism of graphite is also analyzed. The scheme presents an innovative and widely applicable solution for lead ion removal, with potential applications in other solution purifications