Nature Of Surface Research Articles

Analysis of heat transfer modes in the cooling of blocks generating different heat quantities

Achieving improved cooling efficiency and control in electronic components with varying heat outputs can be realized through a thorough analysis of different heat transfer modes, focusing on their contributions and interactions within the system. The analysis is conducted within a cavity containing three circular blocks generating varying amounts of heat. The blocks are affixed to an insulated plate, dividing the cavity into two identical sections with different fluids and different cooling mechanisms. In the open portion of the divided cavity, block cooling is achieved through forced convection using a nanofluid, while the closed section dissipates heat through natural convection and surface radiation. The numerical solution of the governing equations is performed using Galerkin's Finite Element Method, with detailed examination of the cooling process considering various parameters, such as block displacement (1.5cm≤y1≤3.25cm) and dimensions (0.25cm≤R≤1.5cm), Reynolds number (10≤Re≤1000), nanoparticles nature and volumetric fraction(0 %–10 %), emissivity (0≤ε≤1), thermal heat ratio(0.125 to 8), and cavity inclination angle(0°–180°). The results show that the combination of natural convection and surface radiation can be highly effective, rivaling forced convection in cooling the blocks. The study shows that an increase in the Reynolds number results in a temperature reduction of up to 6 °C, while increasing the emissivity leads to a more significant drop of around 10 °C. Additionally, miniaturizing the blocks by reducing their radius by a factor of six causes the maximum temperature to rise by over 20 °C.

Laser Direct Writing of Setaria Virids-Inspired Hierarchical Surface with TiO2 Coating for Anti-Sticking of Soft Tissue.

In minimally invasive surgery, the tendency for human tissue to adhere to the electrosurgical scalpel can complicate procedures and elevate the risk of medical accidents. Consequently, the development of an electrosurgical scalpel with an anti-sticking coating is critically important. Drawing inspiration from nature, we identified that the leaves of Setaria Virids exhibit exceptional non-stick properties. Utilizing this natural surface texture as a model, we designed and fabricated a specialized anti-sticking surface for electrosurgical scalpels. Employing nanosecond laser direct writing ablation technology, we created a micro-nano textured surface on the high-frequency electrosurgical scalpel that mimics the structure found on Setaria Virids leaves. Subsequently, a TiO2 coating was deposited onto the ablated scalpel surface via magnetron sputtering, followed by plasma-induced hydrophobic modification and treatment with octadecyltrichlorosilane (OTS) to enhance the surface's affinity for silicone oil, thereby constructing a self-lubricating and anti-sticking surface. The spreading behavior of deionized water, absolute ethanol, and dimethyl silicone oil on this textured surface is investigated to confirm the effectiveness of the self-lubrication mechanism. Furthermore, the sticking force and quality are compared between the anti-sticking electrosurgical scalpel and a standard high-frequency electrosurgical scalpel to demonstrate the efficacy of the nanosecond laser-ablated micro-nano texture in preventing sticking. The findings indicate that the self-lubricating anti-sticking surface fabricated using this texture exhibits superior anti-sticking properties.

Evaluation of a binary amphiphile/solvent mixture for the formulation of an ecological detergent as an alternative for removing fat from natural fiber surfaces

The application of a binary amphiphile/solvent blend composed of a natural surfactant (alkyl polyglucoside) and the green solvent ethyl lactate (EL) as an active component in the formulation of a new ecological detergent has improved the washing process conditions. Foaming properties of the detergent were optimal, with foam stability (R5) values of 76.17% and 78.61% for the best formulations. It is common practice to add substances that can regulate the pH to 9 to enhance the washing efficiency. This was reflected in the results of this study, where pH and the interaction between pH and surfactant type significantly influenced the percentage of residual fat. Currently, commercial detergents recommend a 1% dilution. However, studies have evaluated a 0.5% dilution. Therefore, it opted to evaluate new concentrations of 0.4% and 0.3%. Optimization of the factorial design resulted in dirt removal rates exceeding 91%, while the lowest percentage of residual fat (< 0.37%) was achieved at 25 °C, pH 9, and 0.3% detergent doses without lipase. Furthermore, illustrations of the surface morphology of the washed fibers demonstrated that the samples were not adversely affected by the formulated detergent or the washing process conditions. The alkyl polyglucoside/ethyl lactate binary blend was shown for the first time to exhibit strong interactions, possessing excellent residual fat and soil removal properties, suggesting its potential use in the formulation of green detergents for washing natural and synthetic textile fibers as a replacement for detergents based on ethoxylated fatty alcohols.

Performance Evaluation of a Romanian Zeolite: A Sustainable Material for Removing Ammonium Ions from Water

Ammonium ion is a chemical species that is found in abundance in natural waters, whether underground or surface, but also in wastewater resulting from agricultural and industrial activities. Even if the removal of the ammonium ion from water has been studied for a very long time, it has been found that its removal is far from being solved. In this study, we evaluated the performance of the ammonium ion adsorption process on two adsorbents, zeolite clinoptilolite, ZR, a sustainable material (manufacturer: Zeolite Development SRL, Rupea, Brasov, Romania), and the other granular activated carbon type, Norit GAC 830 W. Zeolite ZR is found in very large deposits in Romania; it is a natural, cheap material with costs between 50 and 100 EUR/ton, compared to other adsorbents that cost over 500 EUR/ton and which can be regenerated and reused in the technological process of water treatment and purification, but also after exhaustion, as an amendment for the soil. In the first step, this paper presents the mineralogic (XRD) and structural (SEM and EDX) characterization of the ZR and the determination of the pH zero-point charge, pHZPC, for all the adsorbents. Studies were carried out in equilibrium and kinetic conditions. The efficiency of the adsorbent was investigated in different experimental conditions by varying the initial concentration, particle size, temperature, pH, ionic strength, and contact time. The mathematical models and parameters specific to the adsorption isotherms that best describe the experimental results were identified. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich mathematical models were used for comparison. The Langmuir isotherm proved to be the most appropriate to describe the adsorption of ammonium ions on all types of adsorbents used. The adsorption capacity of ammonium ions from synthetic solutions at 20 °C, pH = 6.09, for the range of initial concentrations 0–50 mg/L for Rupea zeolite is in the range of 10.46 mg/g−12.34 mg/g, and for granular activated carbon GAC W830, it is 16.64 mg/g. It was found that the adsorption capacity of the ammonium ion on both activated carbon and zeolite increases with increasing temperature and pH. Also, it was observed that as the ionic strength increases, the adsorption capacity decreases for all four adsorbents. Kinetic models were also identified that best describe the experimental processes. In this sense, pseudo-first order, pseudo-second order, intra-particle diffusion and the Elovich model were used. The results of the investigation showed that second-order kinetics governs the adsorption process on ZR, and pseudo-first order governs activated carbon.

Effects of stress-relief and natural aging on the geometric tolerances and functional requirements of ferritic nitrocarburized gray cast iron brake rotors

Gray cast iron (GCI) brake rotors are prone to corrosion, particularly in electric vehicles (EVs), owing to their regenerative braking systems. Ferritic nitrocarburizing (FNC) heat treatment has been used to improve the corrosion resistance and cleanability of GCI rotors. However, pre-existing residual stresses in the rotors can lead to distortion after FNC processing, thereby affecting the functional and tolerance requirements. This study investigated the effects of stress-relief (SR) heat treatment and natural aging (NA) on the natural frequency, damping properties, surface roughness, and geometric tolerances of GCI brake rotors before and after FNC treatment. The GCI brake rotors were subjected to SR and NA processes, followed by FNC treatment. The natural frequency, damping Q-factor, surface roughness, and geometric tolerances were measured and analyzed using two-way ANOVA at a 95% confidence level (α = 0.05). The results showed that SR heat treatment significantly reduced the effect of residual stresses and improved geometric tolerances compared to NA. The FNC treatment increased the surface roughness and slightly improved the damping properties but had an insignificant effect on the natural frequency. The combination of SR and FNC treatments provided the best overall performance in terms of quality, geometric tolerance, and surface finish. This study highlights the importance of SR heat treatment for optimizing the manufacturing process of FNC-treated GCI brake rotors for EVs.

Taxonomic and functional characterization of biofilms from a photovoltaic panel reveals high genetic and metabolic complexity of the communities.

Biofilms are complex microbial cell aggregates that attach to different surfaces in nature, industrial environments, or hospital settings. In photovoltaic panels (PVs), biofilms are related to significant energy conversion losses. In this study, our aim was to characterize the communities of microorganisms and the genes involved in biofilm formation. In this study, biofilm samples collected from a PV system installed in southeastern Brazil were analyzed through shotgun metagenomics, and the microbial communities and genes involved in biofilm formation were investigated. A total of 2030 different genera were identified in the samples, many of which were classified as extremophiles or producers of exopolysaccharides. Bacteria prevailed in the samples (89%), mainly the genera Mucilaginibacter, Microbacterium, Pedobacter, Massilia, and Hymenobacter. The functional annotation revealed >12 000 genes related to biofilm formation and stress response. Genes involved in the iron transport and synthesis of c-di-GMP and c-AMP second messengers were abundant in the samples. The pathways related to these components play a crucial role in biofilm formation and could be promising targets for preventing biofilm formation in the PV. In addition, Raman spectroscopy analysis indicated the presence of hematite, goethite, and ferrite, consistent with the mineralogical composition of the regional soil and metal-resistant bacteria. Taken together, our findings reveal that PV biofilms are a promising source of microorganisms of industrial interest and genes of central importance in regulating biofilm formation and persistence.

Thermal Environments of Residential Areas: Sunlight and Building Shadow in a Chinese City with Hot and Humid Summers

With a primary focus on sunlight and building shadows, we studied the impact of residential building orientation angles, building heights, and area combinations, as well as the underlying surface materials, on the outdoor thermal environment in Changsha, a city located north of the Tropic of Cancer. On the basis of Changsha’s regulations, the research results indicate that building orientation angles of 15–45° and 315–345° can generate more building-shadow areas and have a better effect on improving the outdoor thermal environment. Based on the study of many common residential block building layouts in Changsha, we believe that, for point-pattern residential blocks, an increase in building lengths can be very effective for increasing building-shadow areas and thermal comfort. For row-pattern residential blocks, an increase in building heights can be regarded as more effective for increasing building-shadow areas and reducing air temperatures. Shadow areas formed on impervious surface material areas, such as concrete pavements, reduce the air temperature more than shadow areas formed on natural surfaces, such as grasslands. For the planning and regeneration of residential areas, urban planners should focus on placing more green spaces in areas which are seldom or never covered by building shadows; they should also focus on installing more impervious surfaces in areas covered by building shadows. These strategies are beneficial for making full use of building shadows to reduce air temperatures in residential areas.

Carbon emissions from global impervious surface expansion between 1985 and 2020

Impervious surface expansion (ISE) refers to the phenomenon that natural surfaces are covered by artificial materials, such as cement, asphalt, bricks, etc., usually due to human activities. Over recent decades, the rapid growth of the global population, economic development, and continuous urbanization have contributed to extensive ISE, which caused significant losses in terrestrial ecosystem carbon pools. A global assessment effort is lacking because of limited comprehensive data on carbon pools and uncertainties surrounding the extent of ISE. In this study, we aimed to quantify the carbon emissions resulting from global ISE between 1985 and 2020, following the method provided by the Intergovernmental Panel on Climate Change (IPCC) Guidelines. We first divided global land into 87 fine geographical zones by overlaying continental boundary information with an ecological zone map. Then, multiple time-series impervious surface data products, land cover dynamic monitoring product, global biomass data, and topsoil organic carbon (TSOC) information were integrated to build a lookup table (LUT) of biomass and TSOC density for these fine geographical zones. Last, we employed the IPCC method to estimate carbon emissions from ISE between 1985 and 2020. Our findings indicated a global ISE encompassing a total area of 58.12 Mha, with cropland encroachment accounting for 67.30 %. Over the past 35 years, cumulative committed carbon emissions from global ISE reached 1.14 ± 0.38 PgC, with TSOC representing 54.55 % and biomass carbon contributing 45.45 %.

Fast and efficient remediation of antimony-contaminated surface water and field soil using alumina supported Fe–Mn binary oxide

Antimony (Sb) pollution in surface water and soil has earned extensive attention. Our previous study synthesized a new class of alumina supported Fe–Mn binary oxide (Fe–Mn@Al2O3) and found that MnO2 in the composite oxidized Sb(III) to Sb(V) and FeOOH and Al2O3 played an indispensable role in adsorption of Sb(III) and Sb(V). This study further explored the removal of Sb in surface water and in situ sequestration of Sb in Sb-contaminated field soil via Fe–Mn@Al2O3. Sb removal from water was pH independent and the removal efficiencies of Sb(III) and total Sb kept constant at 95.4% and 60.5%, respectively, over a pH range of 5.0–10.0. Increasing dissolved organic matter (DOM) from 0 to 22.8 mg/L had negligible effect on Sb(III) removal whereas inhibited the total Sb removal from 60.5% to 51.2%. Dissolved oxygen cannot oxidize aqueous Sb(III), yet, enhanced the Sb(III) removal whereas decreased the total Sb removal. The composite performed well in natural surface water with high DOM and inorganic ligands. In addition, the composite effectively immobilized Sb in field soil. 5% of the composite significantly inhibited the H2SO4 and HNO3 leachable Sb by 93.6% after 30 d. The amendment transformed the Sb speciation from more easily available fractions (i.e., exchangeable, carbonate-bound, and Fe–Mn oxides-bound species) into more stable fractions (i.e., organic material bound and residual species), leading to declined Sb bioaccessibility and reduced environmental risk. The composite facilitated a long-term stability of Sb in soil. The study demonstrated an easy, fast, and effective strategy for efficient immobilization of Sb in water and soil.

Effect of SiO2-Li2O3-CuO additive on piezoelectric properties of PMS-PZT ceramics at low sintering temperature

Lead zirconate titanate (PZT) based piezoelectric ceramics are applied in ultrasonic transducers and multilayer actuators fields universally. Excellent piezoelectric properties of PZT-based ceramics of low sintering temperature are crucial for the applications of high-power motors and multilayer piezo-actuators due to the reduction of cost and energy consumption. In this paper, a ternary solid-solution ceramic system 0.05Pb(Mn1/3Sb2/3)O3-0.47PbZrO3-0.48PbTiO3 (PMS-PZT) was studied. A new complex additive composed of SiO2-Li2O3-CuO was doped into the PMS-PZT ceramics. The doping of CuO and Li2O3 was discovered to be able to lower the sintering temperature and remain electric properties efficiently, while the doping of SiO2 can decrease the grain size and increase the density. All ceramic samples were fabricated by solid-phase reaction method and sintered in the low temperature range from 800 °C to 1000 °C. The phase structure, morphology of natural surface and electrical properties of ceramics doped by 0.5 wt% additive were characterized. The 0.5 wt% additive doped PMS-PZT ceramics exhibit remarkable comprehensive piezoelectric properties sintered at 900 °C (d33 = 343 pC/N, Qm = 1016, Tc = 328 °C, tanδ = 0.4 % (at 25 °C), εr = 1344, d33* = 490 pm/V). The sintering temperature 900 °C is significantly below the melting point of Ag (961.9 °C) and Cu (1083.4 °C), so the more cost-effective Cu internal electrodes and Ag rich Ag/Pd electrodes can be used to substitute the expensive Pd rich Ag/Pd internal electrodes in the production of devices composed of multilayer ceramic. The research of this work provides an important candidate additive for the applications of high-performance transducers and multilayer actuators with low cost.

Robust superhydrophobic micro-nanostructures design based on polarity-opposite amorphous polymers

Superhydrophobicity exhibited by several natural surfaces has broad application prospects due to their excellent self-cleaning and low adhesion properties. However, designing a robust superhydrophobic coating via design strategy using amorphous polymers is allimportant for industrial applications, yet rather challenging. Here, we report a scalable strategy based on the phase separation and swelling treatment to construct an ultra-durable superhydrophobic coating with hierarchical micro-/nanostructures formed by two amorphous polymers (e.g. hydrophilic and lipophilic polymers). The controlled phase separation of two amorphous polymers creates uniformly distributed microprotrusions on the coating surface and the following swelling process produces submicro-/nanobumps on the microprotrusions. Notably, when both types of polymers achieve the hierarchical micro-/nanostructures, hydrophilic polymers exhibit strong adhesion with the substrates, whereas lipophilic polymers reduce the surface energy of the system. Benefitting from the self-similar structure and the adhesive effect, the polymer-based superhydrophobic coating displays superior mechanical and chemical robustness. Furthermore, our strategy will boost the practical application of robust superhydrophobic coatings for anti-corrosion application.

Bubble-Guidance Breaking Gas Shield for Highly Efficient Overall Water Splitting.

Overall water splitting is a promising technology for sustainable hydrogen production, but the primary challenge is removing bubbles from the electrode surface quickly to increase hydrogen production. Inspired by the directional fluid transport properties of natural biological surfaces like Nepenthes peristome and Morpho butterfly's wings, here a strategy is demonstrated to achieve highly efficient overall water splitting by a bubble-guidance electrode, that is, an anisotropic groove-micro/nanostructured porous electrode (GMPE). Gradient groove micro/nanostructures on the GMPE serve as high-speed bubble transmission channels and exhibit superior bubble-guidance capabilities. The synergistic effect of the asymmetric Laplace pressure generated between microscale porous structure and groove patterns and the buoyancy along the groove patterns pushes the produced bubbles directionally to spread, transport, and detach from the electrode surface in time. Moreover, the low adhesive nanosheet arrays are beneficial to reduce bubble size and increase bubble release frequency, which cooperatively improve mass transfer with the microscale structure. Notably, GMPE outperforms planar-micro/nanostructured porous electrode (PMPE) in hydrogen/oxygen evolution reactions, with GMPE||GMPE showing better water splitting performance than commercially available RuO2||20 wt.% Pt/C. This work improves electrodes for better mass transfer and kinetics in electrochemical reactions at solid-liquid-gas interfaces, offering insight for designing and preparing gas-involved photoelectrochemical electrodes.

Quantification and analysis study for the morphological characteristics of urban waterbodies: Evidences from 42 cases in China

Influenced by the water design principle of Chinese classical garden, the design of urban waterbodies (lakes, ponds and wetlands) in China typically exhibits natural-like morphological characteristics, but what similarities and differences among these characteristics remain unclear. Also, the morphology of urban waterbodies is mostly designed with beauty and lacks quantitative research and methodological support, which is not favourable to the exploration of the correlation between waterbody morphology and ecology. In this study, 11 quantifiable morphological indicators are selected from water surface, shoreline complexity and water-land spatial morphology. A Grasshopper-based model for waterbody morphology quantification and analysis was constructed and applied to 42 cases in China. Combined with frequency, correlation and PCA analysis, the cases and indicators with higher composite scores generally showed more natural water surface morphology, island distribution, and diversified land and water spaces. The thresholds for the more representative indicators are 0.10–0.60 for the circularity ratio (C), 1.01–1.15 for the shoreline fractal dimension (D0), 1.58–29.42 for the island nearest-neighbour index (NN), 1.20–2.50 for the shoreline development index (SDI), 0.20–0.55 for the compactness ratio (Rc) and 0.30–0.85 for the unit water surface morphological difference ratio (ΔB). Focusing on these indicators, along with ΔB and I which describe spatial inclusiveness and island distribution, their regression equations and threshold ranges provide a primary basis for developing waterbody morphology designs and generative algorithms. This methodology has been experimentally applied in the design of a case waterbody in Suqian City Park. Overall, this study constructs and validates the feasibility of a Grasshopper-based algorithm for the quantitative analysis and morphogenetic design of waterbody morphology. It demonstrates the potential of this method for understanding complex waterbody morphology and water-land spaces, and supports a new digital methodology for the optimisation of waterscape design.

Analysis of Critical Instability Conditions for Solid-Phase Plugging of Natural Fractures during Temporary Plugging and Fracturing.

Hydraulic fracturing has become a key technology for the development of unconventional oil and gas resources, such as deep shale. Due to the development of natural fractures in deep shale reservoirs, the opening of natural fractures during the fracturing process can cause a significant loss of fracturing fluid, resulting in a reduction in the width of the main fracture and construction risks, such as sand plugging. It is important to improve the fracturing effect of deep shale reservoirs by plugging natural fractures with solid phases, reducing filtration, and improving the efficiency of the fracturing fluid. Ensuring the effectiveness of solid plugging is key to optimizing the fracturing design and improving the stimulation effect after fracturing. In this study, solid plugging technology is introduced into the filtration control process of natural fractures. By setting a plugging zone with a certain length and permeability inside the natural fracture, a stability prediction model for the plugging zone of natural fractures is established, and the instability conditions of the plugging zone are analyzed. The simulation results indicate that the instability of the plugging zone is related to permeability and there is a critical permeability. When the permeability of the plugging zone is greater than this value, expansion instability will occur, and when it is less than or equal to this value, shear slip instability may occur. The strength of shear slip instability is mainly determined by the length of the plugging zone, the friction angle of the natural fracture surface, the friction angle between the plugging particles, and the porosity of the plugging zone. The friction angle of natural fracture surfaces affects only the strength of slip instability, while the friction angle of plugging particles and porosity mainly affect the strength of shear instability. The research results provide a theoretical basis for the optimization of fracturing construction parameters in deep shale reservoirs.

Grafting photochromic spiropyran polymer brushes on natural rubber surface via surface-initiated ring-opening metathesis polymerization

The modification of stereoregulated functionalized polymers on the surface of natural rubber (NR) is a challenging task. This work provided a practicable grafting method to design photochromic polymer brushes on the NR surfaces using surface-initiated ring-opening metathesis polymerization (SI-ROMP). The designed photochromic polymer brushes were based on norbornenes with spiropyrin (SP) pendents, and grew from the surface of NR films in the presence of Grubbs 2nd catalyst. The results showed that the grafting rate of polymer brushes with photoisomerization structure reached up to 44.91 %. The modified natural rubber (NR-SP) films exhibited rapid coloring/decolorization property under UV irradiation and visible light. This photochromic property initiated by the light-induced isomerisation of the spiropyran structure and the increased surface energy under light stimuli. NR-SP films exhibited stable photochromic characteristics and outstanding anti-fatigue properties after exposing to over six cycles of consecutive UV/Vis irradiation. A simple and practical strategy for the preparation of highly sensitive photochromic natural rubber materials is proposed and provides a potential application in the fields of information storage and anti-counterfeiting.

Native and TMT Chestnut Extractives as Hydrophobic and Photostabylizing Additives for Wood Surfaces

Wood extractives have proven strong anti-oxidative properties which may be used to mitigate surface deterioration caused by photolytic effects and free radical formations. An interesting challenge regarding wood extractives is understanding how they behave in terms of treating natural wood surfaces to reduce anti-oxidative processes that arise from exposure to the main environmental factors. In this study, the possible efficacy of chestnut (Castanea sativa Mill.) extractives derived from native (CH) and thermally modified wood (TMT CH), as a means of protecting against UV exposure in poplar (Populus spp.) and spruce (Picea abies Karst.) wood, was evaluated. Chestnut wood was first thermally modified at 180 °C for 3 h, and the extractives were obtained by the accelerated solvent extraction technique (ASE) and subsequently used to treat wood surfaces. Samples were immersed in extractive solutions and exposed to artificial UV-weathering exposure, then contact angle and colour stability were monitored during the process. An FTIR analysis of the photo-degradation process of poplar and spruce surfaces was also executed. Extractives of TMT chestnut changed the total colour variation in both poplar and spruce wood. A much darker colour compared to the extractives of native wood was observed and an increase in ∆E* from 9.75 to 30.76 and 6.24 to 22.97 in poplar and spruce was calculated. The stability of the colour depended both on the surface wood and the type of extractive. The initial contact angle remained almost unchanged in the poplar wood surface and only slightly increased in spruce regardless of whether they were treated with extractives from native or TMT chestnut wood. A strong reduction in contact angle after the accelerated UV exposure test was observed, especially in spruce treated with CH extractives. FTIR analysis confirmed the lower levels of chemical degradation of surfaces observed by colorimetry, where TMT CH extractives formed more stable chemical bonds than native extractives. The comparative analysis in this study clarified the complex relationships between the effects of high-temperature modification of wood and the potential protective role of TMT extractives on some wood surfaces.

Effect of sintering temperature on ceramic membrane fabricated using coal flyash and natural clay for lignin recovery

This study explores the utilization of coal fly ash combined with natural clay as a precursor for creating ceramic membranes through the uniaxial compaction method, aiming at lignin separation. These membranes were sintered at varying temperatures from 600 to 1000 °C. Thermal Gravimetric Analysis (TGA) revealed the robust thermal stability of the membranes. Fourier Transform Infrared (FTIR) analysis affirmed the presence of silica and alumina within the membranes. X-ray Diffraction (XRD) peaks indicated the crystalline structure and the presence of metal oxides originating from the fly ash and clay components. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images illustrated the porous nature and rough surface of the ceramic membranes. The average pore radius of the fabricated membrane expanded from 43.12 to 7.91 nm with increasing temperature. Concurrently, membrane flux decreased from 4.13 to 0.96 ×10−6 m3/m2 s with higher temperatures. Lower contact angles indicated the hydrophilic properties of membranes. All membranes exhibited superior corrosion resistance and negative zeta potential, owing to the significant silica content in the fly ash. Lignin separation efficiency increased from 65 % to 81 % with increasing temperatures. The optimal sintering temperature was determined to be 800 °C, achieving a lignin recovery greater than 76 % and a membrane permeability of about 7×10−9 m3/m2 s kPa. Thus, the fly ash-clay-based ultrafiltration membranes synthesized in this study offer the potential for lignin biomass recovery from biorefinery effluent.

Multiple modulating energy-efficient nanofiltration membranes during high-quality drinking water towards high mineral/organic matter selectivity

Solving the low mineral/organic matter selectivity of nanofiltration (NF) membranes and realizing high permeability are effective strategies to satisfy the energy-saving production of high-quality drinking water. Controlling the interfacial polymerization (IP) reaction rate at the molecular level is a feasible approach to customize the functionality of NF membranes and simultaneously modulate multiple membrane properties. Here, we selected 1.4-piperazinediethanesulfonic acid (PIPES) as an aqueous-phase additive, and by taking advantage of the hydrogen-bonding, long-range electrostatic, and steric hindrance effects between PIPES and piperazine (PIP)monomers, as well as the reduction of solution pH, we achieved precise molecular-level regulation of the IP reaction rate. This strategy simultaneously enables the integrated tailoring of various membrane properties such as high hydrophilicity, high surface charge density, uniform pore size distribution and roughness reduction. Molecular dynamics (MD) and computational fluid dynamics (CFD) simulations were used to explore the effects of structural and morphological changes of the polyamide layer on the permeation performance, and the microscopic adsorption mechanism of foulants on the membrane was analyzed by a Quartz Crystal Microbalance (QCM). For pacificating natural surface water, the PIPES-0.75 NF membrane exhibited high permeation performance (23.7 LMH/bar), high mineral/organic selectivity (KCa2+/DOM = 16.5), excellent anti-fouling and anti-scaling properties, and reduced CO2 emissions per ton of water produced up to 90 %. In addition, an attempt was made to correlate the physicochemical properties of the membranes with the permselectivity and membrane fouling, and the economic availability of PIPES-conditioned NF membranes was examined, which provides a novel option for achieving NF in drinking water systems from the perspective of cost reduction and efficiency.

Lower Extremity Injury Rates on Artificial Turf Versus Natural Grass Surfaces in the National Football League During the 2021 and 2022 Seasons.

It has been argued that the use of artificial turf football fields in the National Football League (NFL) increases player injury risk compared with natural grass surfaces. The purpose of this study was to quantify the rate of lower extremity injuries occurring in NFL players on artificial turf compared with natural grass surfaces and characterize the time missed due to injury and proportion of injuries requiring surgery. It was hypothesized that lower extremity injuries requiring surgical intervention would occur at a higher rate on artificial turf than on natural grass. Descriptive epidemiology study. Lower extremity injury data for the 2021 and 2022 NFL seasons were obtained using publicly available records. Data collected included injury type, player position, player age, playing surface, weeks missed due to injury, and whether the patient underwent season-ending or minor surgery. Multivariable logistic regression was performed to determine the risk of season-ending surgery according to playing surface. When combining injuries for the 2021 and 2022 seasons (N = 718 injuries), the incidence rate of lower extremity injury was 1.22 injuries/game for natural grass and 1.42 injuries/game for artificial turf. The odds of a season-ending surgery were found to be significantly higher on artificial turf compared with natural grass (odds ratio = 1.60; 95% CI, 1.28-1.99; P < .05), while additional variables, including weather, age, position, week of injury occurrence, and history of prior injury, did not influence the odds of season-ending surgery. The 2021 and 2022 NFL seasons of our analysis demonstrated a higher incidence rate of injuries on artificial turf surfaces compared with natural grass surfaces. In addition, the odds of injury requiring season-ending surgery were found to be significantly higher on artificial turf compared with natural grass.

Metagenomic insights into ecological risk of antibiotic resistome and mobilome in riverine plastisphere under impact of urbanization

Microplastics (MPs) are of increasing concern due to their role as reservoirs for antibiotic resistance genes (ARGs) and pathogens. To date, few studies have explored the influence of anthropogenic activities on ARGs and mobile genetic elements (MGEs) within various riverine MPs, in comparison to their natural counterparts. Here an in-situ incubation was conducted along heavily anthropogenically-impacted Houxi River to characterize the geographical pattern of antibiotic resistome, mobilome and pathogens inhabiting MPs- and leaf-biofilms. The metagenomics result showed a clear urbanization-driven profile in the distribution of ARGs, MGEs and pathogens, with their abundances sharply increasing 4.77 to 19.90 times from sparsely to densely populated regions. The significant correlation between human fecal marker crAssphage and ARG (R2 = 0.67, P=0.003) indicated the influence of anthropogenic activity on ARG proliferation in plastisphere and natural leaf surfaces. And mantel tests and random forest analysis revealed the impact of 17 socio-environmental factors, e.g., population density, antibiotic concentrations, and pore volume of materials, on the dissemination of ARGs. Partial least squares-path modeling further unveiled that intensifying human activities not only directly boosted ARGs abundance but also exerted a comparable indirect impact on ARGs propagation. Furthermore, the polyvinylchloride plastisphere created a pathogen-friendly habitat, harboring higher abundances of ARGs and MGEs, while polylactic acid are not likely to serve as vectors for pathogens in river, with a lower resistome risk score than that in leaf-biofilms. This study highlights the diverse ecological risks associated with the dissemination of ARGs and pathogens in varied MPs, offering insights for the policymaking of usage and control of plastics within urbanization.