Smooth Surface Research Articles

Cubism in America: Modernist explorations and domestic concerns

American artists started to become aware and knowledgeable of cubism around 1910 through the galleries of Daniel-Henry Kahnweiler and Alfred Stieglitz, exhibitions like the Armory Show, private collections like Leo and Gertrude Stein and Arthur Jerome Eddy, and publications like The Rise of Cubism and Camera Work. Some of the best and earliest American cubists were Max Weber, Marsden Hartley, Lyonel Feininger, Charles Demuth, H. Lyman Säyen, Stuart Davis and Charles Sheeler. American cubists were very interested in the so-called “salon cubists” or “Puteaux cubists”, such as Fernand Léger and Albert Gleizes. Weber and Hartley developed personally distinctive styles that combine aspects of expressionism and cubism for social observation and personal revelation. American cubism developed two interconnected stylistic tendencies that are particularly American: billboard cubism and precisionism. They are characterized by sharp contours, flattened, emphatically geometric and abruptly juxtaposed forms, smooth and bright surfaces, clear mechanical and industrial references, and references to advertising, packaging, logos and labels. This extremely American sensibility is seen in the work of Davis, Demuth and Sheeler.

Curcumin‐Loaded Co‐Axial Electrospun Chitosan/Polyvinyl Alcohol/Calcium Chloride Nanofibrous Membranes for Wound Healing Enhancement

AbstractNanofibrous membranes were developed by combining chitosan (CS), polyvinyl alcohol (PVA), and calcium chloride (CC) to incorporate curcumin (CCM) through a co‐axial electro‐spinning method to improve CCM bioavailability. The optimal parameters were PVA/CS ratio of 7:3 v/v, PVA/CCM ratio of 8:2 v/v, CC amount of 0.5 g, fiber collection distance of 15 cm, voltage value of 18 kV, and injection flow of 0.1 mL/h (both core and shell layer). The prepared PVA/CCM@CS/PVA/CC nanofiber showed smooth surfaces and uniform bead‐free morphology with core‐shell structure. The average fiber diameter was 301.55 ± 76.77 nm with a narrow distribution. Using the Korsmeyer‐Peppas kinetic release model, the nanofiber membrane effectively released ∼85% CCM at pH 7.4 over 96 h via Fickian diffusion transport mechanism. In vitro antibacterial tests demonstrated that the membrane was efficient against both Gram‐positive (Staphylococcus aureus) and Gram‐negative (Pseudomonas aeruginosa) bacteria. When compared to free CCM, the membrane improved cell survival due to its nontoxic and cytobiocompatible features. In vivo tests found that the membrane significantly improved healing in incised‐wound rats, reducing inflammation, fibroblast proliferation, and collagen deposition. These findings indicate that the novel PVA/CCM@CS/PVA/CC nanofiber membrane, which has numerous biological functions, could be a promising candidate for wound dressing therapeutic applications.

Pure copper coating by multibeam directed energy deposition with blue lasers for antimicrobial effect

Pure copper has antimicrobial effect, and the development of pure copper coating technology for product surfaces is needed to prevent the spread of infections. To achieve high antimicrobial performance in coatings, it is essential to form a coating with high copper purity and minimal defects. In this study, we attempted to form a pure copper coating layer on a SS304 substrate using multibeam directed energy deposition with blue diode lasers. In the coating layer formation process, multiple bead layers are overlapped to form a smooth surface and two different types of joining is conducted simultaneously: the similar material joining area with the remelted previous layer, and the dissimilar-material joining area with the substrate. However, it was challenging to conduct this process for SS304 and pure copper due to their significantly different thermal properties. Therefore, we varied the hatching distance to control the heat input to both joining areas and investigated the effect on the quality of the coating layer. The results showed that there is an optimal ratio of similar and dissimilar joining areas, at which a high-quality coating layer with few voids and low dilution is formed. Furthermore, antimicrobial tests showed that the pure copper coating layer formed in this study exhibited the antimicrobial performance equivalent to those of a pure copper plate.

Effect of Laser Powder Bed Fusion Parameters on the Evolution of Melt Pool, Densification, Microstructure, and Hardness in 420 Stainless Steel Parts

Laser powder bed fusion (LPBF) involves depositing, melting, and solidifying metal powder particles layer by layer to create 3D components. In this study, a deep fundamental understanding on how process parameters—laser power, scan speed, and hatch spacing—affect the melt pool, densification, microstructure, hardness, and thermal behavior of 420 stainless steel (420SS) parts produced by such technology is provided. The conducted investigation considers five levels of laser power and hatch spacing, and four scan speeds. Optimal single tracks, based on geometry and profile, are achieved with laser powers between 40 and 80 W and a scan speed of 10 mm s−1. In the multitrack analysis, it is indicated that a dense, smooth surface is obtained with a hatch spacing of 250 μm, corresponding to an overlapping rate of ≈30%. The 420SS samples show high densification (≈99%) and low surface roughness (≈3.62 μm). The microstructure consisted of martensite laths and retained austenite. The hardness and thermal conductivity of the samples are measured at 540 HV and 15.3 W m−1 K−1, respectively. In this study, the understanding of the process–structure–property relationships in LPBF of 420SS is expanded.

Spatial analysis of Holocene delta compound clinoforms

Recognition of compound delta clinoforms has led to a new understanding of delta progradation and architecture. Limited study has been dedicated to spatially delineate three dimensional morphologies of subaqueous deltas and their migration away from active sediment sources. Qualitative and quantitative analyses of 38 Holocene deltas lead to the observation of two main gradient breaks at tens-of-meters water depth and variable subaqueous geometries. Geometric variability was captured relative to riverine-sediment sources and basinal energies and presents steeper shoreline and subaqueous delta clinoforms, reaching 1°, separated by a gently-dipping 0.11° platform with widths from few kilometers (Ebro Delta) to 200 kilometers (Amazon Delta). In wave-dominated systems, the platform is absent ahead of the sediment source but widens laterally away as a smooth arcuate surface, whereas in tide-dominated systems the platform widens ahead of active sources and narrows ahead of starved ones while hosting erosional features and tidal channel/bar couplets.

Efficient synthesis of cellulose acetate through one-step homogeneous acetylation of cotton cellulose in binary ionic liquids

Cellulose acetate (CA) is an important cellulose derivative with a wide range of applications. To adopt a more efficient and environmentally friendly method to synthesize cellulose acetate, a binary ionic liquid mixture of 1-butyl-3-methylimidazole chloride salt (BmimCl) and 1-butyl-3-methyldihydroimidazole phosphate (BmimH2PO4) was used. Compared to the conventional methods, this approach didn't require pre-activation of cellulose and the process of homogeneous acetylation proceeded without a catalyst. By simply adjusting the reaction conditions, cellulose acetate with a degree of substitution (DS) in the range of 0.83–3.0 was produced by one-step homogeneous acetylation without hydrolysis. Furthermore, the cellulose acetate film produced by solvent casting exhibited smooth surface characteristics, 95 % transparency, and 57.9 MPa tensile strength. Therefore, this study highlights the importance of using binary ionic liquid mixtures for facile synthesis of cellulose acetate. Due to their excellent transparency and mechanical properties, newly synthesized cellulose acetate films could replace commercial films.

Interaction of a UWB impulse with a layer of sandy soil, having a rough upper boundary

ABSTRACT In this paper, the changes in the character of time shapes, amplitudes, frequency spectra, and time delay of ultra-wideband (UWB) impulses (duration of 0.33 ns) reflected from the layer of wet sand with a rough upper boundary were investigated. It was shown that the attenuation of UWB impulse amplitude, which is reflected from the upper rough boundary of the sand layer, can be described by the model of Fresnel reflection coefficient for a smooth surface using the Gaussian correction factor (FRGC). At this root-mean-square (RMS), height of soil surface roughness was in the range of ~0–21 mm, but the determination coefficient and RMS error (RMSE) were found to be equal to 0.94 and 0.02, respectively. An experiment close to linear increase/decrease in the propagation time of impulses reflected from the upper/lower boundary of the layer, respectively, was found with increasing the RMS heights of upper boundary. It is shown that the propagation time of such impulses can be described by the modified FRGC model with an error from RMSE = 0.09 ns to RMSE = 0.15 ns. The results of these findings are of practical importance for the interpretation of remote sensing data for precise soil moisture measurements from unmanned aerial vehicle platforms using UWB impulses.

Binary imidazolium based aqueous ionic liquid droplet on a rough surface: a molecular dynamics study

Ionic liquids (ILs) have garnered immense attention due to their tunable physicochemical properties. In this study, we delve into the wetting behaviour and interfacial properties of aqueous binary IL mixtures containing [EMIM] [BF4] and [HMIM] [BF4] on both smooth and rough graphite surfaces. Employing classical molecular dynamics simulations, we systematically explored the effects of IL concentration and surface morphology on wetting phenomena. To ensure the equilibrium of the systems, we began by calculating the interaction energies between the components. Subsequently, contact angles were computed, shedding light on the wetting characteristics of the aqueous binary IL mixtures. We meticulously examined the density profiles of the IL systems from the substrate to unravel the dominance of one IL over the other, exploiting the hydrophilic nature of [EMIM] [BF4] and the hydrophobic nature of [HMIM] [BF4]. A comprehensive analysis of hydrogen bond distribution allowed us to discern the intricate nature of these aqueous binary IL droplets. We probed the changes in intermolecular forces within the aqueous IL solution by investigating surface tensions. The tunability of these ILs emerges as a significant aspect of our study, paving the way for their tailored application in engineering and scientific domains. Schematic diagram showing the density distribution of hydrophilic and hydrophobic ILs ([EMIM] [BF4] and [HMIM] [BF4]) in water and also the hydrogen bond (HB) distribution of anion ([BF4]−) water inside the droplet on a pillared surface with a surface fraction ( f ) of 0.4 and pillar height of H = 4 .

Streptomyces albidocamelliae sp. nov., an endophytic actinomycete isolated from the leaves of Camellia oleifera.

A novel actinobacterium strain, HUAS 14-6T, was isolated from the healthy leaves of Camellia oleifera collected from Changde City, Hunan Province, China. Strain HUAS 14-6T produced tight spiral spore chains consisting of oval or spherical spores with a smooth surface. 16S rRNA gene sequence analysis revealed that strain HUAS 14-6T belonged to the genus Streptomyces and shared highest similarity to Streptomyces bungoensis DSM 41781T (99.72%). Phylogenetic analysis based on 16S rRNA gene sequences indicated strain HUAS 14-6T was in a clade with S. bungoensis DSM 41781T. However, the ANIm and dDDH between strain HUAS 14-6T and S. bungoensis DSM 41781T were 88.16% and 31.2%, respectively, far less than the species-level thresholds. Phylogenetic trees based on the five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) showed that strain HUAS 14-6T formed a separate branch, indicating that this strain could belong to a potential new species. Pairwise MLSA distances between strain HUAS 14-6T and all type strains exhibiting 16S rRNA gene sequence similarities of ≥98.7% to it were much higher than the maximum range of 0.014 recommended for delineating a new Streptomyces species. Based on polyphasic taxonomic study, HUAS 14-6T represents a novel species within the genus Streptomyces for which the name Streptomyces albidocamelliae sp. nov. is proposed. The type strain is HUAS 14-6T (=MCCC 1K08365T=JCM 35920T).

Mechanical properties, nano-tribological behavior and deformation mechanism of FeCrNi MEA with the addition of Co/Cu: Molecular dynamics simulation

During manufacturing processes, alloys face increasingly demanding requirements for their mechanical and tribological properties, underscoring the importance of revealing their deformation mechanisms. This study employed molecular dynamics simulation to construct models of FeCrNi (C1), FeCoCrNi (C2), FeCrNiCu (C3), and FeCoCrNiCu (C4), investigating the tribological properties of C1 alloy under various conditions and the mechanical properties across a wide temperature range (223–1073 K). The results indicate that the elastic modulus of the alloys follows the order C2 > C4 > C3 > C1 across the temperature range of 223 K to 1073 K. The elastic modulus increases with rising temperatures and decreases before rising once again as temperatures decrease. The phase transitions become more pronounced below 300 K. The addition of Co elements to the FeCrNi alloy contributes to fine-grain strengthening, uniform distribution of internal stress and strain, reduction in local stress concentration, and improvement of the alloy ductility and tensile strength. Compared to sliding friction, rolling friction reduces the number of worn atoms; however, the tensile and shear effects cause an increase in the stress gradient, leading to more severe subsurface damage and shear deformation. Temperature significantly affects the tribological properties of the alloys: phase transitions at high temperatures promote dislocation slip and plastic deformation, while at low temperatures, higher hardness and strength are observed. The roughness of stacking faults is greatly influenced by temperature, with an increase at the low-temperature range (223–273 K), a decrease in the mid-temperature range (273–673 K), and a smoother surface at the high-temperature range (673–1073 K). The research aims to provide a deeper understanding of the excellent mechanical and tribological properties of FeCrNi alloy at the micro/nano scales, thereby advancing their application and development in manufacturing processes.

Polyethylene glycol enhanced antibacterial activity of EDTA and ethyl maltol blended PLA against Staphylococcus aureus for biodegradable active packaging

Poly (lactic acid) (PLA) has limited promise as a bio-based antimicrobial packaging material due to its lack of plasticization, which limits antimicrobial agent release and antimicrobial efficiency. PLA were plasticized with polyethylene glycol (PEG) and blended with ethyl maltol or ethylenediaminetetraacetic acid (EDTA) as antibacterial agents by melt extrusion. The effects of combining PEG, EDTA, and ethyl maltol on sheet properties and antibacterial activity were investigated. Incorporation of ethyl maltol created a dense and smooth homogeneous surface, while EDTA addition caused large pores in the PLA sheet microstructure impacting swelling degree, water solubility and surface hydrophilicity. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) showed that both ethyl maltol and EDTA addition modified the amorphous and crystalline phases of plasticized PLA. FTIR results suggested interaction between the functional groups of PLA chains, PEG, ethyl maltol or EDTA which affected the glass transition temperature (Tg), degree of crystallinity, and thermal stability of PLA. Adding PEG into PLA-EDTA enhanced antibacterial activity against Gram-positive Staphylococcus aureus (reduction of 1.35 log CFU/mL from the initial inoculum). The higher water solubility of sheets corresponded to a suitable release rate and sufficient amounts of antimicrobial compounds against Staphylococcus aureus. In vitro antifungal testing, PLA-PEG-EDTA sheets did not exhibit a clear zone of inhibition but delayed Penicillium sp. spore formation until day 5 of incubation. PEG plasticized PLA sheets functionalized with ethyl maltol and EDTA showed potential as active biomaterials against food-borne pathogen bacteria Staphylococcus aureus.

Single activator doped fluoride nanoparticles for X-ray excited high-resolution and delayed flexible nonplanar imaging

Lanthanide doped fluoride nanoparticles (NPs) exhibit adjustable X-ray excited optical/persistent luminescence (XEOL/XEPL) and possessing extensive potential in XEPL-based delay imaging. However, the high-resolution and delayed XEPL-based delay imaging always requires strict introduction of sensitized or heterovalent ions and the construction of complex structures for excellent XEPL performance of lanthanide-doped fluoride NPs, which is attributed to a lack of effective and convenient strategies. Here we show that the intense XEPL strength was obtained by single Tb3+ activated ion doping and simple CsY2F7@NaYF4 core/shell structure for X-ray excited high-resolution and delayed flexible nonplanar imaging. The strict introduction and control of sensitized or heterovalent ions, and the construction of intricate multilayer nanostructure are avoided. In addition, we enable the NPs to achieve high and long-term XEPL performance by simply thermal processing strategy. We successfully mixed minimized amount of the NPs into flexible film to create a scintillation screen which consequently exhibit high surface smoothness, environmental stability, and transparency. Our results demonstrate high resolution delayed imaging of the NPs integrated flexible film for the interior of nonplanar objects. The spatial resolution of 14.3 lp mm−1 is substantially higher than the typical spatial resolutions required for medical CT scans (2 lp mm−1) and X-ray imaging (3.5 lp mm−1). These findings will promote the development of advanced delayed X-ray nonplanar imaging applications.

Three–dimensional matrices for enhanced coral settlement through design for additive manufacturing

Purpose The effects of climate change have been contributing to coral reef degradation. Artificial reefs are one method being used to counteract this destruction. However, the most common artificial approaches, such as sunken vehicles and prefabricated cement reefs, do not allow adequate coral development. This paper aims to demonstrate how designers, using additive manufacturing and computational design techniques, can create artificial reefs that better mimic natural reef structures. Design/methodology/approach This research focuses on developing three-dimensional matrices through computational design using additive manufacturing to achieve better coral settlement. A “Nature Centered Design” approach was followed, with the corals at the center of the design project. Samples with different geometries and roughness, produced using paste-based extrusion with porcelain and porcelain with oyster shell, were tested in a controlled environment to investigate the settlement preference of soft corals. Findings The rapid prototyping of samples confirmed the preference of corals to settle to complex surfaces compared to smooth surfaces. Porcelain showed comparable results to Portland cement, suggesting further testing potential. A closer resemblance to the natural and intricate forms found in coral reefs was achieved through computational design. Originality/value This paper proposes a new approach combining rapid prototyping with coral’s biological responses to enhance the understanding of their surface settlement preference. The Nature Centered Design approach, with additive manufacturing and computational design, made it possible to create an innovative working model that could be customized depending on the implementation area or intended coral species, validating the design approach as a method to support environmental conservation.

B-064 Bovine Serum Albumin Coats Silicon Dioxide More Uniformly Near its Isoelectric Point Based on Atomic Force Microscopy Analysis

Abstract Background Bovine serum albumin (BSA) serves as a blocking agent in in-vitro diagnostic (IVD) applications, with fatty acid stabilized (FAS) and fatty acid free (FAF) BSA as common options. The presence of fatty acids and pH influence the conformation of BSA. While previous studies have explored the individual effects of fatty acids or pH on BSA blocking, limited data exists on their combined impact. This study employs atomic force microscopy (AFM) to investigate how pH and fatty acids jointly affect BSA adsorption onto silica, a surface relevant within diagnostics. Methods AFM, a sensitive microscopic technique, provides topographic images of surfaces with superior resolution compared to optical microscopy. We conducted experiments to assess the adsorption of 1% FAS and FAF BSA on a silica surface at pH 5.2 and pH 7. Evaluation of the coatings involved scratching to assess overall thickness, and roughness, indicating thickness variability. Results Results revealed that both fatty acids and pH play significant roles in shaping the BSA coating characteristics on silica surfaces. In three out of four experimental conditions, the average thickness of the BSA coating ranged between 3-4 nm, except for FAS BSA at pH 7, which exhibited a thicker average coating measuring 5.6 nm. The pH impacted the roughness of the BSA coating. Coatings prepared at pH 5.2 displayed smoother surfaces compared to those at pH 7. Utilizing the root mean square average height variability analysis, there is 95% confidence that the FAF and FAS BSA surfaces at pH 5.2 had a height range between 2.4-4.3 nm and 2.0-4.9 nm, respectively, indicating complete coverage of the silica surface without much height variation. In contrast, the FAF and FAS BSA coatings at pH 7 exhibited a wider range of heights, with 95% confidence intervals spanning from -1.5-8.6 nm and 0.0-11.2 nm, respectively. This variability suggests potential issues including incomplete BSA coverage at the lower range, and steric hindrance at the higher end, highlighting the importance of pH in optimizing BSA coatings for various applications. Conclusions Silica is commonly used in IVD assays, with BSA frequently employed to coat and passivate the surface. Our AFM experiments highlight the impact of pH and fatty acid presence on coating thickness and uniformity. Notably, FAS BSA at pH 7 exhibited the thickest coating; however, its increased roughness may pose challenges in IVD applications due to steric hindrance blocking antibody-antigen interactions. Alternatively, FAF BSA at pH 7 displayed an adequate thickness but also considerable roughness, suggesting potential insufficiencies in surface coverage and passivation. FAS and FAF BSA coatings at pH 5.2 showed relatively consistent thickness, indicating a more uniform surface which may be ideal for IVD coating applications. These AFM experiments were conducted on pure silica surfaces, which may differ from surfaces engineered for IVD. Additionally, both FAF and FAS BSA grades are proven to be effective in IVD applications. Further research employing AFM and other biophysical techniques is warranted to deepen our understanding of pH and fatty acid effects on BSA-surface interactions, aiming to enhance blocking strategies in IVD.

Effect of pin fins on heat transfer during condensation in minichannel heat exchanger

In this study, condensation heat transfer of water vapor in a minichannel heat exchanger on smooth and pin fins surfaces was investigated experimentally. The experimental study was carried out to evaluate heat transfer coefficient, overall heat transfer coefficient, and Nusselt number over different ranges of vapor mass flux from 0.0064 to 0.0368 kg m−2 s−1 and cold-water flow rate range between 0.0013 kg s−1 to 0.0057 kg s−1. The minichannel has a rectangular shape with a hydraulic diameter of 1.3 mm. The experimental testing is carried out on aluminum surface with a channel that has a length of 270, width of 30 mm, and height of 1.3 mm. The pin fins surface is on the bottom of the condensing channel and the fins are circular and have diameter, height, and spacing of 1 mm, and are in-inline arrangement. It is found that condensation heat transfer coefficient on pin fins surface is about 15% higher than that on smooth surface. It is found that the condensation heat transfer coefficient increases significantly with increasing the vapor mass flux. In addition, the effect of increasing the cold fluid flow rate is lower than that of the hot vapor flow rate, but it becomes more significant for higher vapor flux.

Effect of eco-friendly organic additives on copper electropolishing and process parameter optimization

The type of organic additives significantly affects copper electropolishing performance, including glossiness and surface smoothness. Therefore, developing efficient and eco-friendly additives is crucial for advancing this technology. This study investigates the effects of glycerol and ascorbic acid on copper electrochemical properties and surface morphology. Using the Box- Behnken Design (BBD), we examined the interaction effects of polishing time (A), current density (B), and polishing temperature (C) while optimizing the process parameters. The results demonstrate that glycerol and ascorbic acid additives effectively reduce the critical current density and limiting current density, synergistically enhancing copper surface glossiness and smoothness while slowing down the dissolution rate of the copper. Interaction analysis revealed a prioritized sequence of effects: AB > BC > AC. Under optimal conditions (1.5 min of polishing time, 12 A dm−2 of current density, and 27 °C of polishing temperature), copper surface roughness decreases from 1.2 μm to 37 nm, representing a 97% reduction, along with enhanced corrosion resistance.

Numerical and experimental investigation of additive manufactured heat exchanger using triply periodic minimal surfaces (TPMS)

With the increasing demand for high-efficiency compact heat exchangers in automobiles and spacecraft, lighter and more efficient metamaterials hold promise as advanced materials for cooling applications but remain beyond reach. Triply Periodic Minimal Surface (TPMS) structures, characterized by their smooth surfaces and significantly huge volumetric surface area, represent ideal internal structures for heat exchangers, and the development of additive manufacturing has made their design and production possible. This study focuses on designing heat exchangers based on seven TPMS structures (Fischer-Koch S, Gyroid, SplitP, Diamond, I-WP, F-RD, Primitive) and prints the finished heat exchangers using AlSi10Mg material based on numerical investigation results. Comprehensive evaluation metrics are used to rank the results. The findings reveal that the internal interleaved channels have varying effects on different structures, with Fischer-Koch S exhibiting the highest heat transfer capability of up to 269 W/K. Gyroid and I-WP demonstrate the best fluidity, with resistance only 23.44 % of Primitive’s. Gyroid has the best overall evaluation metrics, with a 54 % efficiency improvement over traditional plate heat exchangers. Additionally, this study proposes the use of the Voronoi algorithm to handle the channels of TPMS and identifies the asymmetric characteristics of heat exchangers on both sides, and it is believed that there is still greater optimization potential for the performance of TPMS heat exchangers

Nanoparticles based on whey and soy proteins enhance the antioxidant activity of phenolic compound extract from Cantaloupe melon pulp flour (Cucumis melo L.)

The phenolic compounds (PC) present in the pulp flour of Cantaloupe melon (Cucumis melo L.) were encapsulated in whey protein isolate (EPWI), whey protein concentrate (EPWC), and soy protein isolate (EPSP) by nanoprecipitation to evaluate the effect on the antioxidant potential in vitro. The crude extract was evaluated for the content and profile of PC, presenting 750 ± 60.73 mg EAG/100 g and ten different types with emphasis on procyanidin B1 (213.9 ± 33.23 mg/kg) and fumaric acid (181.6 ± 30.55 mg/kg). The characterization indicated the incorporation efficiency of PC in the range of 74.10 ± 0.28–90.60 ± 6.52 %, formation of spherical particles with smooth surfaces, average diameters between 74.90 ± 10.78–96.57 ± 10.17 nm, amorphous structure, and chemical interactions between the materials, justifying the potentiation of the antioxidant activity of the crude extract by up to six times (p < 0.05). Therefore, nanoencapsulation using protein materials and the nanoprecipitation technique is a promising strategy to promote the encapsulation of PC from Cantaloupe melon.

Molecular dynamics of CH4 adsorption and diffusion characteristics through different geometric shale kerogen nanopores

In shale, pore structure plays an extremely significant effect on CH4 storage and transportation in a reservoir, especially for the reservoir involving large amounts of extremely tiny nanopore and variance of microstructure. In this study, three molecular dynamics models for different types of kerogen nanopores such as serration type, arc type and great-wall type are established, validated and implemented to assess the impact of pore structure on CH4 adsorption and diffusion behaviors in kerogen matrix and nanopore at temperature 320 ∼ 380 K, pressure 5 ∼ 20 MPa and pore size 3 ∼ 5 nm. The simulation results demonstrate that the CH4 density in the bulk of serration-type, arc-type and great-wall-type pores is 1.6, 1.3 and 1.9 higher than that inside kerogen molecules. Increasing temperature can weaken the adsorption capacity of kerogen, but the serration-type pore is the most sensitive to temperature. Regardless of the pore type, increasing pressure can significantly enhance the adsorption capacity of kerogen which is almost unaffected by pore size, whereas the CH4 diffusion coefficient increases with pore size. Furthermore, the great-wall-type pore can adsorb more CH4 molecules due to its smooth surface, followed by change in the arc-type and serration-type pores in turn. Among these types of pores, the CH4 diffusion coefficient is the most insensitive to the size of arc-type pore. Hence, the influences of kerogen pore structure under different conditions of temperature, pressure and pore size are quantified in this work to improve a comprehensive understanding of CH4 adsorption and diffusion behaviors in shale, thereby contributing to high-efficient and sustainable development of shale gas reservoirs.

High-modulus engineered cementitious composites: Design mechanism and performance characterization

Engineered cementitious composites features with high tensile performance while relatively weak compressive stiffness. This study endeavors to address the inherent trade-off between tensile properties and elastic modulus in conventional Engineered Cementitious Composites (ECC). Utilizing the distinctive characteristics of iron ore aggregates, known for their relatively stiff nature, smooth surface and rounded shape, an Iron Sand-based ECC (IS-ECC) emphasizing both high elastic modulus and ductility is formulated. Guided by micromechanical design theory and multiscale homogenization model, this study systematically explores the impacts of aggregate types, water-to-binder (w/b) ratios, sand-to-binder (s/b) ratios, and sand particle sizes on ECC properties. Compared with Quartz Sand-based ECC (QS-ECC), IS-ECC exhibits notably enhanced matrix fluidity and elastic modulus, reduced matrix toughness, and more robust strain-hardening behavior. The proposed three-level multiscale homogenization model accurately predicts the elastic modulus of ECC and provides insights into the underlying mechanism contributing to the enhanced elastic modulus of IS-ECC. With a resulting high elastic modulus of 33.3–48.6 GPa and superior tensile properties, IS-ECC holds promise for widespread applications in structural engineering.