bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of Electronic Waste Components through X-ray and Neutron-Based Imaging Techniques
Authors: Buczkó Noémi Anna , Papp Mariann , Maróti Boglárka , Kis Zoltán , Szentmiklósi László
Published: September 2024

In modern society, the amount of e-waste is growing year by year. Waste electronic items are complex, highly heterogeneous systems, containing organic material as well as several exotic, valuable, toxic, mostly metallic elements. In this study, the potential of X-ray and neutron radiography to reveal the inner structure of various complex e-waste was investigated. The images obtained using the two techniques were evaluated together to investigate the possibility of a more efficient segmentation of the individual components. The advantages and limitations of the two methods were identified for the studied waste types. X-ray radiography was found to be preferable for the identification of small metallic parts and for revealing the internal structure of e-waste with thick plastic coatings. Neutron radiography allowed for the identification of several components that did not provide sufficient contrast with X-ray imaging due to their similar X-ray attenuation compared to their surroundings. The combination of the two methods opens up new opportunities and could provide much more effective segmentation than either method alone.
Mixed-Curve Model for Evaluating the Carbonation Depth of Concrete at Different Ages
Authors: Wang Xinhao , Yang Qiuwei , Cao Hongfei , Qin Fengjiang
Published: September 2024

To accurately quantify the variation in concrete carbonation depth, selecting an appropriate mathematical curve model is crucial. Currently prevalent models, such as the Fick model and exponential models, confront limitations in prediction accuracy and range of application. Given that a single curve model struggles to precisely describe the pattern of concrete carbonation, this work introduces a mixed-curve-based prediction model for carbonation depth, effectively integrating the Fick model with a hyperbolic model. Compared to the Fick model, the additional term in the mixed-curve model can be viewed as a reasonable correction to better adapt to the complex and varied conditions of concrete carbonation. This hybrid model transcends the limitations of individual models, enhancing fitting precision and broadening the scope of applicability. The new model boasts a concise structure with only two fitting parameters, facilitating ease of application. To validate its superiority, rigorous comparisons were conducted between the proposed model and existing ones, leveraging experimental data from 10 distinct concrete carbonation scenarios. By comparing the average error, standard deviation, and coefficient of determination across these cases, the new model demonstrates a clear advantage over the Fick model and the exponential model. In terms of fitting errors, the average error and standard deviation of the new model are notably lower than those of the other two models. In terms of the coefficient of determination, the values achieved by the new model in all examples are closer to 1 than those of both the Fick model and the exponential model, underscoring the new model’s superior fitting quality and remarkable stability. This research indicates that the combined model presented in this paper holds promising prospects for widespread application in predicting concrete carbonation depth.
Mechanical Properties and Chloride Penetration Resistance of Concrete Combined with Ground Granulate Blast Furnace Slag and Macro Synthetic Fiber
Authors: Cheng Shengzhao , Shen Lisha , Chen Weige , Zhu Haitang , You Peibo , Chen Lu
Published: September 2024

Concrete with good mechanical properties and durability has always been a necessity in engineering. The addition of fibers and supplementary cementitious materials to concrete can enhance its mechanical and durability performance through a series of chemical and physical interactions. This study aims to investigate the effects of key parameters on the compressive strength, splitting tensile strength, and chloride penetration resistance of concrete combined with ground granulate blast furnace slag (GGBS) and macro polypropylene synthetic fiber (MSF). Based on the Taguchi method, a total of eighteen mixtures were evaluated, considering the effects of GGBS content, MSF content, water-to-binder (w/b) ratio, and chloride solution concentration on concrete properties. The results showed that the w/b ratio has a significant impact on the properties of concrete, which are enhanced by a decrease in w/b ratio. The GGBS content had little effect on the 28-day strength of concrete, which even decreased with a large GGBS content, but GGBS had a positive effect on the long-term strength of concrete. Moreover, the chloride penetration resistance of concrete was enhanced by an increase in the GGBS content. The MSF content had no obvious effects on the compressive strength and chloride penetration resistance of concrete, but it could enhance the splitting tensile strength to some extent, and this enhancement was more obvious over time. The chloride diffusion coefficient of concrete changed with the concentration of chloride solution, and the two increased simultaneously.
Comparison of Flexural Strength and Wear of Injectable, Flowable and Paste Composite Resins
Authors: Rajabi Hadi , Denny Michael , Karagiannopoulos Kostas , Petridis Haralampos
Published: September 2024

(1) Objectives: This study investigated and compared the wear and flexural strength of two highly filled (injectable), one flowable and one paste composite. (2) Methods: Two highly filled flowable composites (G-aenial Universal Injectable and Beautifil Plus F00), a paste composite (Empress Direct) and a conventional flowable (Tetric EvoFlow) were tested. A two-body wear test was carried out using 10 disc-shaped samples from each group, which were subjected to 200,000 wear machine cycles to simulate wear, followed by Scanning Electron Microscope analysis. Flexural strength was tested using a three-point bend test using 15 beam samples for each of the four groups. Values were statistically compared using one-way analysis of variance (ANOVA) for flexural strength and a Kruskal–Wallis test for wear. (3) Results: The median volume loss for G-aenial Universal Injectable and Beautifil Plus F00 was statistically lower than that of both Empress Direct and Tetric EvoFlow. For flexural strength the two highly filled flowable composites both exhibited statistically higher mean flexural strength values compared to Empress Direct (p < 0.004) and Tetric Evoflow (p < 0.001). There were no statistically significant differences in the values of wear and flexural strength between the two highly filled flowable composites. (4) Conclusions/significance: Highly filled flowable composite resins with nano filler particles outperformed a conventional flowable and a paste composite resin in terms of wear resistance and flexural strength, and may be suitable to use in occlusal, load-bearing areas.
Giant Elastocaloric Effect and Improved Cyclic Stability in a Directionally Solidified (Ni50Mn31Ti19)99B1 Alloy
Authors: Wang Honglin , Wang Yueping , Zhang Guoyao , Li Zongbin , Yang Jiajing , Li Jinwei , Yang Bo , Yan Haile , Zuo Liang
Published: September 2024

Superelastic shape memory alloys with an integration of large elastocaloric response and good cyclability are crucially demanded for the advancement of solid-state elastocaloric cooling technology. In this study, we demonstrate a giant elastocaloric effect with improved cyclic stability in a <001>A textured polycrystalline (Ni50Mn31Ti19)99B1 alloy developed through directional solidification. It is shown that large adiabatic temperature variation (|ΔTad|) values more than 15 K are obtained across the temperature range from 283 K to 373 K. In particular, a giant ΔTad up to −27.2 K is achieved by unloading from a relatively low compressive stress of 412 MPa at 303 K. Moreover, persistent |ΔTad| values exceeding 8.5 K are sustained for over 12,000 cycles, exhibiting a very low attenuation behavior with a rate of 7.5 × 10−5 K per cycle. The enhanced elastocaloric properties observed in the present alloy are ascribed to the microstructure texturing as well as the introduction of a secondary phase due to boron alloying.
Molecular Dynamics Study on the Sintering Mechanism and Tensile Properties of Novel Cu Nanoparticle/Graphene Nanoplatelet Composite Solder Paste
Authors: Zhang Xuezhi , Gao Jian , Zhang Lanyu , Chen Yun , Zhang Yu , Zhang Kai
Published: September 2024

The sintering process of Cu nanoparticle (Cu NP)/graphene nanoplatelet (GNP) composite solder paste was thoroughly investigated in this work through molecular dynamics simulations. The tensile properties of the sintered Cu NP/GNP composite solder paste were considered by using the uniaxial quasi-static tensile simulation method. The impact of sintering temperature, strain rate, and GNP addition on the tensile properties of Cu NP/GNP sintered structures was thoroughly investigated. The lattice structure, dislocation evolution, and atomic diffusion of the molecular dynamics results were analyzed using the common neighbor analysis (CNA), dislocation extraction algorithm (DXA), and mean square displacement (MSD) methods. The results of the post-processing analysis showed that the addition of GNP and the sintering temperature have an important influence on the mechanical properties of Cu NP/GNP sintered structures. In addition, the incorporation of GNP can significantly improve the mechanical properties of sintered Cu NP/GNP composite solder paste. More specifically, the tensile strength and fracture strain of the sintered composite solder paste will be increased by increasing the tensile strain rate. The strengthening mechanism of the sintered Cu NP/GNP composite solder paste can be attributed to the dislocation strengthening mechanism. Our study provides valuable insight for the development of high-performance composite solder paste with enhanced mechanical properties.
Influence of Calcination and Cation Exchange (APTES) of Bentonite-Modified Reinforced Basalt/Epoxy Multiscale Composites’ Mechanical and Wear Performance: A Comparative Study
Authors: Khandelwal Saurabh , Dhand Vivek , Bae Jaehoon , Kim Taeho , Kim Sanghoon
Published: September 2024

In this study, bentonite clay was modified through silane treatment and calcination to enhance its compatibility with basalt fiber (BF) and epoxy in multiscale composites. The as-received bentonite (ARB) was subjected to silane treatment using APTES, producing silane-modified bentonite (STB), while calcination yielded calcined bentonite (CB). The modified clays were incorporated into basalt fiber-reinforced epoxy (BFRP) composites, which were fabricated using the vacuum-assisted resin transfer method (VARTM). Analytical techniques, including X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the structural changes in the clays. BET surface area analysis revealed a 314% increase in the surface area of STB and a 176% increase for CB. The modified clays also demonstrated reduced hydrophilicity and swelling behavior. Thermogravimetric analysis (TGA) indicated a minimal improvement in thermal stability, with the degradation onset temperatures increasing by less than 3 °C. However, tensile tests showed significant gains, with CB- and STB-reinforced composites achieving 48% and 21% higher tensile strength than ARB-reinforced composites. Tribological tests revealed substantial reductions in wear, with CB- and STB-reinforced composites showing 90% and 84% decreases in the wear volume, respectively. These findings highlight the potential of modified bentonite clays to improve the mechanical and wear properties of basalt fiber–epoxy composites.
Current Status of Research on Fault Diagnosis Using Machine Learning for Gear Transmission Systems
Authors: Fu Xuezhong , Fang Yuanxin , Xu Yingqiang , Xu Haijun , Ma Guo , Peng Nanjiang
Published: September 2024

Gear transmission system fault diagnosis is crucial for the reliability and safety of industrial machinery. The combination of mathematical signal processing methods with deep learning technology has become a research hotspot in fault diagnosis. Firstly, the development and status of gear transmission system fault diagnosis are outlined in detail. Secondly, the relevant research results on gear transmission system fault diagnosis are summarized from the perspectives of time-domain, frequency domain, and time-frequency-domain analysis. Thirdly, the relevant research progress in shallow learning and deep learning in the field of fault diagnosis is explained. Finally, future research directions for gear transmission system fault diagnosis are summarized and anticipated in terms of the sparsity of signal analysis results, separation of adjacent feature components, extraction of weak signals, identification of composite faults, multi-factor combinations in fault diagnosis, and multi-source data fusion technology.
A Principled Framework to Assess the Information-Theoretic Fitness of Brain Functional Sub-Circuits
Authors: Duong-Tran Duy , Nguyen Nghi , Mu Shizhuo , Chen Jiong , Bao Jingxuan , Xu Frederick H. , Garai Sumita , Cadena-Pico Jose , Kaplan Alan David , Chen Tianlong , Zhao Yize , Shen Li , Goñi Joaquín
Published: September 2024

In systems and network neuroscience, many common practices in brain connectomic analysis are often not properly scrutinized. One such practice is mapping a predetermined set of sub-circuits, like functional networks (FNs), onto subjects’ functional connectomes (FCs) without adequately assessing the information-theoretic appropriateness of the partition. Another practice that goes unchallenged is thresholding weighted FCs to remove spurious connections without justifying the chosen threshold. This paper leverages recent theoretical advances in Stochastic Block Models (SBMs) to formally define and quantify the information-theoretic fitness (e.g., prominence) of a predetermined set of FNs when mapped to individual FCs under different fMRI task conditions. Our framework allows for evaluating any combination of FC granularity, FN partition, and thresholding strategy, thereby optimizing these choices to preserve the important topological features of the human brain connectomes. By applying to the Human Connectome Project with Schaefer parcellations at multiple levels of granularity, the framework showed that the common thresholding value of 0.25 was indeed information-theoretically valid for group-average FCs, despite its previous lack of justification. Our results pave the way for the proper use of FNs and thresholding methods, and provide insights for future research in individualized parcellations.
Harmonic Synthesis on Group Extensions
Authors: Székelyhidi László
Published: September 2024

Harmonic synthesis describes translation invariant linear spaces of continuous complex valued functions on locally compact abelian groups. The basic result due to L. Schwartz states that such spaces on the reals are topologically generated by the exponential monomials in the space; in other words, the locally compact abelian group of the reals is synthesizable. This result does not hold for continuous functions in several real variables, as was shown by D.I. Gurevich’s counterexamples. On the other hand, if two discrete abelian groups have this synthesizability property, then so does their direct sum, as well. In this paper, we show that if two locally compact abelian groups have this synthesizability property and at least one of them is discrete, then their direct sum is synthesizable. In fact, more generally, we show that any extension of a synthesizable locally compact abelian group by a synthesizable discrete abelian group is synthesizable. This is an important step toward the complete characterization of synthesizable locally compact abelian groups.
A Network Reliability Analysis Method for Complex Real-Time Systems: Case Studies in Railway and Maritime Systems
Authors: Zang Yu , E Jiaxiang , Fiondella Lance
Published: September 2024

The analysis of complex system reliability is an area of growing interest, particularly given the diverse and intricate nature of the subsystems and components these systems encompass. Tackling the reliability of such multifaceted systems presents challenges, including component wear, multiple failure modes, the cascading effects of these failures, and the associated uncertainties, which require careful consideration. While traditional studies have examined these elements, the dynamic interplay of information between subsystems and the overarching system has only recently begun to draw focus. A notably understudied aspect is the reliability analysis of complex real-time systems that must adapt to evolving operational conditions. This paper proposes a novel methodology for assessing the reliability of complex real-time systems. This method integrates complex network theory, thus capturing the intricate operational characteristics of these systems, with adjustments to several key complex network parameters to define the nuances of communication within the network framework. To showcase the efficacy and adaptability of our approach, we present case studies on railway and maritime systems. For the railway system, our analysis spans various operational scenarios: from single train operations to simultaneous operations across multiple or different radio block center regions, accounting for node and edge failures. In maritime systems, the case studies employing the VHF data exchange system under operational scenarios are subject to network reliability analysis, successfully pinpointing critical vulnerabilities and modules of high importance. The findings of our research are promising, demonstrating that the proposed method not only accurately evaluates the overall reliability of complex systems but also identifies the pivotal weak points—be it modules or links—warranting attention for system enhancement.
Mechanical Instabilities and the Mathematical Behavior of van der Waals Gases
Authors: Pennini Flavia , Plastino Angelo
Published: September 2024

We explore the mathematical behavior of van der Waals gases at temperatures where classical descriptions are inadequate due to emerging quantum effects. Specifically, we focus on temperatures T2 at which the thermal de Broglie wavelength becomes comparable to the interparticle spacing, signifying the onset of quantum mechanical influences. At such temperatures, we find that the isothermal compressibility of the gas becomes negative, indicating mechanical instability. In the pressure–density diagrams, we note that the pressure can become negative at small densities, illustrating the limitations of classical models and the necessity for quantum mechanical approaches. These phenomena serve as clear indicators of the transition from classical thermodynamics to quantum statistical mechanics. The observed mechanical instability and negative pressures represent rare macroscopic manifestations of quantum effects, demonstrating their profound impact on gas behavior. Our study highlights the significant role of emerging quantum properties on observable macroscopic scales, particularly for van der Waals gases at low temperatures and small densities. Additionally, we discuss the theoretical implications of our findings, underlining the limitations of the van der Waals model under extreme conditions and emphasizing the critical need to include quantum corrections in thermodynamic frameworks.
Deep Reinforcement-Learning-Based Air-Combat-Maneuver Generation Framework
Authors: Mei Junru , Li Ge , Huang Hesong
Published: September 2024

With the development of unmanned aircraft and artificial intelligence technology, the future of air combat is moving towards unmanned and autonomous direction. In this paper, we introduce a new layered decision framework designed to address the six-degrees-of-freedom (6-DOF) aircraft within-visual-range (WVR) air-combat challenge. The decision-making process is divided into two layers, each of which is addressed separately using reinforcement learning (RL). The upper layer is the combat policy, which determines maneuvering instructions based on the current combat situation (such as altitude, speed, and attitude). The lower layer control policy then uses these commands to calculate the input signals from various parts of the aircraft (aileron, elevator, rudder, and throttle). Among them, the control policy is modeled as a Markov decision framework, and the combat policy is modeled as a partially observable Markov decision framework. We describe the two-layer training method in detail. For the control policy, we designed rewards based on expert knowledge to accurately and stably complete autonomous driving tasks. At the same time, for combat policy, we introduce a self-game-based course learning, allowing the agent to play against historical policies during training to improve performance. The experimental results show that the operational success rate of the proposed method against the game theory baseline reaches 85.7%. Efficiency was also outstanding, with an average 13.6% reduction in training time compared to the RL baseline.
Red Seaweed (Rhodophyta) Phycocolloids: A Road from the Species to the Industry Application
Authors: Mendes Madalena , Cotas João , Pacheco Diana , Ihle Kay , Hillinger Alina , Cascais Miguel , Marques João Carlos , Pereira Leonel , Gonçalves Ana M. M.
Published: September 2024

Seaweed polysaccharides are versatile both in their functions in seaweed physiology and in their practical applications in society. However, their content and quality vary greatly. This review discusses the main factors that influence the yield and quality of polysaccharides, specifically carrageenans and agars (sulfated galactans) found in red algae species (Rhodophyta). In addition, its historical, current, and emerging applications are also discussed. Carrageenan has been influenced mainly by photosynthetically active radiation (PAR) and nitrogen, while its relationship with temperature has not yet been replicated by recent studies. Agar’s seasonal trend has also been found to be more ambiguous than stated before, with light, temperature, nutrients, and pH being influencing factors. In this review, it is also shown that, depending on the compound type, seaweed polysaccharides are influenced by very different key factors, which can be crucial in seaweed aquaculture to promote a high yield and quality of polysaccharides. Additionally, factors like the extraction method and storage of polysaccharides also influence the yield and quality of these compounds. This review also highlights the drawbacks and inadequacy inherent from the conventional (or current) extraction technology approaches.
Enhancing Electrospinnability of Chitosan Membranes in Low-Humidity Environments by Sodium Chloride Addition
Authors: Su Hengjie , Chen Xiaoqi , Mao Linna , Li Ting
Published: September 2024

The electrospinning of pure chitosan nanofibers is highly sensitive to environmental humidity, which limits their production consistency and applicability. This study investigates the addition of sodium chloride (NaCl) to chitosan solutions to enhance spinnability and mitigate the effigurefects of low humidity. NaCl was incorporated into the electrospun chitosan solution, leading to increased conductivity and decreased viscosity. These modifications improved the electrospinning process. Comparative analyses between chitosan membranes (CM) and sodium-chloride-added chitosan membranes (SCM) revealed no significant differences in chemical structure, mechanical strength, or in vitro cell proliferation. This indicates that the addition of 1% (w/v) NaCl does not adversely affect the fundamental properties of the chitosan membranes. The findings demonstrate that NaCl addition is a viable strategy for producing electrospun chitosan nanofibers in low-humidity environments, maintaining their physicochemical properties while enhancing spinnability.
Critical Resolved Shear Stress and Work Hardening Determination in HCP Metals: Application to Zr Single Crystals
Authors: Lecomte Jean-Sébastien , Crépin Jérôme , Barberis Pierre
Published: September 2024

Obtaining precise parameters of deformation modes remains a significant challenge in materials science research. Critical resolved shear stresses (CRSS) and work hardening, particularly in hexagonal metals, are crucial parameters for constitutive laws in crystal plasticity. This paper presents a novel approach to determine CRSS and specific hardening matrix coefficients for commercially pure zirconium (α-Zr) at room temperature. In situ methods are employed to measure displacement fields using grids applied to the sample surface, while a comprehensive characterization of the activated deformation systems is performed via SEM and TEM. The CRSS for prismatic ⟨a⟩, pyramidal ⟨a⟩, and 101¯2 and 112¯1 twinning systems, as well as the self-hardening for prismatic slip and several work-hardening coefficients (for prismatic/prismatic and prismatic/pyramidal interactions), are reported in Zr single crystals. Finally, the results are compared with findings from the literature and atomistic simulations.
The Causal Effect of Urate Level on Female Infertility: A Mendelian Randomization Study
Authors: Sun Jiawei , Shen Ting , Guan Yining , Jiang Yixin , Xu Xiaoling
Published: September 2024

Background/Objective: This study aimed to investigate the causal relationship between urate level and female infertility using Mendelian randomization (MR) analysis. Methods: To identify instrumental variables, we selected independent genetic loci associated with serum urate levels in individuals of European ancestry, utilizing data from large-scale genome-wide association studies (GWAS). The GWAS dataset included information on serum urate levels from 288,649 CKDGen participants. Female infertility data, including different etiologic classifications, consisted of 13,142 female infertility patients and 107,564 controls. We employed four MR methods, namely inverse variance weighted (IVW), MR-Egger, weighted median, and weighted model, to investigate the causal relationship between urate levels and female infertility. The Cochran Q-test was used to assess heterogeneity among single nucleotide polymorphisms (SNPs), and the MR-Egger intercept test was employed to evaluate the presence of horizontal pleiotropy. Additionally, a “leave-one-out” sensitivity analysis was conducted to examine the influence of individual SNPs on the MR study. Results: The IVW analysis demonstrated that elevated serum urate levels increased the risk of female infertility (odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.07–1.33). Furthermore, serum urate levels were found to be associated with infertility due to cervical, vaginal, or other unknown causes (OR = 1.16, 95% CI: 1.06–1.26), also confirmed by other methods. Heterogeneity among instrumental variables was assessed using Cochran’s Q-test (p < 0.05), so a random-effects IVW approach was employed in the effects model. The MR-Egger intercept test indicated no presence of horizontal pleiotropy. A “leave-one-out” sensitivity analysis was conducted, demonstrating that no individual SNP had a substantial impact on the overall findings. Conclusions: In the European population, the urate level is significantly and causally associated with an increased risk of female infertility.
Signal Denoising Method Based on EEMD and SSA Processing for MEMS Vector Hydrophones
Authors: Wang Peng , Dong Jie , Wang Lifu , Qiao Shuhui
Published: September 2024

The vector hydrophone is playing a more and more prominent role in underwater acoustic engineering, and it is a research hotspot in many countries; however, it also has some shortcomings. For the mixed problem involving received signals in micro-electromechanical system (MEMS) vector hydrophones in the presence of a large amount of external environment noise, noise and drift inevitably occur. The distortion phenomenon makes further signal detection and recognition difficult. In this study, a new method for denoising MEMS vector hydrophones by combining ensemble empirical mode decomposition (EEMD) and singular spectrum analysis (SSA) is proposed to improve the utilization of received signals. First, the main frequency of the noise signal is transformed using a Fourier transform. Then, the noise signal is decomposed by EEMD to obtain the intrinsic mode function (IMF) component. The frequency of each IMF component in the center further determines that the IMF component belongs to the noise IMF component, invalid IMF component, or pure IMF component. Then, there are pure IMF reserved components, removing noisy IMF components and invalid IMF components. Finally, the desalinated IMF reconstructs the signal through SSA to obtain the denoised signal, which realizes the denoising processing of the signal, extracting the useful signal and removing the drift. The role of SSA is to effectively separate the trend noise and the periodic vibration noise. Compared to EEMD and SSA separately, the proposed EEMD-SSA algorithm has a better denoising effect and can achieve the removal of drift. Following that, EEMD-SSA is used to process the data measured by Fenhe. The experiment is carried out by the North University of China. The simulation and lake test results show that the proposed EEMD-SSA has certain practical research value.
Efficacy of Virucidal Treatments against Poliovirus Type 1 Deposited on Stainless-Steel Carriers
Authors: Chiossone Cory , Kapes Tanya , Good Robert , Nims Raymond W. , Zhou S. Steve
Published: September 2024

Safe containment of infectious poliovirus (PV) within Poliovirus-Essential Facilities (PEFs) will require the implementation of reliable PV-inactivation approaches for decontaminating work surfaces. Such approaches should be demonstrated empirically to display adequate efficacy at the use temperature, and the contact times required should be characterized to ensure efficacy. Such efficacy is judged by the ability of the inactivation approach to completely inactivate any PV deposited, with the demonstrated total log10 reduction in PV titer being as high as empirically achievable. We screened several approaches for their efficacy in inactivating wild-type PV type 1 Chat strain experimentally deposited on stainless-steel carriers at room temperature. On the basis of the results, we selected two approaches (5000 ppm sodium hypochlorite in water and 95% v/v ethanol in water) for further characterization for repeatability of efficacy (log10 reduction in PV titer) and time kinetics of inactivation. We now report that both PV-inactivation approaches, which should be readily available to all PEF laboratories globally, fulfill the expectations expressed above, with 5000 ppm sodium hypochlorite reproducibly causing ≥5.38 log10 inactivation and 95% ethanol reproducibly causing ≥4.46 log10 inactivation of PV on stainless-steel surfaces within a 5 min contact time at room temperature.
A Novel Surface Passivation Method of Pyrite within Rocks in Underwater Environments to Mitigate Acid Mine Drainage at Its Source
Authors: Fan Lijun , Han Tiancheng , Huang Xianxing , Yang Yixuan , Zhu Tao , Zhai Weiwei , Zhang Daoyong , Pan Xiangliang
Published: September 2024

Mitigating acid mine drainage (AMD) at its source, specifically within rocks containing pyrite in underwater environments, poses a significant environmental challenge worldwide. Existing passivation techniques are primarily designed for open-air conditions, involving direct contact with coating materials at a solid–liquid interface, making them ineffective beneath a water barrier. In this study, we introduce a novel passivation method inspired by the design of underwater bio-adhesives. Tannic acid (TA) combined with polyethylene glycol (PEG) was employed to form a hydrophobic film directly on the pyrite surface, overcoming water resistance and addressing the limitations of current techniques. Electrochemical experiments and chemical leaching experiments were conducted to evaluate the oxidation resistance of the passivating films. TA–PEG-coated pyrite exhibited a lower oxidation rate and a higher static contact angle of 126.2°, achieving suppression efficiencies of 71.6% for total Fe release and 68.1% for total S release. A comprehensive characterization approach, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), was employed to investigate the passivation mechanism. The results of this study may provide new insights into the preparation of simpler and greener passivating agents to suppress pyrite oxidation at its source in underwater environments.
Parametrization of Geopolymer Compressive Strength Obtained from Metakaolin Properties
Authors: Taborda-Barraza Madeleing , Tambara Luis U. D. , Vieira Carlos M. , de Azevedo Afonso R. Garcez , Gleize Philippe J. P.
Published: September 2024

In the search for alternative cementitious materials, the alkali activation of aluminosilicates has been found to be a mechanically effective binder. Among precursors, metakaolin is most frequently used, with a primary source, kaolin, distributed globally in varying compositions. This variability may indicate potential compositional limitations for the large-scale production of such binders. Thus, four types of commercial calcined clays, activated under identical conditions, were evaluated, and their physicochemical characteristics were correlated with the mechanical properties of the resulting binder. Different characterization methods were used for the raw material and for each alkali-activated system. Anhydrous metakaolin was assessed through particle size distribution, specific surface area, zeta potential, vitreous phases, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), amorphism, and pozzolanic activity. The pastes were evaluated in the fresh state through apparent activation energy progression and isothermal conduction calorimetry, and in the hardened state through compressive strength and dilatometry. Compressive strength values ranged from 7 to 42 MPa. From these results, a mathematical model was developed to estimate mechanical performance based on key variables, specifically amorphism, the pozzolanic index, and the silica-to-alumina ratio. This model allows for performance predictions without the need to prepare additional pastes. Interestingly, it was found that while some systems displayed low initial reactivity, their relative reactivity over time increased more significantly than those with higher early-stage reactivity, suggesting their potential for reconsideration in long-term applications.
Study on the Influence of Host–Guest Structure and Polymer Introduction on the Afterglow Properties of Doped Crystals
Authors: Feng Wenhui , Lou Zongyong , Zhao Xiaoqiang , Zhao Mingming , Xu Yaqin , Gao Yide
Published: September 2024

Due to their low cost, good biocompatibility, and ease of structural modification, organic long-persistent luminescence (LPL) materials have garnered significant attention in organic light-emitting diodes, biological imaging, information encryption, and chemical sensing. Efficient charge separation and carrier migration by the host–guest structure or using polymers and crystal to build rigid environments are effective ways of preparing high-performance materials with long-lasting afterglow. In this study, four types of crystalline materials (MODPA: DDF-O, MODPA: DDF-CHO, MODPA: DDF-Br, and MODPA: DDF-TRC) were prepared by a convenient host–guest doping method at room temperature under ambient conditions, i.e., in the presence of oxygen. The first three types exhibited long-lived charge-separated (CS) states and achieved visible LPL emissions with durations over 7, 4, and 2 s, respectively. More surprisingly, for the DDF-O material prepared with PMMA as the polymer substrate, the afterglow time of DDF-O: PMMA was longer than 10 s. The persistent room-temperature phosphorescence effect caused by different CS state generation efficiencies and rigid environment were the main reason for the difference in LPL duration. The fourth crystalline material was without charge separation and exhibited no LPL because it was not a D-A system. The research results indicate that the CS state generation efficiency and a rigid environment are the key factors affecting the LPL properties. This work provides new understandings in designing organic LPL materials.
Design and Characterization of Epoxy Resin Systems Based on Mixtures of Imidazolium-Based Ionic Liquids with Docusate and Dicyanamide Anions
Authors: Szpecht Andrea , Zielinski Dawid , Roszyk Szymon , Smiglak Marcin
Published: September 2024

This study focuses on the synthesis, characterization, and application of four ionic liquids (ILs), three of which are being reported for the first time, with unique thermal properties and diverse anion-cation combinations, specifically in the context of epoxy resin polymerization. 1-3-Didodecylimidazolium dicyanamide (dDDIM DCA), 1-3-Didodecylimidazolium docusate (dDDIM DOSS), 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA), and 1-ethyl-3-methylimidazolium docusate (EMIM DOSS) were used to prepare six different mixtures with the same cation and with varying concentrations of DCA components, which is the main factor of an efficient polymerization, while the other component is intended to modify the properties of the cured resin. Mixtures based on EMIM cation demonstrated increased enthalpy and lower onset polymerization temperatures, indicating more efficient curing processes. The hardness of cured epoxy resins can be adjusted by altering the curing temperature and IL composition, with EMIM DCA and EMIM DOSS mixtures displaying high Shore A hardness, suitable for durable surface applications. In contrast, mixtures with higher dDDIM DCA proportions offered a balance between rigidity and flexibility, ideal for applications requiring both mechanical strength and elasticity.
Hollow Gold–Silver Nanorods—A New, Very Efficient Nanomaterial for Surface-Enhanced Raman Scattering (SERS) Measurements
Authors: Michałowska Aleksandra , Kudelski Andrzej
Published: September 2024

Anisotropic plasmonic nanoparticles usually generate SERS enhancement factors that are significantly larger than those generated by spherical plasmonic nanostructures, so the former are usually preferred as substrates for SERS measurements. Gold nanorods are one of the most commonly used anisotropic nanomaterials for SERS experiments. Unfortunately, even a slight contamination of the surfactant used in the process of the synthesis of gold nanorods has a significant impact on the geometry of the resulting nanostructures. In this work, using easily formed silver nanorods as templates, hollow AuAg nanorods are formed by means of a silver–gold galvanic exchange reaction (in this process, nanostructures with a cavity inside form because one gold atom replaces three silver atoms). Hollow AuAg nanorods are highly active during SERS measurements—for shorter wavelengths of the excitation radiation, they display greater SERS activity than Au nanorods. To our knowledge, this is the first example of the use of hollow plasmonic nanorods for SERS measurements. Elemental mapping of the rods showed that the silver, some of which remained after the galvanic replacement, is mainly located close to the internal cavity that was formed, whereas the gold is mainly located at the outermost regions of the nanostructure. This explains the high chemical stability of these nanostructures.
Effects of L-Proline on the Stability of Mulberry Anthocyanins and the Mechanism of Interaction between L-Proline and Cyanidin-3-O-Glycoside
Authors: Cui Haipeng , Li Xianbao , Ji Yuan , Zhao Shengxu , Yang Jianting
Published: September 2024

The protective effects of L-aspartic acid, L-valine, and L-proline on the stability of mulberry anthocyanins were investigated. Results showed that L-aspartic acid, L-valine, and L-proline significantly enhanced (p < 0.05) the stability of mulberry anthocyanins under constant light or ascorbic acid (AA). L-Proline had the best protective effect against anthocyanin degradation. The interaction between L-proline and cyanidin-3-O-glucoside (C3G) through hydrogen bonding and van der Waals forces, which improved the stability of C3G, was confirmed using FT-IR, 1H NMR, XRD, and molecular docking analyses, as well as molecular dynamics modes. In vitro digestion experiments yielded that both 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging capacities of the C3G/Pro group were increased in the intestinal fluid (p < 0.05). The above findings suggest that L-proline effectively slowed down the degradation of mulberry anthocyanins, and that it could be used as an auxiliary pigment and food additive to extend the optimal flavor period of products containing mulberry anthocyanins, and can improve the bioavailability of mulberry anthocyanins.
Selective Co(II) and Ni(II) Separation Using the Trihexyl(tetradecyl)phosphonium Decanoate Ionic Liquid
Authors: Kovačević Anđela , Ricardo García José Alejandro , Tolazzi Marilena , Melchior Andrea , Sanadar Martina
Published: September 2024

The room temperature ionic liquid trihexyl(tetradecyl)phosphonium decanoate ([P66614][Dec]) was employed in the liquid-liquid extraction of Co(II) from hydrochloric acid solutions in the presence of Ni(II). The extraction performance in liquid-liquid separations showed a strong dependence on the acid content of the feed aqueous solution. The best performance in terms of extracted cobalt and selectivity was obtained when the feed contained a HCl concentration above 6 M On the contrary, when the experiment was performed in absence of HCl, a lower extraction and Co/Ni selectivity were obtained. This behavior has been rationalized by considering the protonation of the [Dec]− anion and the different Co(II)/Ni(II) speciation in HCl media. Moreover, polymer inclusion membranes (PIMs) were prepared using PVC and [P66614][Dec] at different weight rations. Only the PIM formulated with a 30:70/PVC:[P66614][Dec] weight ratio demonstrated effective extraction of Co(II) from the HCl solution. The extraction efficiency and selectivity of the PIM was comparable to that from biphasic liquid experiments at 8 M HCl. The results of this study constitute a promising background for further practical developments of carboxylate-based ILs applied in Co/Ni separations.
The Influence of Rhizobial Nod Factors on the Synthesis of Flavonoids in Common Buckwheat (Fagopyrum esculentum Moench)
Authors: Kidaj Dominika , Zamlynska Katarzyna , Swatek Anita , Komaniecka Iwona
Published: September 2024

Flavonoids constitute a class of polyphenolic secondary metabolites synthesised mainly by plants and possessing anticancer, antioxidant, anti-inflammatory, and antiviral properties. Common buckwheat (F. esculentum Moench) is a dicotyledonous plant rich in different classes of flavonoids (e.g., rutin) and other phenolic compounds. Lipochitooligosaccharides (LCOs), i.e., rhizobial Nod factors and important signalling molecules for the initiation of symbiosis with legumes, are very effective mitogens that stimulate cell division in plant meristems and the production of secondary metabolites. They can also act in this way in non-legume plants. It has been shown that rhizobial Nod factors noticeably improve plant growth. Rhizobial Nod factors influence the production of flavonoids in common buckwheat grown in greenhouse conditions. The amount of rutin and isoorientin in leaves and flowers has been shown to increase in a statistically significant way after application of Nod factors to buckwheat seeds. The presence of rhizobial Nod factors has no influence on the flavonoid content in stems and roots.
Extraction and Synthesis of Typical Carotenoids: Lycopene, β-Carotene, and Astaxanthin
Authors: Jiang Yuxuan , Ye Jingyi , Hu Yadong , Zhang Jian , Li Wenhui , Zhou Xinghu , Yu Mingzhou , Yu Yiyang , Yang Jingwei , Yang Wenge , Jiang Jinchi , Cui Jie , Hu Yonghong
Published: September 2024

Carotenoids are tetraterpene compounds acting as precursors to vitamin A, with functions that include protecting eyesight, enhancing immunity, promoting cell growth and differentiation, and providing antioxidative benefits. Lycopene, β-carotene, and astaxanthin are particularly critical for health and have diverse applications in food, health products, and medicine. However, natural carotenoids are encased within cell structures, necessitating mechanical methods to disrupt the cell wall for their extraction and purification—a process often influenced by environmental conditions. Thus, improving the efficiency of carotenoid extraction from natural resources is of great interest. This review delves into the research progress made on the extraction processes, structures, and biological functions of carotenoids, focusing on lycopene, β-carotene, and astaxanthin. Traditional extraction methods primarily involve organic solvent-assisted mechanical crushing. With deeper research and technological advancements, more environmentally friendly solvents, advanced machinery, and suitable methods are being employed to enhance the extraction and purification of carotenoids. These improvements have significantly increased extraction efficiency, reduced preparation time, and lowered production costs, laying the groundwork for new carotenoid product developments.
Effective CO2 Thermocatalytic Hydrogenation with High Coke Resistance on Ni-CZ/Attapulgite Composite
Authors: Chen Shumei , Fu Jiacheng , Peng Yonghui , Liang Lixing , Ouyang Jing
Published: September 2024

Converting CO2 into methane is considered a promising and economically viable technology for global transportation and utilization of this greenhouse gas. This study involves the preparation of a Ni-CZ (CeO2-ZrO2)/ATP (attapulgite) catalyst through the co-precipitation and impregnation methods. XRD, SEM, TEM, N2 absorption-desorption isotherms, XPS, H2-TPR, CO2-TPD, TG/DSC, and Raman were adapted to characterize the obtained samples. Real-time GC was used to measure the catalytic performances and to intensively study the impact of Ni loading content and ATP to CZ ratio on the catalytic performance of the products. DRIFTs was used to monitor the interstitial radicals in the catalytic reactions and to deduce the catalytic mechanisms. The results indicate that the composite catalytic matrix composed of CZ assembled on ATP demonstrated higher CO2 methanation stability and better carbon deposition resistance ability than the single CZ or ATP as the carrier, which should be attributed to the improved specific surface area and pore volume of the ATP assembled matrix and the enhanced dispersibility of the CZ and Ni species. The adoption of CZ solid solutions improves the oxygen storage capability of the catalyst, thereby providing continued mobile O2− in the matrix and accelerating the molecular exchange rate in the catalytic reactions. The ideal loading quantity of nickel contents on the CZA matrix is 15%, as the CO2 conversion decreases at elevated temperatures when the Ni loading content reaches 20%. Among the tested samples, the 15Ni-0.8CZA sample showed the best catalytic performance of 75% CO2 conversion and 100% CH4 selectivity at 400 °C. After 50 h of stability tests, the CO2 conversion rate still remained 70.84%, and the CH4 selectivity obtained 97.46%. No obvious coke was detected according to the Raman spectra of the used catalyst. The in situ DRIFTS experiment showed that formate is the main intermediate of the CO2 hydrogenation reaction on the 15Ni-0.8CZA catalyst.