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Objective: We assessed the changes in optical properties and biocompatibility of transition zones in multilayered translucent monolithic zirconia exposed to prolonged hydrothermal aging and compared the results to those with different yttrium oxide contents. Materials and Methods: Four types of zirconia blocks from IPS e.max ZirCAD were used: 3Y-TZP e.max ZirCAD LT (ZL), 4Y-TZP e.max ZirCAD MT (ZM), 5Y-TZP e.max ZirCAD MT Multi (ZT), and 3Y/5Y-TZP e.max ZirCAD Prime (ZP). A total of 120 specimens (15.0 mm diameter and 1.5 mm height) were fabricated and divided into three groups (n = 10). The aging process for the specimens was conducted in an autoclave set to 134 °C and 0.2 MPa, with durations of 0 h (control), 5 h (first aged), and 10 h (second aged). The optical properties and biocompatibility were analyzed, followed by a statistical analysis of the data (α = 0.05). Results: Before and after aging, ZL and ZP exhibited the lowest color changes. ZT exhibited the highest average transmittance and translucency parameter values, while ZL had the lowest. The water contact angle test showed the highest value in ZM and lowest in ZL across all the aging stages. ZL, ZM, and ZP showed a considerable decrease in the water contact angle; however, ZT did not. A cell counting kit-8 assay showed ZL had the highest value, while ZM had the lowest. A filamentous actin test exhibited the highest value in ZL and lowest in ZM. In the vinculin analysis, ZL and ZT exhibited the lowest values, whereas ZM and ZP had the highest. Conclusion: 3Y/5Y-TZP exhibited a balanced performance across critical parameters, such as color stability, translucency, and biocompatibility, aligning with 3Y-TZP. While 5Y-TZP demonstrated superior translucency, it confirmed the lowest color stability, whereas 3Y-TZP achieved the highest biocompatibility. These properties provide clinicians with a reliable material option that ensures superior esthetic outcomes and long-term prognosis, ultimately contributing to improved patient satisfaction and clinical longevity. [ABSTRACT FROM AUTHOR]

This study focuses on the preparation of activated carbon using a petroleum-residue-based pitch, as well as the HCl gas adsorption properties of the resulting activated carbon pellets relative to their specific surface area and pore structure. Activated carbon was prepared under various oxidation and chemical activation conditions using pitch with a softening point of 220 °C. The activated carbon was mixed with distilled water, an acrylic binder, and carboxymethyl cellulose in a specific ratio to form pellets. These pellets were then dried in an oven at 80 °C. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Brunauer–Emmett–Teller analyses were performed to evaluate the surface structure and specific surface area of the finalized pellets. HCl gas was adsorbed at a concentration of 50 ppm while examining the adsorption characteristics relative to the pore structure and specific surface area. [ABSTRACT FROM AUTHOR]

Despite the promising prospects of nanoparticles in oral drug delivery, the process of oral administration involves a complex transportation pathway that includes cellular uptake, intracellular trafficking, and exocytosis by intestinal epithelial cells, which are necessary steps for nanoparticles to enter the bloodstream and exert therapeutic effects. Current researchers have identified several crucial factors that regulate the interaction between nanoparticles and intestinal epithelial cells, including surface properties such as ligand modification, surface charge, hydrophilicity/hydrophobicity, intestinal protein corona formation, as well as holistic properties like particle size, shape, and rigidity. Understanding these properties is essential for enhancing transepithelial transport efficiency and designing effective oral drug delivery systems. Therefore, this review provides a comprehensive overview of the surface and holistic properties that influence the transepithelial transport of nanoparticles, elucidating the underlying principles governing their impact on transepithelial transport. The review also outlines the chosen of parameters to be considered for the subsequent design of oral drug delivery systems. This review summarizes the crucial factors that influence the transepithelial transport of nanoparticles from the perspective of surface and holistic property modulation. [Display omitted] [ABSTRACT FROM AUTHOR]

This study examines the interface of biodegradable polylactic acid (PLA) fiber-reinforced thermoplastic starch composites to address market demand for their mechanical properties. We first used a combination of solution treatment (acid/alkali) and plasma modification to modify fibers. This method improves surface roughness and increases oxygen-containing groups of the fibers, which enhances the mechanical interlocking at the interface and promotes stronger hydrogen bonds between fibers and starch, respectively. Their synergy effect significantly strengthens interfacial adhesion and interfacial shear strength (IFSS). In contrast, cold plasma modification alone results in a smaller increase in IFSS because of its lower roughness and fewer oxygen-containing groups. Alkaline treatment and increased cold plasma power level are more conducive to higher IFSS through stronger synergistic effects. Although IFSS improved from 2.41 to 4.40 MPa after alkali and plasma treatments of 200 W, the tensile strength decreased from 811.46 to 351.55 MPa. To optimize the mechanical properties of composite materials, it is crucial to choose a kind of modification method that balances IFSS enhancement and tensile strength reduction.

Despite the promising prospects of nanoparticles in oral drug delivery, the process of oral administration involves a complex transportation pathway that includes cellular uptake, intracellular trafficking, and exocytosis by intestinal epithelial cells, which are necessary steps for nanoparticles to enter the bloodstream and exert therapeutic effects. Current researchers have identified several crucial factors that regulate the interaction between nanoparticles and intestinal epithelial cells, including surface properties such as ligand modification, surface charge, hydrophilicity/hydrophobicity, intestinal protein corona formation, as well as holistic properties like particle size, shape, and rigidity. Understanding these properties is essential for enhancing transepithelial transport efficiency and designing effective oral drug delivery systems. Therefore, this review provides a comprehensive overview of the surface and holistic properties that influence the transepithelial transport of nanoparticles, elucidating the underlying principles governing their impact on transepithelial transport. The review also outlines the chosen of parameters to be considered for the subsequent design of oral drug delivery systems.

Abstract Acrylic resins are widely used as the main components in removable orthodontic appliances. However, poor oral hygiene and maintenance of orthodontic appliances provide a suitable environment for the growth of pathogenic microorganisms. In this study, strontium-modified phosphate-based glass (Sr-PBG) was added to orthodontic acrylic resin at 0% (control), 3.75%, 7.5%, and 15% by weight to evaluate the surface and physicochemical properties of the novel material and its in vitro antifungal effect against Candida albicans (C. albicans). Surface microhardness and contact angle did not vary between the control and 3.75% Sr-PBG groups (p > 0.05), and the flexural strength was lower in the experimental groups than in the control group (p 0.05). All experimental groups showed an antifungal effect at 24 and 48 h compared to that in the control group (p

In this research, a straightforward template method was utilized to fabricate a superhydrophilic ethylene-vinyl acetate copolymer (EVA)/nitrile-butadiene rubber (NBR) thermoplastic vulcanizate (TPV) surface where the paper sheet was used as template. Organic modified montmorillonite (OMMT) powder was introduced in order to improve the superhydrophilic response rate of the TPV surface. Investigations were conducted to research the durability and the self-cleaning behavior of the TPV surface, as well as to explore its potential application in the separation of oil-water and oil-oil mixtures. Experimental results demonstrated that the EVA/NBR/OMMT TPV (mass ratio 20/80/7) surface molded with No. 1000 paper sheet exhibited the excellent superhydrophilic property, which could achieve a contact angle of 0.0° within 5.5 s and had a surface energy of 35.6 mN·m–1. The superhydrophilic surface displayed the remarkable durability and the evident self-cleaning behavior; moreover, it could exhibit the significant difference in the critical pressure data for various liquids, suggesting the promising application in the field of oil-water and oil-oil separation.

Improving the durability of short-rotation wood can be achieved through chemical and thermal modification. Chemical and thermal modification can have an impact on the physicochemical properties of wood, which can affect wood's surface characteristics and its resistance to weathering. The purpose of this study was to investigate the surface characteristics and artificial weathering resistance of chemically and thermally modified short-rotation teak wood coated with linseed oil (LO)-, tung oil (TO)-, and commercial oil-based coatings consisting of a mixture of linseed oil and tung oil (LT) and commercial oil-based polyurethane resin (LB) coatings. The short-rotation teak woods were prepared in untreated and treated with furfuryl alcohol (FA), thermal treatment (HT) at 150 and 220 °C, and combination of glycerol–maleic anhydride (GMA) impregnation with thermal treatment at 150 and 220 °C. The surface characteristics measured were surface free energy, wettability, Persoz hardness, bonding quality, and color changes before and after artificial weathering exposure. The results showed that chemical and thermal modifications treatment tended to reduce total surface free energy (SFE), hardness, wettability, and bonding quality. FA and GMA at 220 °C treatments provided homogenization effect on surface characteristics, especially in total SFE and wettability. The total SFE of untreated wood ranged from 45.00 to 51.13 mN/m, and treated wood ranged from 40.58 to 50.79 mN/m. The wettability of oil-based coating according to K-value ranged from 0.20 to 0.54. TO presented better photostability than LO. Short-rotation teak wood coated with oil-based commercial coatings presented better weathering resistance compared to pure natural drying oil. Commercial oil-based coatings provided better weathering protection for the chemically and thermally modified teak wood. The application of oil-based coatings on chemically and thermally modified short-rotation teak is being considered for the development of a better wood-protection system. [ABSTRACT FROM AUTHOR]

Cerussite is an essential lead oxide mineral with increasing economic importance as lead sulfide resources deplete. This study utilizes density functional theory (DFT) to investigate the structural and electronic properties of the sulfurized cerussite (110) surface. The results show that when the cerussite crystal cleaves along the (110) plane, only the surface layer atoms undergo relaxation to reconstruct the surface, while the atoms located deeper have almost no impact on the reconstructed surface structure. The Pb atoms on the cerussite (110) surface react with the sulfurizing agent to form a PbS deposition layer with a structure similar to galena. This PbS deposition layer is tightly adsorbed onto the lead oxide layer through Pb-S bonds formed by S and subsurface lead oxide structure Pb atoms. The chemical reactivity of Pb atoms in the PbS layer on the sulfurized cerussite (110) surface is more potent than that of Pb atoms on the galena surface; additionally, the Pb atoms closer to the lead oxide layer exhibit slightly higher chemical reactivity than those farther away. This study provides insight into sulfurized cerussite surfaces' structure and properties at an atomic level and assists in explaining the floating behavior of cerussite. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the surface properties and bacterial adhesion of computer-aided design-computer-aided manufacturing (CADCAM) restorative materials. Methods: Four CAD-CAM resin-based blocks (Vita Enamic, Shofu block HC, Cerasmart [CS] and Lava Ultimate [LU]) and a leucite-reinforced glass ceramic block (IPS Empress CAD) were used in the present study. Specimens prepared with dimensions of 10 × 10 × 1 mm were polished. Surface characteristics were assessed with hydrophobicity and surface free energy (SFE) analysis. Surface roughness was measured using a profilometer, and elemental and topographic evaluations were performed with SEM-EDX analysis. After being kept in artificial saliva for 1 h, Streptococcus mutans (S. mutans) and Streptococcus mitis (S. mitis) were incubated separately in 5% CO2 atmosphere at 37°C for 24 h. The adhered bacteria were counted as ×108 CFU/mL. Results: Surface roughness, contact angle and SFE measurement values were found to be in the range of 0.144-0.264 Ra, 28.362°-70.074° and 39.65-63.62 mN/m, respectively. The highest adhered amount of S. mutans was found in CS and the lowest in LU, while there was no significant difference between the amounts of adhered S. mitis. Conclusion: Despite differences in the surface properties of the materials used for the study, the materials exhibited identical properties with respect to bacterial adhesion. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Twitching motility is a form of bacterial surface translocation powered by the type IV pilus (T4P). It is frequently analyzed by interstitial colony expansion between agar and the polystyrene surfaces of petri dishes. In such assays, the twitching motility of Acinetobacter nosocomialis was observed with MacConkey but not Luria-Bertani (LB) agar media. One difference between these two media is the presence of bile salts as a selective agent in MacConkey but not in LB. Here, we demonstrate that the addition of bile salts to LB allowed A. nosocomialis to display twitching. Similarly, bile salts enhanced the twitching of Acinetobacter baumannii and Pseudomonas aeruginosa in LB. These observations suggest that there is a common mechanism, whereby bile salts enhance bacterial twitching and promote interstitial colony expansion. Bile salts disrupt lipid membranes and apply envelope stress as detergents. Surprisingly, their stimulatory effect on twitching appears not to be related to a bacterial physiological response to stressors. Rather, it is due to their ability to alter the physicochemical properties of a twitching surface. We observed that while other detergents promoted twitching like bile salts, stresses applied by antibiotics, including the outer membrane-targeting polymyxin B, did not enhance twitching motility. More importantly, bacteria displayed increased twitching on hydrophilic surfaces such as those of glass and tissue culture-treated polystyrene plastics, and bile salts no longer stimulated twitching on these surfaces. Together, our results show that altering the hydrophilicity of a twitching surface significantly impacts T4P functionality.IMPORTANCEThe bacterial type IV pilus (T4P) is a critical virulence factor for many medically important pathogens, some of which are prioritized by the World Health Organization for their high levels of antibiotic resistance. The T4P is known to propel bacterial twitching motility, the analysis of which provides a convenient assay for T4P functionality. Here, we show that bile salts and other detergents augment the twitching of multiple bacterial pathogens. We identified the underlying mechanism as the alteration of surface hydrophilicity by detergents. Consequently, hydrophilic surfaces like those of glass or plasma-treated polystyrene promote bacterial twitching, bypassing the requirement for detergents. The implication is that surface properties, such as those of tissues and medical implants, significantly impact the functionality of bacterial T4P as a virulence determinant. This offers valuable insights for developing countermeasures against the colonization and infection by bacterial pathogens of critical importance to human health on a global scale.

To investigate the influence and mechanism of different surface pretreatment methods on the surface properties of oriented organic glass and its bonding strength with thermoplastic polyurethane (TPU). AFM, FTIR, and contact angle measuring instruments were used to measure the surface chemical composition, roughness, and surface contact angle of oriented organic glass after acid treatment, plasma treatment, and transition layer treatment.The bonding strengths between oriented organic glass and TPU before and after pretreatment were tested by using a 90 ° peel test. The results show that the surface roughness and polarity of oriented organic glass increase after acid treatment and plasma treatment, and the surface wettability is improved, resulting in 14% and 22% increase in bonding strength, respectively. The pre-treatment of the transition layer improves the chemical compatibility between the substrate and TPU. After treatment, the surface polarity of the oriented organic glass is similar to that of TPU, reducing the interfacial tension, and improving the interfacial bonding performance significantly. The bonding strength increases from 4.44 kN/m to 23.61 kN/m.

Using the self-association model, the effect of temperature on the segregation tendency in the bulk and surface of liquid Ga-Tl alloys was investigated. The ratio of the numbers of two types of atoms in the cluster (n) and the interchange energy (W) in the self-association model were two crucial factors, but it was unknown how these values changed with temperature, which limited the model's capacity for prediction. The current investigation revealed that the exchange energy was linearly related to temperature and that the ratio of the two types of atoms in the cluster was temperature-independent, which was verified by the good agreement of the predicted thermophysical properties, miscibility gap, and surface properties with the available experimental data. This work enhances the theoretical explanation of the self-association model and provides a straightforward method for forecasting liquid immiscible alloys across a wide temperature spectrum. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Bifunctional Cu-CuBr substrate was first constructed by electrochemical methods. • It exhibits high sensitivity and excellent stability (more than 1 year) • MOFs improve SERS and catalytic performance by changing surface properties. • In-situ SERS monitoring of the photocatalytic dehalogenation reaction process. • In-situ SERS reveals the role of MOFs on photocatalytic selectivity. Photocatalytic reactions using copper-based nanomaterials have emerged as a new paradigm in green technology. Selective photocatalysis is very important for improving energy utilization efficiency, and in order to directional improve catalytic selectivity, it is necessary to understand the mechanism of interfacial reactions at the molecular level. Therefore, a unique bifunctional Cu-CuBr substrate is first fabricated via an electrochemical method, which overcomes the instability of traditional copper-based materials and endows high surface-enhanced Raman spectroscopy (SERS) sensitivity and photocatalytic performance and can be stored stably for more than a year. Further modification of the surface with Metal-Organic Frameworks (MOFs) containing carboxyl functional groups can significantly tune the surface properties of the substrate. This increases the adsorption of cationic dyes to improve the SERS effect, and 10−10 M methylene blue can easily be detected with this substrate. Surprisingly, in-situ SERS monitoring of the interfacial photocatalytic dehalogenation reaction of aromatic halides through its intrinsic SERS effect reveal two competing selective reaction pathways, self-coupling and hydrogenation. Typically, the SERS spectra reveal that the latter's selectivity was greatly enhanced after MOFs modification, and the yield rate of the hydrogenated product increased from 27.6 % to 46.9 % (selectivity increased from 32.7 % to 51.5 %). This proves that the surface properties of catalysts, especially the affinity for reaction intermediates, can effectively regulate catalytic selectivity. [ABSTRACT FROM AUTHOR]

Current transition alumina catalysts require the presence of significant amounts of toxic, environmentally deleterious dopants for their stabilization. Herein, we report a simple and novel strategy to engineer transition aluminas to withstand aging temperatures up to 1200 °C without inducing the transformation to low‐surface‐area α‐Al2O3 and without requiring dopants. By judiciously optimizing the abundance of dominant facets and the interparticle distance, we can control the temperature of the phase transformation from θ‐Al2O3 to α‐Al2O3 and the specific surface sites on the latter. These specific surface sites provide favorable interactions with supported metal catalysts, leading to improved metal dispersion and greatly enhanced catalytic activity for hydrocarbon oxidation. The results presented herein not only provide molecular‐level insights into the critical factors causing deactivation and phase transformation of aluminas but also pave the way for the development of catalysts with improved activity for catalytic hydrocarbon oxidation. [ABSTRACT FROM AUTHOR]

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to investigate the effect of surface properties of nanoparticles (NPs) on the crystallization behavior of nanocomposite, three kinds of silica (SiO2) NPs are dispersed in isotactic polypropylene (iPP) matrix by solution blending method. Specifically, the poor compatibility between inorganic bare SiO2 NPs and organic PP matrix triggers the formation of aggregates and induces the fractionated crystallization with two crystallization peaks at higher particle loading (Φ), i.e., main crystallization peak (MCP) and low temperature crystallization peak (LCP, always located at 124.0 °C). Once short PP chains (0.9 × 104 g mol−1) are grafted onto the surface of SiO2 NPs, the nanocomposites with all Φ only exhibit a single MCP which is attributed to the strong interfacial interaction. With the increase of grafting chain length (9 × 104 g mol−1), the more stretched conformation of grafting chains can provide numerous heterogeneous nucleation sites and significantly accelerate the crystallization rate of PP chains near the surface of SiO2 NPs, which lead to the formation of an extra high temperature crystallization peak (HCP, almost kept constant at 133.0 °C). The occurrence of various crystallization peaks implies that the surface properties of nanoparticles play a vital role in the nucleation ability of nanoparticles. [ABSTRACT FROM AUTHOR]

The increase in environmental consciousness and waste-to-wealth concepts in the automobile sector has led to the use of natural fibers in desirable quantities. The current study deals with the extraction, treatment, and utilization of Lycium ferocissimum stem fibers for friction composite in braking applications. The fibers of Lycium ferocissimum were extracted through manual retting and subsequently treated with benzoyl chloride. Both the benzoyl chloride treated and untreated fibers of Lycium ferocissimum were employed as reinforcements in the formulation of a friction composite, following the standard practices of the industry, and the comparison was made using commercially available friction composite. The developed friction composites were tested for original equipment manufacturer quality requirements following industrial Standards. The friction composite’s tribological behavior was analyzed using the Chase test following the Society of Automotive Engineers standards. The worn surface characteristics were analyzed using scanning electron microscope. The test results elucidated that benzoyl chloride-treated Lycium ferocissimum fibers-based friction composites showed good frictional properties with better wear resistance compared to others, having a weight loss of 5.4%.

Objective: We assessed the changes in optical properties and biocompatibility of transition zones in multilayered translucent monolithic zirconia exposed to prolonged hydrothermal aging and compared the results to those with different yttrium oxide contents. Materials and Methods: Four types of zirconia blocks from IPS e.max ZirCAD were used: 3Y-TZP e.max ZirCAD LT (ZL), 4Y-TZP e.max ZirCAD MT (ZM), 5Y-TZP e.max ZirCAD MT Multi (ZT), and 3Y/5Y-TZP e.max ZirCAD Prime (ZP). A total of 120 specimens (15.0 mm diameter and 1.5 mm height) were fabricated and divided into three groups (n = 10). The aging process for the specimens was conducted in an autoclave set to 134 °C and 0.2 MPa, with durations of 0 h (control), 5 h (first aged), and 10 h (second aged). The optical properties and biocompatibility were analyzed, followed by a statistical analysis of the data (α = 0.05). Results: Before and after aging, ZL and ZP exhibited the lowest color changes. ZT exhibited the highest average transmittance and translucency parameter values, while ZL had the lowest. The water contact angle test showed the highest value in ZM and lowest in ZL across all the aging stages. ZL, ZM, and ZP showed a considerable decrease in the water contact angle; however, ZT did not. A cell counting kit-8 assay showed ZL had the highest value, while ZM had the lowest. A filamentous actin test exhibited the highest value in ZL and lowest in ZM. In the vinculin analysis, ZL and ZT exhibited the lowest values, whereas ZM and ZP had the highest. Conclusion: 3Y/5Y-TZP exhibited a balanced performance across critical parameters, such as color stability, translucency, and biocompatibility, aligning with 3Y-TZP. While 5Y-TZP demonstrated superior translucency, it confirmed the lowest color stability, whereas 3Y-TZP achieved the highest biocompatibility. These properties provide clinicians with a reliable material option that ensures superior esthetic outcomes and long-term prognosis, ultimately contributing to improved patient satisfaction and clinical longevity.

This study focuses on the preparation of activated carbon using a petroleum-residue-based pitch, as well as the HCl gas adsorption properties of the resulting activated carbon pellets relative to their specific surface area and pore structure. Activated carbon was prepared under various oxidation and chemical activation conditions using pitch with a softening point of 220 °C. The activated carbon was mixed with distilled water, an acrylic binder, and carboxymethyl cellulose in a specific ratio to form pellets. These pellets were then dried in an oven at 80 °C. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Brunauer–Emmett–Teller analyses were performed to evaluate the surface structure and specific surface area of the finalized pellets. HCl gas was adsorbed at a concentration of 50 ppm while examining the adsorption characteristics relative to the pore structure and specific surface area.

The need for lithium in energy storage systems has risen dramatically due to the development of renewable energy technology, portable devices, and electric cars. The current review focuses on the existing worldwide resources of lithium ore, along with the production, demand, and mineralogy of lithium-bearing minerals, in addition to lithium recovery from hard pegmatite ore using different beneficiation techniques. Lithium ore is beneficiated using various methods, including magnetic separation, gravity concentration, electrostatic separation, and flotation to separate gangue minerals. Flotation is the most frequently utilized beneficiation technique. It is found that gravity concentration and flotation are the main beneficiation methods used in many plants around the world. In flotation, reagent chemistry, surface properties, and water quality were critical in spodumene's efficient recovery. A summary of several reagent regimes, surface properties, flotation conditions, and prospective future studies for technical viability are provided. The current review paper also discusses the beneficiation flowsheet widely used to recover spodumene, lepidolite, and petalite from pegmatite ore. Also, it is tried to discuss the key future research areas along with the cost economics aspect of processing such ore deposits to recover lithium. [ABSTRACT FROM AUTHOR]

The variation of particle properties and surface physicochemical properties during coal crushing was studied. The geometric properties of coal particles were explored by analyzing the particle size distribution curve under the dual-domain fractal rule and the surface morphology under the scanning electron microscope. With the increased refinement degree, the fine particle size gradually concentrated and uniform, and the population difference of coarse particle size increased. The dominant force for particle refinement transitioned from shear force to crushing force, and the angular coal particles gradually had roundness and aggregation of ultrafine particles appeared. The surface properties of the particles were analyzed by the surface pore structure, the surface functional group content and the charge state. The specific surface area and average pore size of the coal particles gradually increased, and the adsorption kinetic constant gradually decreased, indicating that the crushing exposed the new surface and made the micro pores more developed. The oxygen-containing functional groups on the surface gradually decreased and the isoelectric point gradually increased, indicating that the hydrophobicity of the particles decreased gradually during the refinement process. [ABSTRACT FROM AUTHOR]

Cerussite is an essential lead oxide mineral with increasing economic importance as lead sulfide resources deplete. This study utilizes density functional theory (DFT) to investigate the structural and electronic properties of the sulfurized cerussite (110) surface. The results show that when the cerussite crystal cleaves along the (110) plane, only the surface layer atoms undergo relaxation to reconstruct the surface, while the atoms located deeper have almost no impact on the reconstructed surface structure. The Pb atoms on the cerussite (110) surface react with the sulfurizing agent to form a PbS deposition layer with a structure similar to galena. This PbS deposition layer is tightly adsorbed onto the lead oxide layer through Pb-S bonds formed by S and subsurface lead oxide structure Pb atoms. The chemical reactivity of Pb atoms in the PbS layer on the sulfurized cerussite (110) surface is more potent than that of Pb atoms on the galena surface; additionally, the Pb atoms closer to the lead oxide layer exhibit slightly higher chemical reactivity than those farther away. This study provides insight into sulfurized cerussite surfaces’ structure and properties at an atomic level and assists in explaining the floating behavior of cerussite.

Improving the durability of short-rotation wood can be achieved through chemical and thermal modification. Chemical and thermal modification can have an impact on the physicochemical properties of wood, which can affect wood’s surface characteristics and its resistance to weathering. The purpose of this study was to investigate the surface characteristics and artificial weathering resistance of chemically and thermally modified short-rotation teak wood coated with linseed oil (LO)-, tung oil (TO)-, and commercial oil-based coatings consisting of a mixture of linseed oil and tung oil (LT) and commercial oil-based polyurethane resin (LB) coatings. The short-rotation teak woods were prepared in untreated and treated with furfuryl alcohol (FA), thermal treatment (HT) at 150 and 220 °C, and combination of glycerol–maleic anhydride (GMA) impregnation with thermal treatment at 150 and 220 °C. The surface characteristics measured were surface free energy, wettability, Persoz hardness, bonding quality, and color changes before and after artificial weathering exposure. The results showed that chemical and thermal modifications treatment tended to reduce total surface free energy (SFE), hardness, wettability, and bonding quality. FA and GMA at 220 °C treatments provided homogenization effect on surface characteristics, especially in total SFE and wettability. The total SFE of untreated wood ranged from 45.00 to 51.13 mN/m, and treated wood ranged from 40.58 to 50.79 mN/m. The wettability of oil-based coating according to K-value ranged from 0.20 to 0.54. TO presented better photostability than LO. Short-rotation teak wood coated with oil-based commercial coatings presented better weathering resistance compared to pure natural drying oil. Commercial oil-based coatings provided better weathering protection for the chemically and thermally modified teak wood. The application of oil-based coatings on chemically and thermally modified short-rotation teak is being considered for the development of a better wood-protection system.

The product quality problem of high Al steel is closely related to the agglomeration behavior of inclusions. The present study firstly established the stability diagram of inclusion in the Fe–Al–O–N system, thereby evaluating the formation behavior and control condition of various inclusions can be obtained. Based on that, laboratory-scale experiments with different Al contents were designed to obtain the inclusion evolution process. Furthermore, the calculated agglomeration forces were used to explain the difference of evolution of various inclusions. The cavity bridge force increases with the increase of diameter of inclusions and decrease of distance between inclusions, and the van deer Waals force decreases with the increase of diameter and distance. Due to the cavity bridge force is larger than van deer Waals force, the inclusions firstly approached each other by van deer Waals force and then agglomerated by cavity bridge force. In addition, the cavity bridge force of Al2O3 is larger than that of AlN at the same condition because of the larger contact angle. However, the increase of Al content makes this phenomenon converse. When the Al content is > 3 wt. %, the cavity bridge force of AlN is larger than that of Al2O3. When the Al content is > 7 wt. %, the cavity bridge force of Al2O3 disappears. The study can provide theoretical support for inclusion control in high Al steel.

The rapid repair capability of damaged pavement is an important factor that restricts the generation of air force combat effectiveness in wartime, and the testing technology in the process of emergency repair is an important aspect to reflect the capability, but the current testing technologies cannot meet the use requirements. Based on theoretical analysis and testing practice, the test technologies of committed step in airport pavement emergency repair, such as determination of repair scope, testing of structural bearing capacity and pavement surface characteristics, are compared and analyzed in this study, and suggestions for future development are put forward. The results show that the methods of visual inspection, laser level gauge and laser sweeper still have some problems, such as cumbersome testing process, large possibility of error, and inability to quickly and accurately determine the elevation deviation. The better method is to customize the laser with clear light within 15 meters under strong light, and integrate the laser rangefinder; the heavy weight deflectometer and aircraft load simulation loading vehicle method are are suitable for verifying the final bearing capacity in peacetime research, and are not suitable for testing during wartime rush repair. The dynamic cone penetrometer method has shortcomings such as insufficient simplicity in the testing process and the need for further calculation. The better method is to use the light weight deflectometer to test the dynamic deformation modulus as an evaluation index. The friction coefficient test car method and the laser flatness instrument method are not suitable for emergency repair pavement testing. The portable pendulum tester method and the three-meter ruler method can be used for small-scale repair road surface performance testing. A better method is to develop a joint test method for skid resistance and flatness based on smart phones. The research results can provide technical supports for improving the efficiency of airport pavement repair. [ABSTRACT FROM AUTHOR]

1-O-alkylglycerols are a class of natural existing lipids with broad biological activities. However, their use in food or agricultural fields remains to be investigated, especially for their antimicrobial activity. In this work, three 1-O-alkylglycerols, 1-O-octanylglycerol (C8Gly1), 1-O-dodecylglycerol (C12Gly1), and 1-O-hexadecylglycerol (C16Gly1), were synthesized in the isolated yields of 71.3–89.8 % and characterized by 1H NMR, 13C NMR, FITR, mass spectra, and HPLC-ESLD. The critical micelle concentration (CMC) of 1-O-alkylglycerols was determined to be 1.65 mmol/L (C8Gly1), 0.33 mmol/L (C12Gly1), and 0.23 mmol/L (C16Gly1) using the pyrene method. C12Gly1 and C16Gly1 had similar surface tensions that are lower than C8Gly1. C8Gly1 can form micelles in aqueous solution with excellent nano-dispersed uniformity and stability. Furthermore, C8Gly1 and C12Gly1 not only displayed good antibacterial activity against Staphylococcus aureus, but they also inhibited the growth of Botryosphaeria dothidea, Monilia fructigena, and Phytophthora capsicum at 400 μg/mL. Thus, the C8Gly1 and C12Gly1 can serve as novel antimicrobial agents in food preservation.

Interventional catheter is the essential assembly part of interventional therapy. Confronted with complex channels, the catheter suffers from weak mechanical property, high catheter-tissue friction and inferior biocompatibility. Herein, the robust mechanical, lubricated and biocompatible molybdenum disulfide (MoS2)/polypropylene (PPR) catheter was fabricated via flow-directed preferential alignment and fluorination treatment. By rotating the mandrel and die, a dual-directional flow field was constructed and the two-dimensional MoS2 plates aligned preferentially with the planar surface perpendicular to the radial direction of the catheter. Benefiting from the preferential alignment of MoS2 plates, the tensile strength of the rotationally-extruded MoS2/PPR catheter increased by 25.1% compared to the pristine PPR catheter. Furthermore, the direct fluorination treatment was applied to endow the optimized tribology performance and biocompatibility. As a result, the MoS2/PPR catheter with excellent comprehensive performance was prepared by bulk morphology and surface manipulation strategy, which was suitable for industrial scale preparation.

A comprehensive comparison of the trends and drivers of global surface and canopy urban heat islands (termed Is and Ic trends, respectively) is critical for better designing urban heat mitigation strategies. However, such a global comparison remains largely absent. Using spatially continuous land surface temperatures and surface air temperatures (2003–2020), here we find that the magnitude of the global mean Is trend (0.19 ± 0.006°C/decade, mean ± SE) for 5,643 cities worldwide is nearly six‐times the corresponding Ic trend (0.03 ± 0.002°C/decade) during the day, while the former (0.06 ± 0.004°C/decade) is double the latter (0.03 ± 0.002°C/decade) at night. Variable importance scores indicate that global daytime Is trend is slightly more controlled by surface property, while background climate plays a more dominant role in regulating global daytime Ic trend. At night, both global Is and Ic trends are mainly controlled by background climate. Plain Language Summary: Surface and canopy urban heat islands (surface and canopy UHIs, termed Is and Ic) are two major UHI types. These two counterparts are both related to urban population heat exposure and have long been a focus of urban climate research. However, the differences in the trends and major determinants of Is and Ic over global cities remain largely unclear. Based on spatially continuous land surface temperature and surface air temperature observations from 2003 to 2020, we find that the global mean Is trends are about 6.3 times and 2 times the Ic trends during the day and at night, respectively. During the day, the global Is trend is more regulated by surface property than by background climate, and vice versa for global Ic trend. At night, both the global Is and Ic trends are mainly regulated by background climate. These findings are important for better understanding global urban climate change and informing heat mitigation strategies. Key Points: The global Is trend is six‐fold and twofold larger than the Ic trend during the day and at night, respectivelyDuring the day, global Is trend is slightly more controlled by surface property, yet background climate plays a dominant role in Ic trendAt night, both global Is and Ic trends are more regulated by background climate [ABSTRACT FROM AUTHOR]

Poplars and their hybrids are widely planted in both plantation forestry and agroforestry systems of the world. Along with the utilization and plantation management processes, a large amount of biomass residues are produced, but the relationship between biochar properties and soil CO2 emissions is largely unknown. Here, a laboratory incubation study was conducted to assess the effects of different biochars and their corresponding biomass residues on soil CO2 emissions during the 180 days of incubation. Poplar residue‐derived biochars were larger in the surface area and total pore volume but lower in nutrients and pH values than the rice straw‐derived biochar. Increasing pyrolysis temperature led to a decrease in the total nitrogen (TN) content of poplar leaf‐ and rice straw‐derived biochars, but enhanced the TN in the poplar twig‐ and poplar bark‐derived biochars. After 180‐day incubation, the total cumulative CO2 emission decreased by 33.1%–73.8% in the biochar amendments compared to their corresponding biomass residue addition, whereas the biochars derived from poplar twig and bark residues had more positive effects on reducing soil CO2 emissions, but depended on the pyrolysis temperature. Correlation analysis showed a significant and positive correlation between the CO2 emissions and TN content of bio‐based materials but the negative relationships to total carbon content and C/N ratio. Meanwhile the positive correlations of CO2 emissions to the surface area, t‐plot micropore area, and volume of the biochars were detected. Our results suggest that application of poplar twig‐ and poplar bark‐derived biochars has a great potential for mitigating global warming. [ABSTRACT FROM AUTHOR]

To improve surface properties of poly(methyl methacrylate) (PMMA) using nano‐ceramic coatings and assess microbial adherence after long‐term use of a chemical cleanser. Thirty‐six PMMA samples were fabricated, polished and coated with a nano‐thin TiO2 or mixed TiO2/ZrO2, with uncoated samples as controls. Six samples in each group (n = 12) were soaked in Polident denture cleaner 180 times for 30 min, while six were soaked in deionized water. Surface roughness of PMMA before and after being soaked in Polident was assessed. All samples were subsequently exposed to Candida albicans for 6 h and the adherent cells were determined by viable colony count. Two‐way analysis of variance was performed for statistical analysis. No significant difference in surface roughness was noted between the uncoated and coated PMMA before soaking. After soaking, surface roughness of the uncoated PMMA increased from 0.164 to 0.532 μm (p <.05). No significant change was observed for TiO2‐coated (0.105–0.143 μm) or TiO2/ZrO2‐coated PMMA (0.104–0.141 μm). Attachment of C. albicans to PMMA soaked in water showed significantly less attachment to both TiO2‐coated (1.4 × 103 cfu/ml) and TiO2/ZrO2‐coated PMMA (1.6 × 103 cfu/ml) than to the uncoated PMMA (2.6 × 103 cfu/ml). After soaking in Polident, the uncoated PMMA had significantly less C. albicans attachment than coated samples. Less attachment was noted on the TiO2/ZrO2‐coated PMMA then the TiO2‐coated samples (p <.05). Nano‐ceramic TiO22/ZrO2 coating of PMMA denture base material alters surface properties thus reduces oral microbial adhesion. It represents a promising alternative to the chemical disinfection for PMMA denture materials. [ABSTRACT FROM AUTHOR]

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In the present study, surface properties of three types of carbon fibers (CCF300, CCM40J, and CCF800H) on the interface properties of carbon fiber/epoxy resin (CF/EP) were analyzed. The composites are further modified by graphene oxide (GO) to obtain GO/CF/EP hybrid composites. Meanwhile, the effect of the surface properties of CFs and the additive graphene oxide on the interlaminar shear properties and dynamic thermomechanical properties of GO/CF/EP hybrid composites are also analyzed. The results show that the higher surface oxygen-carbon ratio of carbon fiber (CCF300) has a positive effect on improving the glass transition temperature (Tg) of the CF/EP composites. The Tg of CCF300/EP is 184.4 °C, while the Tg of CCM40J/EP and CCF800/EP are only 177.1 °C and 177.4 °C, respectively. Furthermore, deeper and more dense grooves on the fiber surface (CCF800H and CCM40J) are more conducive to improving the interlaminar shear performance of the CF/EP composites. The interlaminar shear strength (ILSS) of CCF300/EP is 59.7 MPa, and that of CCM40J/EP and CCF800H/EP are 80.1 MPa and 83.5 MPa, respectively. For the GO/CF/EP hybrid composites, graphene oxide with abundant oxygen-containing groups is beneficial to improve the interfacial interaction. Graphene oxide can significantly improve the glass transition temperature and interlamellar shear strength of GO/CCF300/EP composites fabricated by CCF300 with a higher surface oxygen-carbon ratio. For the CCM40J and CCF800H with lower surface oxygen-carbon ratio, graphene oxide has a better modification effect on the glass transition temperature and interlamellar shear strength of GO/CCM40J/EP composites fabricated by CCM40J with deeper and finer surface grooves. Regardless of the type of carbon fiber, the GO/CF/EP hybrid composites with 0.1% graphene oxide have the optimized interlaminar shear strength, and the GO/CF/EP hybrid composites with 0.5% graphene oxide have the maximum glass transition temperature. [ABSTRACT FROM AUTHOR]

Waste sludge produced from wastewater treatment has been regarded as a potential reservoir of microplastics. In order to investigate the effect of sludge microbial decomposition on the microplastics, polypropylene, polyethylene, polyvinyl chloride, and tire microplastics are chosen to investigate changes in their surface properties during anaerobic sludge treatment process. The results show that the intensity of oxygen-containing functional groups such as carbonyl and hydroxyl exhibits an increasing tread with anaerobic sludge microbial treatment time, indicating an enhanced hydrophilicity of microplastic surface, which is further confirmed by contact angle results. Correlation results show that carbonyl index can favorably reflect the impact of anaerobic sludge microorganisms on the surface properties of polyethylene and polyvinyl chloride microplastics, while the surface changes of polypropylene and styrene butadiene rubber tire microplastics can be characterized with the absorption peak areas in wavenumber range of 1 300 to 1 500 cm-1. This study can provide theoretical basis for further investigating the sludge microorganism-driven decomposition and reaction behavior of microplastics. [ABSTRACT FROM AUTHOR]

Abstract Background The roughening of the inner surface of a fixed ceramic restoration is an important factor for the bonding process. The aim of this study is to investigate the effect of combined surface treatments (acid etching, air-abrasion and Er: YAG Laser) on surface roughness of CAD/CAM fabricated zirconia (ZrO2) and lithium-disilicate glass ceramics (LDS). Methods Sixty ZrO2 (Ceramill Zi) and LDS (IPS e.max CAD) specimens, (5 mm in width, 5 mm in length and 1.5 mm in height) were fabricated using CAD/CAM and sintered according to the manufacturer’s instructions. All specimens subjected to three surface treatment combinations; etching with 4% hydrofluoric acide (HF), airborne-particle abrasion with 110-μm alumina (Al2O3) (AP) and Er:YAG laser (Er:YAG) (Group A—HF + AP; Group B—Er:YAG + AP, and Group C—Er:YAG + HF). Perthometer was used to measure the surface roughness of the specimens before and after the tretments. Results Group A presented the highest Ra (LDS 0.81 ± 0.27 and ZrO2 0.67 ± 0.21 after treatment) and Group C the lowest (LDS 0.45 ± 0.13 and ZrO2 0.26 ± 0.07, after treatment). Compared with before treatment, the Ra were significantly different only in Group A both ZrO2 and LDS after treatment (p

The development of superior low-temperature catalytic performance and inexpensive catalysts for the removal of volatile organic compounds (VOCs) is crucial for their industrial application. Herein, CuO/Ce0.6Zr0.4O2 catalysts calcinated at different temperatures (Cu/CZ-X, X represented calcination temperature) were prepared and used to eliminate toluene. It can be found that Cu/CZ-550 presented the highest low-temperature catalytic activity, with the lowest temperature (220 °C) 50% conversion of toluene, the highest normalized reaction rate (3.1 × 10−5 mol·g−1·s−1 at 180 °C) and the lowest apparent activation energy value (86.3 ± 4.7 kJ·mol−1). Systematically, the surface properties analysis results showed that the optimum redox property, abundant oxygen vacancies, and plentiful surface Ce3+ species over Cu/CZ-550 were associated with the strong interaction between Cu and support could significantly favor the adsorption and activation of toluene, thus resulting in its superior catalytic performance. [ABSTRACT FROM AUTHOR]

In this review, advances in scanning probe microscopy (SPM) from the last two decades are presented. Progress in analyzing C60 molecules is described as an example of molecular imaging quality improvement for each decade. Innovations and progress in SPM imaging techniques are then outlined, especially atomic force microscopy operating in ultrahigh vacuum (UHV) or in aqueous environments, and the widely spread low-temperature and/or highperformance UHV scanning tunneling microscopy. [ABSTRACT FROM AUTHOR]

This research is aimed towards a facile one-step preparation of magnetic poly(styrene-glycidyl methacrylate)-Fe3O4 nanocomposite particles named as P(S-GMA)-Fe3O4. The nanocomposite particles are prepared by a simultaneous free-radical copolymerization and co-precipitation of Fe2+ and Fe3+ salts. Two variable w/w ratios of styrene to GMA (98/2 and 96/4) are used. But, the overall copolymer to iron oxide ratio is kept identical. The structural analyses and morphology revealed the uniform distribution of Fe3O4 nanoparticles and the nanocomposites showed paramagnetic property. The potentiality of nanocomposite particles as glucose bisenosors via adsorption of glucose oxidase (GOD) is investigated using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A comparative analysis of the glucose concentration dependent current response suggested that the modified electrode fabricated from P(S-GMA)-Fe3O4(2) (w/w ratio, 98/2) possessed superior response to other electrodes made from PS, P(S-GMA), PS-Fe3O4 and P(S-GMA)-Fe3O4(4) (w/w ratio, 96/4), respectively. The P(S-GMA)-Fe3O4(2)/GOD/Pt biosensor could measure glucose in the range of 2.2 × 10− 4 to 6.0 × 10− 3 M with a sensitivity of 14.47 µA mM− 1 and exhibited a detection limit of 5.07 µM at a signal to noise ratio of 3. The value of Michaelis-Menten constant (Km) is calculated as 0.019 mM. Overall results indicate that P(S-GMA)-Fe3O4(2) nanocomposite prepared in one-step is suitable for use in glucose biosensors. [ABSTRACT FROM AUTHOR]

Phosphate rock flotation is a widely used method in phosphate rock processing in which aimed minerals are selectively separated from gangue minerals based on the difference in surface wettability. Due to its associated minerals in phosphate rock, there is always a lot of Mg2+, Al3+ and Fe3+ in phosphate rock slurry. The existence of metal ions, whose forms are changed with slurry pH, can affect the flotation operation by adsorption on the mineral surface. The surface properties of minerals are the main factors affecting their dispersion, aggregation, and flotation behavior. Herein, the influences of unavoidable metal ions, including Mg2+, Al3+ and Fe3+, on the surface properties of fluorapatite (FAP) in pulp were studied by solution chemical calculation, turbidity, contact angle and Zeta-potential test. The results showed that the forms of metal ions in solution vary with pH. FAP is a hydrophilic mineral, and the influence of adding Fe3+ ions on the wettability of FAP was greatly affected by pH. In acidic environment, Fe3+ ions could promote the hydrophilicity of FAP, while in neutral and alkaline environment, Fe3+ ions could inhibit the hydrophilicity of FAP. The effects of Mg2+ and Al3+ ions were less affected by pH, and both Mg2+ and Al3+ ions inhibited the wettability of FAP in neutral environment. In the range of pH 3-11, Mg2+ mainly existed as divalent ions, which compressed the double layer on the FAP surface. Al3+ and Fe3+ mainly generated hydroxide precipitation through hydrolysis to cover the surface of FAP. Mg2+, Al3+ and Fe3+ ions would destroy the dispersity of FAP and promote the coagulation of FAP. [ABSTRACT FROM AUTHOR]

Abstract A comprehensive comparison of the trends and drivers of global surface and canopy urban heat islands (termed Is and Ic trends, respectively) is critical for better designing urban heat mitigation strategies. However, such a global comparison remains largely absent. Using spatially continuous land surface temperatures and surface air temperatures (2003–2020), here we find that the magnitude of the global mean Is trend (0.19 ± 0.006°C/decade, mean ± SE) for 5,643 cities worldwide is nearly six‐times the corresponding Ic trend (0.03 ± 0.002°C/decade) during the day, while the former (0.06 ± 0.004°C/decade) is double the latter (0.03 ± 0.002°C/decade) at night. Variable importance scores indicate that global daytime Is trend is slightly more controlled by surface property, while background climate plays a more dominant role in regulating global daytime Ic trend. At night, both global Is and Ic trends are mainly controlled by background climate.

Summary: Droplets directionally bouncing off moving superhydrophobic solid surfaces are universal in nature and are crucial in many biological, sustainable, environmental, and engineering applications. However, their underlying physics and regulation strategies remain relatively unknown. This paper demonstrates that the maximum directional acceleration of a post-impact droplet mainly occurs in the spreading stage and that the orientational velocity of the droplet mainly originates in the early impingement process. Furthermore, it clarifies the underlying physics based on momentum transfer process imposed by the boundary layer of impacts and proposes a strategy for regulating the directional droplet velocity using a comprehensive formula. Finally, it shows that directional bouncing reduces the flight momentum of a small flying device by 10%–22%, and the experimental values agree closely with the predicted values. This study reveals the droplet bounce orientation mechanism imposed by moving substrates, provides manipulation methods, and makes positive and meaningful discussions of practical applications.

To protect the ancient wood against water destroy, the waterborne polyurethane was modified siloxane and then painted on the wood surface. The coated surface was characterized and the surface physical and mechanical properties were tested. The results showed that the siloxane can be grafted onto the polyurethane by reacting between Si-OH groups and the end N=C=O groups. Thus, after coating on the wood surface, a network structure was formed for improvements. The polyurethane can form a layer of film on the wood surface while the siloxane can help to make a smooth coating film owing to the improved interfacial adhesion. With the increase of siloxane content, the surface became better with improved water contact angle, swelling dimensional stability, and hardness. At 3 wt% siloxane, the surface properties of the wood showed high water repellency and acceptable mechanical properties, which can be used for ancient timber protection. [ABSTRACT FROM AUTHOR]

Low-frequency vibration cutting is a machining technology in which chips are broken by applying periodic vibrations along a specific axis. Periodic vibration deteriorates the surface roughness and roundness of the workpiece when compared to without vibration cutting. In this study, the properties of a machined surface under low-frequency vibration were simulated. Based on the simulation results, a tool was designed to reduce the effects of periodic vibration on the surface properties. Actual machining experiments were conducted using the proposed tool to clarify the relationship between tool shape, surface roughness, and roundness under low-frequency vibration. Using the proposed tool on low-frequency vibration cutting, the surface roughness was reduced (from 5.74 µm to .94 µm in Ra and 23.09 µm-6.66 µm in Rz), average roundness improved (from 4.73 µm to 2.95 µm), and maximum roundness decreased (from 15.34 µm to 3.61 µm) compared with those of the conventional tool. [ABSTRACT FROM AUTHOR]

[Display omitted] Mixed clays (e.g. montmorillonite, illite and kaolinite) are ubiquitous in hydrate-bearing sediments under seafloor, and their surfaces inevitably affect the formation of natural gas hydrates therein. Nevertheless, the actual effects of clay surfaces on hydrate formation remain elusive. Systematic molecular dynamics simulations have been performed to investigate CH 4 hydrate formation in mixed clay nanopores of montmorillonite, illite and kaolinite, to examine the effects of surface property and layer charges of mixed clays. Simulation results indicate that the surfaces of mixed clays affect CH 4 hydrate formation in the nanopores by changing the CH 4 concentration (x CH4) and ion concentration (x ions) in the middle region of the nanopores via surface adsorption for CH 4 , H 2 O and ions. Specifically, the surfaces of montmorillonite and illite, the siloxane and gibbsite surfaces of kaolinite show different affinities for adsorbing CH 4 , H 2 O and ions, which can significantly affect the x CH4 and x ions in the interfacial and middle regions of the nanopores. Moreover, hydrate growth shows certain surface preference. These molecular insights into the effect of mixed clay surfaces on CH 4 hydrate formation can help to understand the formation mechanism of natural gas hydrate in marine sediments. [ABSTRACT FROM AUTHOR]