Sheet Surface Research Articles

Identification of structural defects and their impact on the magnetic memory, static and cyclic strength of VNS9-SH thin sheet trip-steel

Identification of microstructure defects, which are stress concentrators (SC) during the operation of mechanical engineering products, is an important scientific and practical task relevant for manufacturing enterprises. This problem becomes especially urgent and difficult for critical helicopter parts made of sheet TRIP steel VNS9-Sh (23Kh15N5AM3-Sh) and operating under cyclic loads due to the complex microstructure of the steel and small thickness of strips and sheets. To assess the impact of structural defects on the cyclic strength of products made of the steel under study, the specimens were preliminary sorted proceeding from the results of their testing using the method of metal magnetic memory (MMM) and metallographic studies. The MMM method is a structure-sensitive procedure which provides information about the presence of structural defects that arise during the manufacture. Magnetic anomalies in the form of sharp local changes in the intrinsic stray magnetic field (SSMF) (H) and its gradient |ΔH| along the length of the controlled section Δx, were identified on the surface of sheets cut from five different batches. A conventional classification of the identified anomalies was made according to the magnitude of the magnetic field gradient. The specimens of two types were cut in zones of magnetic anomalies and outside them: type 1 — for cyclic tests and type 2 — for metallographic studies. The geometric parameters and field gradient values of magnetic anomalies on specimens of type 1 and type 2 were the same. Metallographic studies in zones of maximum magnetic field gradient on type 2 specimens revealed defects in the form of a strip at the boundary of different structures, which is a structural stress concentrator (SSC) and a source of the inhomogeneity and changes in the magnetic properties. Type 1 specimens with similar magnetic anomalies and Type 1 specimens cut from sheets outside zones of magnetic anomalies were then selected for cyclic testing. Comparative tests for cyclic strength of the specimens with and without specified SSC were carried out. It is shown that the presence of SSC zones in the specimens reduces the number of cycles to failure during cyclic tests by 1 – 2 orders of magnitude compared to the specimens free of SSC. Based on cyclic tensile tests of specimens, a limiting value of the magnetic field gradient was determined that corresponds to the acceptable level of stress concentration on structural defects. This value is recommended for use as a rejection criterion when examining a new tape by the MMM method.

Investigation on damage evolution mechanism of various FRP strengthened concrete subjected to chemical-freeze-thaw coupling erosion.

The corrosion resistance of FRP-reinforced ordinary concrete members under the combined action of harsh environments (i.e., alkaline or acidic solutions, salt solutions) and freeze-thaw cycles is still unclear. To study the mechanical and apparent deterioration of carbon/basalt/glass/aramid fiber cloth reinforced concrete under chemical and freeze-thaw coupling. Plain concrete blocks and FRP-bonded concrete blocks were fabricated. The tensile properties of the FRP sheet and epoxy resin sheet before and after chemical freezing, the compressive strength of the FRP reinforced test block, and the bending capacity of the prismatic test block pasted with FRP on the prefabricated crack side were tested. The deterioration mechanism of the test block was analyzed through the change of surface photos. Based on the experimental data, the Lam-Teng constitutive model of concrete reinforced by alkali-freeze coupling FRP is modified. The results indicate that, in terms of apparent properties, with the increase in the duration of chemical freeze-thaw erosion, the surface of epoxy resin sheets exhibits an increase in pores, along with the emergence of small cracks and wrinkles. The texture of FRP sheets becomes blurred, and cracks and wrinkles appear on the surface. In terms of failure modes, as the number of chemical coupling erosion cycles increases, the location of failure in epoxy resin sheets becomes uncertain, and the failure plane tilts towards the direction of the applied load. The failure mode of FRP sheets remains unchanged. However, the bonding strength between FRP sheets and concrete decreases, resulting in a weakened reinforcement effect. In terms of mechanical properties, FRP sheets undergo the most severe degradation in the coupled environment of acid freeze-thaw cycles. Among them, GFRP experiences the largest degradation in tensile strength, reaching up to 30.17%. In terms of tensile performance, the sheets rank from highest to lowest as follows: CFRP, BFRP, AFRP, and GFRP.As the duration of chemical freeze-coupled erosion increases, the loss rate of compressive strength for specimens bonded with CFRP is the smallest (9.62% in salt freeze-thaw environment), while the loss rate of bearing capacity is higher for specimens reinforced with GFRP (33.8% in acid freeze-thaw environment). In contrast, the loss rate of bearing capacity is lower for specimens reinforced with CFRP (13.6% in salt freeze-thaw environment), but still higher for specimens reinforced with GFRP (25.8% in acid freeze-thaw environment).

Experimental investigation of the polymer-metal hybrids interfacial bonding fabricated by fused deposition modeling

In this paper, the fabrication of polymer-metal hybrids by fused deposition modeling was evaluated. 6061 aluminum alloy and polylactic acid were used in the manufacturing process. Also, to strengthen the bonding between the metal and polymer components, a two-component epoxy adhesive was used. The pull-off adhesion test was performed to evaluate the interfacial bonding strength of the specimens. In this study, the effect of bed temperature, print speed, printer nozzle diameter, and aluminum sheet surface roughness on the bond strength of polymer-metal hybrids has been investigated. The results showed that increasing the bed temperature, and aluminum sheet surface roughness, and also decreasing the print speed led to increase the bond strength of polymer-metal hybrids. Finally, by using the experimental data, an optimal specimen was produced. The interfacial bonding strength of the optimal specimen is about 64% stronger than the initial specimen.

A comparative study of mass balance in the Lambert Glacier and Amery Ice Shelf along the Chinese inland traverse during 2019–2023 using altimetry, gravity, and in-situ observations

Abstract. The new photon-counting laser altimetry satellite ICESat-2 was successfully launched on September 15, 2018 with an unprecedented ice surface elevation measurement accuracy of 2–4 cm. It is meaningful for accurately estimating volumetric changes in the Antarctic Ice Sheet. Cross-validation of different types of data, especially comparison with in-situ data, is important for the ice sheet mass balance results of a new satellite. This paper proposes an elevation-difference method of grid elevation change rate model, based on ICESat-2 ATL11 elevation time series data, to distinguish the linear change trend of ice sheet surface elevation from the elevation change resulting from periodic precipitation. In order to compare the estimated elevation-change rate with the flux computed from in-situ snow stake velocity measurements and GRACE-FO gravity survey data, we made corrections for firn air content, elastic, and glacier isostatic adjustment. Based on the ATL11 data from 2019 to 2023, our results show that the ice sheet change in Basin 11 along the CHINARE traverse is from ~0.019 m yr−1 to ~0.121 m yr−1, and the mass balance in the upstream of the traverse in Basin 11 is ~1.9±0.2 Gt yr−1. It is comparable to ~2.4±1.2 Gt yr−1 from GRACE-FO during the same time period. Furthermore, the flux across traverse-11.9±1.1 Gt yr−1 is comparable to that of ~-9.7±0.9 Gt yr−1 across the same flux gate during 1997–2009 which is calculated based on GNSS-derived ice velocity observations, considering the time period difference and uncertainties.

Influence of Supraglacial Lakes on Accuracy of Inversion of Greenland Ice Sheet Surface Melt Data in Different Passive Microwave Bands

The occurrence of Supraglacial Lakes (SGLs) may influence the signals acquired with microwave radiometers, which may result in a degree of uncertainty when employing microwave radiometer data for the detection of surface melt. Accurate monitoring of surface melting requires a reasonable assessment of this uncertainty. However, there is a scarcity of research in this field. Therefore, in this study, we computed surface melt in the vicinity of Automatic Weather Stations (AWSs) by employing Defense Meteorological Satellite Program (DMSP) Ka-band data and Soil Moisture and Ocean Salinity (SMOS) satellite L-band data and extracted SGL pixels by utilizing Sentinel-2 data. A comparison between surface melt results derived from AWS air temperature estimates and those obtained with remote sensing inversion in the two different bands was conducted for sites below the mean snowline elevation during the summers of 2016 to 2020. Compared with sites with no SGLs, the commission error (CO) of DMSP morning and evening data at sites where these water bodies were present increased by 36% and 30%, respectively, and the number of days with CO increased by 12 and 3 days, respectively. The omission error (OM) of SMOS morning and evening data increased by 33% and 32%, respectively, and the number of days with OM increased by 17 and 21 days, respectively. Identifying the source of error is a prerequisite for the improvement of surface melt algorithms, for which this study provides a basis.

Comparison of the hydrogen damage of different rolling surfaces of TC4 Ti alloy sheet

Abstract The microstructure of three rolling surfaces of TC4 sheet is different, and their resistance ability to hydrogen damage lacks systematic research. Thus, the hydrogen damage behavior of TC4 rolling sheet was investigated in this paper. The hydrogen diffusion law along different rolling directions and the precipitation of hydrides on different rolling surfaces were compared. It is found that the shape and distribution of α and β phases are changed under the action of extrusion force during the rolling process, and they are arranged in striped shape on the R-N surface along the R direction, and the diffusion of hydrogen along the R direction is faster due to the existence of continuous β phases as hydrogen diffusion channels, resulting in the more serious hydrogen damage. Besides the hydrides mainly deposited at the α and β phase boundaries, the hydrides precipitated in the interior of α phases on the R-N surface are more than that on the R-T surface due to the different distribution state of β phases.

Flutter characteristics of a sheet with an elastic support in three-dimensional uniform flow

In the manufacturing processes of thin flexible plates (sheets) such as polarizing films, the flutter can be caused to the sheets due to the interaction between the motion of the sheets and fluid flow. Then, the flutter can cause serious damage to the sheets, leading to the wrinkles and scratches. Thus, it is crucial to investigate a detailed characteristics and excitation mechanism of the flutter. In the present study, a detailed flutter characteristics and excitation mechanism of a rectangular sheet with an elastic support is investigated. The elastic support is implemented using a fine flexible wire. The influence of bending stiffness of the support section on the flutter velocity and frequency is clarified through wind-tunnel experiments and numerical analysis. Moreover, the work done by the fluid force on the sheet surface was determined.The flutter velocity and frequency drastically decrease owing to decrease in bending stiffness of the support section regardless of the aspect and mass ratio. Then, the positive work region around the leading edge of the sheet expands owing to the large-amplitude oscillation around the leading edge. The expansion of positive work region owing to a large-amplitude oscillation around the leading edge of the sheet destabilizes the system.

Fatigue behaviour and life prediction of self-piercing riveted joints in DP590/AA5754 dissimilar sheets

This paper investigates the fatigue properties of self-piercing riveted joints made by DP590 steel and AA5754 aluminium alloy. The fatigue failure mechanism and fatigue fretting mechanism of the joint were well revealed by analysing the microstructure features of fracture surfaces of sheets and rivets as well as viewing and measuring the distribution and chemical composition of fretting debris. The fatigue life of the joint was also predicted based on the stress intensity factor of the kinked crack of the lower sheet. The results confirmed that two failure modes occurred during fatigue: lower sheet fracture and rivet fracture. During the fatigue failure, cracks appeared in both the lower sheet and the rivets, indicating a competitive relationship between the propagation of cracks in the lower sheet and the rivets. In the range of 40 % and 50 % load level, fatigue crack propagation of the lower sheet is dominant and fracture failure of the lower sheet occurs. Rivet fatigue crack propagation has a significant advantage in the 60 % load range and rivet fracture failure often occurs. It was found that the fatigue failure of the lower sheet is mainly influenced by the main crack, which produces two different morphological sections. Fretting wear of the contact surface was the source of crack initiation, and the fretting debris promoted crack initiation and propagation. Cracks propagate along the width and thickness of the plate, as well as the thickness of the rivet neck. The stress intensity factor range can properly predict the fatigue life of joints.

Modeling, validation, and optimization of a rotating advanced oxidation contactor equipped with TiO2-zeolite composite sheets for sulfamethazine removal

The necessity to remove antibiotic residues such as sulfamethazine from veterinary/hospital wastewater is evident due to their widespread existence, challenges in treatment, and potential harm in aquatic ecosystems. This study focused on modeling, validating, and optimizing the removal of sulfamethazine (SMT) using two lab-scale rotating advanced oxidation contactor (RAOC) systems equipped with TiO2-zeolite composite sheets. Four key parameters—temperature, UV intensity, rotation speed, and sheet area by tank volume (A/V)—were investigated to understand their individual effects and interactions using the drum-RAOC system. The adsorption and decomposition processes of the RAOC systems were separately studied. In terms of the adsorption process, A/V was found to be the primary parameter influencing RAOC performance, with significant interaction observed between temperature and A/V. For the decomposition process, A/V and UV intensity were identified as the dominant parameters, with interactions affecting photocatalysis performance. Kinetic fitting was used to explore the underlying mechanisms, and liquid film thickness on the sheet surface was employed to support the explanations. Furthermore, validation experiments conducted using the disk-RAOC system confirmed the accuracy and applicability of these models. Through comprehensive optimization, the optimal parameter set was determined: temperature of 20°C, rotation speed of 5rpm, UV intensity of 1.5mW/cm2, and A/V of 200 cm2/L. Additionally, the current findings were compared with previous studies to illustrate the efficiency of RAOC systems. These results provide valuable guidelines for designing and operating RAOC systems and serve as a reference for balancing performance and consumption in immobilized photocatalysis systems

A dual-purpose photocatalytic reaction for hydrogen evolution and simultaneous organic pollutant degradation of V2O5/Ppy based composite photocatalyst

The present work reports for the facile synthesis of novel vanadium oxide/polypyrrole (V2O5/Ppy) nanohybrids using various loadings of the V2O5. This novel hybrid photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman, UV-Visible absorption spectra (UV-Vis), photoluminescence spectra (PLS) and N2 adsorption-desorption analysis. XRD and TEM results suggest that V2O5 with individual spherical shaped nanoparticles of around 20-25 nm, which is uniformly wrapped on the surface of the Ppy sheets. A significant reduction in the bad gap energy (3.06-2.13 eV) and prevent the electron-hole recombination process was examined by UV and PL studies. The photocatalytic degradation efficiency was carried out for Reactive Black 31 (RB 31) and 4-chlorophenol (4-CP) dyes under visible light. The results illustrate that the optimal hybrid catalyst could reach 99% of removal efficiency towards RB31 with visible light irradiation for 60 min. Moreover, the catalyst show high TOC efficiency (88 %) high apparent constant (0.9189 min−1), and good stability with multiple cycle experiments. The improved photocatalytic mechanism was also discussed in detail. In comparison to V2O5 (425 μmol−1h−1 of H2) and PPy (151 μmol−1h−1 of H2), the optimised composite, 15 wt% V2O5 incorporated PPy showed a remarkable production rate under visible light (2255 μmol−1h−1 of H2).

Rational sonochemical engineering of Ag2CrO4/g-C3N4 heterojunction for eradicating RhB dye under full broad spectrum

In this novel research, S-scheme Ag2CrO4/g-C3N4 heterojunctions were generated by sonochemical hybridization of different compositions of Ag2CrO4 nanoparticles [EVB=+2.21 eV] and g-C3N4 sheets [ECB=-1.3 eV] for destructing RhB dye under artificial solar radiation. The as-synthesized nanocomposites were subjected to X-ray diffraction [XRD], diffuse reflectance spectrum [DRS], X-ray photoelectron spectroscopy [XPS], N2-adsorption-desorption isotherm, photoluminescence [PL] and high resolution transmission electron microscope [HRTEM] analysis to explore the interfacial interactions between g-C3N4 sheets and Ag2CrO4 nanoparticles. Spherical Ag2CrO4 nanoparticles deposited homogeneously on the wrinkles points of g-C3N4 sheets at nearly equidistant from each other facilitating the uniform absorption of solar radiations. The absorbability of solar radiations was enhanced by introducing 20 wt % Ag2CrO4 on g-C3N4 sheets. The surface area of g-C3N4 sheets was reduced from 37.5 to 16.4 m2/g and PL signal intensity diminished by 80 % implying the successful interfacial interaction between Ag2CrO4 nanoparticles and g-C3N4 sheets. The photocatalytic performance of heterojunctions containing 20% Ag2CrO4 and 80 % g-C3N4 destructed 96 % of RhB dye compared with 60 and 33 % removal on the surface of pristine g-C3N4 sheets and Ag2CrO4, respectively. Benzoquinone and ammonium oxalate are strongly scavenged the dye decomposition revealing the strong influence of valence band holes of Ag2CrO4 and superoxide radicals in destructing RhB dye under solar radiations. S-scheme charge transportation mechanism was suggested rather than type II heterojunction on the light of scavenger trapping experiments results and PL spectrum of terephthalic acid. Overall, this research work illustrated the manipulation of novel S-scheme heterojunction with efficient redox power for destructing various organic pollutants persisted in water resources.

Improved Near-Resonant Two Photon Absorption of α-MnO2 Nanowires Surface Functionalized Reduced Graphene Oxide Sheets

The versatile study of graphene derivatives has resurgence of interest on understanding its nonlinear optical response at different nanoscales. Nanostructured manganese dioxide: reduced graphene oxide (MnO2: rGO) hybrids were synthesized by reduction method by varying the content of rGO (5, 10, 15 & 20wt%). X-ray Photoelectron Spectroscopy studies confirmed the surface functionalization of MnO2 on rGO. Field Emission Scanning Electron Microscopy (FESEM) and High-Resolution Tunnelling Electron Microscopy (HRTEM) witness that with respect to the content of rGO, the morphology of MnO2 varies radically from clusters to nanorods to nanowires over the surface of rGO sheets. Ground state absorption spectra of the hybrids have absorption edge at 268nm corresponding to combined metal oxide charge transfer between rGO (π-π⁎ transition of C=C and n-π transition of C-O bonds) and MnO2 (d-d transition). Moreover, hierarchical MnO2 nanowire network resided on 2D rGO sheets involves broad absorption at the visible spectral domain due to polaron transition as well the localization of π- π⁎ transited electrons that facilitates the probability of occurrence of excited state absorption. Intensity dependent open aperture Z-scan technique of the prepared hybrids using Q-switched Nd: YAG 532nm nanopulsed laser reveals unusual transitions and enhanced nonlinear absorption. MnO2:(5wt%) rGO shows saturable absorption (SA) at low intensity and changeover dynamically to reverse saturable absorption (RSA) at higher intensity. MnO2:(10 & 15wt%) rGO exposes coupled nonlinear absorption (SA + RSA) owing to the combined effect of graphene (π-states) and MnO2 (σ-states). MnO2:(20wt%) rGO exhibits a stronger RSA ascribed to sequential two photon absorption. The third-order nonlinear absorption coefficient and limiting threshold of MnO2: rGO (20wt%) are 4.04 ×10-10m/W and 0.84 ×1012W/m2, which shows five-fold increase compared to bare rGO and MnO2. The obtained results propose that the optical nonlinearity of MnO2 nanowires surface functionalized rGO sheets can significantly be tuned to meet the requirements for fabricating laser safety devices.

Introducing a novel sheet test specimen for biaxial stretching under uniaxial loading

This paper introduces a novel sheet test specimen that plastically deforms under biaxial stretching when subjected to uniaxial loading in conventional testing machines. The specimen was designed using finite element simulation and consists of a two-dimensional reticular structure with interconnected arms in the form of triangles that converge at the center and are connected to full-width sheets at the specimen's ends. Accumulation of damage at the center is ensured through spherical cups that are milled at opposite sheet surfaces. Experimental strain loading paths obtained by digital image correlation confirm the capability of the novel sheet test specimen to provide biaxial stretching strain paths. This is achieved under friction-independent conditions and without requiring complicated multiaxial setups and machines, provided appropriate values of the inner and outer angles of the interconnected arms are used.

Effect of CaO in magnesia coating on Mg2SiO4 layer formation on the surface of grain-oriented electrical steel

Mg2SiO4 layer formed by the reaction between magnesia separator coating and the oxide layer on the surface of grain-oriented electrical steel sheets plays important roles for magnetic performances of grain-oriented electrical steel. High-quality Mg2SiO4 layer is the key factor for the high-quality grain-oriented electrical steel production. This article makes investigations on Mg2SiO4 layers formed with different CaO content in magnesia coating after the final box annealing treatment. And the suitable CaO content which promote the formation of excellent Mg2SiO4 layer were summarized. All these studies provide theoretical and data support for the high-quality grain-oriented electrical steel production on site.

Alpine topography of the Gamburtsev Subglacial Mountains, Antarctica, mapped from ice sheet surface morphology

Abstract. Landscapes buried beneath the Antarctic Ice Sheet preserve information about the geologic and geomorphic evolution of the continent both before and during the wide-scale glaciation that began roughly 34×106 years ago. Since the inception of this ice sheet, some areas have remained cold-based and non-erosive, preserving ancient landscapes remarkably intact. The Gamburtsev Subglacial Mountains in central East Antarctica are one such landscape, maintaining evidence of tectonic, fluvial and glacial controls on their distinctly alpine morphology. The central Gamburtsev Mountains have previously been surveyed using airborne ice-penetrating radar; however, many questions remain as to their evolution and their influence on the East Antarctic Ice Sheet, including where in the region to drill for a 1.5×106 year-long “oldest-ice” core. Here, we derive new maps of the planform geometry of the Gamburtsev Subglacial Mountains from satellite remote sensing datasets of the ice sheet surface, based on the relationship between bed roughness and ice surface morphology. Automated and manual approaches to mapping were tested and validated against existing radar data and elevation models. Manual mapping was more effective than automated approaches at reproducing bed features observed in radar data, but a hybrid approach is suggested for future work. The maps produced here show the detail of mountain ridges and valleys on wavelengths significantly smaller than the spacing of existing radar flightlines, and mapping has extended well beyond the confines of existing radar surveys. Morphometric analysis of the mapped landscape reveals that it constitutes a preserved (>34 Ma) dendritic valley network, with some evidence for modification by topographically confined glaciation prior to ice sheet inception. The planform geometry of the landscape is a significant control on locations of basal melting, subglacial hydrological flows and the stability of the ice sheet over time, so the maps presented here may help to guide decisions about where to search for oldest ice.

Facile synthesis of rGO nanosheet encapsulated Ni2V2O7 nanorods for energy storage applications

The less emission, environmental friendliness and less hazardous energy storage materials are most impotent to the clean energy system. Here we synthesis rGO anchored nickel vanadate nanorods for supercapacitor application. As a result, the Ni2V2O7 and rGO@Ni2V2O7 nanomaterials show a monoclinic structure from the XRD pattern. The vibrational of V–O–V and Ni–O along with the main peak of carbon materials indicates the rGO anchoring with Ni2V2O7 in the FTIR and Raman spectra. The SEM and TEM images illustrate a rod shaped Ni2V2O7 was attached over the rGO sheet surface. From the BET analysis, the rGO@Ni2V2O7 sample has a higher surface area than the Ni2V2O7 electrode. Further, the supercapacitor application of Ni2V2O7 and rGO@Ni2V2O7 electrodes shows 318 F/g and 624 F/g at 1 A/g capacitance values. Although, the rGO@Ni2V2O7 electrode shows higher power (771 W/kg) and energy density (22.28 Wh/kg) values than the NiV2O7 electrode. Moreover, the rGO@Ni2V2O7 exhibits a 95% of capacitance retention value even at the 1000th cycle. Moreover, the prepared rGO@Ni2V2O7 has less Rct value of 4.72 Ω) than the Ni2V2O7 electrode (9.86 Ω). The attachment of rGO can provide a higher surface area, higher conductivity and lower resistivity to the Ni2V2O7 electrode. According to these results, the rGO@Ni2V2O7 electrode is the more suitable for supercapacitor electrodes.

Experimental Investigation of Load-Bearing Capacity in EN AW-2024-T3 Aluminum Alloy Sheets Strengthened by SPIF-Fabricated Stiffening Rib.

The aluminum strength-to-weight ratio has become a highly significant factor in industrial applications. Placing stiffening ribs along the surface can significantly improve the panel's resistance to bending and compression in aluminum alloys. This study used single-point incremental forming (SPIF) to fabricate stiffening ribs for 1 mm and 3 mm thick aluminum alloy EN AW-2024-T3 sheets. A universal compression machine was used to investigate sheet deformation. The resulting deformation was examined using non-contact digital image correlation (DIC) based on several high-resolution cameras. The results showed that deformation progressively escalated from the edges toward the center, and the highest buckling values were confined within the non-strengthened area. Specimens with a larger thickness (3 mm) showed better effectiveness against buckling and bending for each applied load: 8 kN or 10 kN. Additionally, the displacement from the sheet surface decreased by 60% for sheets 3 mm thick and by half for sheets 1 mm thick, which indicated that thicker sheets could resist deformation better.

The Effect of Physically Based Ice Radiative Processes on Greenland Ice Sheet Albedo and Surface Mass Balance in E3SM

AbstractA significant portion of surface melt on the Greenland Ice Sheet (GrIS) is due to dark ice regions in the ablation zone, where solar absorption is influenced by the physical properties of the ice, light absorbing constituents (LACs), and the overlying crustal surface or melt ponds. Earth system models (ESMs) typically prescribe the albedo of ice surfaces as a constant value in the visible and near‐infrared spectral regions. This work advances ESM ice radiative transfer modeling by (a) incorporating a physically based radiative transfer model (SNow, ICe and Aerosol Radiation model Adding‐Doubling Version 4; SNICAR‐ADv4) into the Energy Exascale Earth System Model (E3SM), (b) determining spatially and temporally varying bare ice physical properties over the GrIS ablation zone from satellite observations to inform SNICAR‐ADv4, and (c) assessing the impacts on simulated GrIS albedo and surface mass balance associated with modeling of more realistic bare ice albedo. GrIS‐wide bare ice albedo in E3SMv2 is overestimated by ∼4% in the visible and ∼7% in the near‐infrared wavelengths compared to the Moderate Resolution Imaging Spectroradiometer. Our bare ice physical property retrieval method found that LACs, ice crustal surfaces, and melt ponds reduce visible albedo by 30% in the bare ice region of the GrIS ablation zone. The realistic bare ice albedo reduces surface mass balance by ∼145 Gt, or 0.4 mm of sea‐level equivalent between 2000 and 2021 compared to the default E3SM. This work highlights the importance of simulating bare ice albedo accurately and realistically to improve our ability to quantify changes in the GrIS surface mass and radiative energy budgets.

Structure and properties of self-assembled graphene oxide–detonation nanodiamond composites

The properties of graphene oxide–detonation nanodiamond composites obtained as a result of heterocoagulation of graphene oxide and hydrogenated detonation nanodiamonds in aqueous mixtures were studied. The resulting composites with different proportions of graphene oxide and detonation nanodiamond were subjected to drying and subsequent heat treatment in a vacuum, converting graphene oxide into graphene. The structure of the composites was studied using electron microscopy and Raman spectroscopy. The specific surface area and porosity of the obtained samples were studied by analyzing nitrogen adsorption isotherms. A model for the composite formation and a possible technology for producing a material based on it with different specific surface area values and pore structure are proposed. It is shown, that the largest possible specific surface area of two-component structures of the «DND/GO» type does not exceed 500 m2·g−1. It was also concluded that it is necessary to achieve a uniform distribution of detonation nanodiamond particles over the surface of graphene sheets.

Graphene oxide/ε-poly-L-lysine self-assembled functionalized coatings improve the biocompatibility and antibacterial properties of titanium implants.

The construction of an antibacterial biological coating on titanium surface plays an important role in the long-term stability of oral implant restoration. Graphene oxide (GO) has been widely studied because of its excellent antibacterial properties and osteogenic activity. However, striking a balance between its biological toxicity and antibacterial properties remains a significant challenge with GO. ε-poly-L-lysine (PLL) has broad-spectrum antibacterial activity and ultra-high safety performance. Using Layer-by-layer self-assembly technology (LBL), different layers of PLL/GO coatings and GO self-assembly coatings were assembled on the surface of titanium sheet. The materials were characterized using scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle test. The antibacterial properties of Porphyromonas gingivalis (P.g.) were analyzed through SEM, coated plate experiment, and inhibition zone experiment. CCK-8 was used to determine the cytotoxicity of the material to MC3T3 cells, and zebrafish larvae and embryos were used to determine the developmental toxicity and inflammatory effects of the material. The results show that the combined assembly of 20 layers of GO and PLL exhibits good antibacterial properties and no biological toxicity, suggesting a potential application for a titanium-based implant modification scheme.