Protective Layer Research Articles

Sustainable Grease Lubrication Induced by Graphene Oxide and LiFePO4

This study investigates the possibility of modifying lubricating greases by 2D graphene oxide (GO) and lithium iron phosphate (LiFePO4) to enhance their tribological performance. GO's layered structure plays a crucial role in reducing friction by facilitating easy sliding between rubbing surfaces, making it an effective solid lubricant. The impact of these additives on friction reduction, wear resistance, and the tribolayer formation ability is evaluated by ball‐on‐disc tribometry with an emphasis on durability and sustainability. Comparative results reveal that unmodified greases exhibit a high susceptibility to wear, including oxide formation and severe plastic deformation. In contrast, greases with GO show a notable reduction in friction, while the addition of LiFePO4 contributes to the formation of a continuous protective layer that substantially reduces abrasive wear. The combination of GO and LiFePO4 results in a homogeneous, durable tribofilm that effectively protects surfaces against severe wear providing long‐term friction stability. Although lab‐scale LiFePO4 is used, the findings suggest a great potential for extending the useful life of recycled LiFePO4 from lithium‐ion batteries, similar to commercial LiFePO4 thus confirming significant improvements in the grease performance but also highlighting the potential to advance toward more sustainable solutions in industrial applications and electric vehicles.

Travel Medicine for Immunocompromised Travelers: An Essential Layer of Protection

Travel Medicine for Immunocompromised Travelers: An Essential Layer of Protection

Study on the Dynamic Evolution of Mining-Induced Stress and Displacement in the Floor Coal-Rock Induced by Protective Layer Mining

Protective layer mining is the most effective means to prevent and control coal and gas outbursts. In order to deeply understand the dynamic evolution law of mining stress and displacement of the bottom plate coal rock body in the process of protective layer mining, the effects of upper protective layer mining on stress variation and displacement deformation in the underlying coal seam were studied using the similar experiment and FLAC3D simulations. The results reveal that mining in the 82# coal seam notably alleviates pressure in the 9# coal seam below, with an average relief rate of 86.2%, demonstrated by the maximal strike expansion deformation rate of 11.3‰ in the 9# coal seam post-mining. Stress monitoring data indicates a stress concentration zone within 32 m ahead of the working face, and a pressure relief zone within 51 m behind it. The research provides a scientific foundation for pressure-relief gas extraction techniques, affirming the substantial impact of upper protective layer mining on alleviating pressure in underlying coal seams, enhancing safety, and optimizing mining efficiency.

What to do with your maintenance records for protection layers?

AbstractCollecting and analyzing operation and maintenance data is essential to process safety. The analysis aims to demonstrate that what is installed in the field achieves the required performance so that adjustments can be made if the required performance is not met. Very large organizations routinely have data collection systems and resources for data analysis. Midsized and smaller organizations collect the same data in various ways but often need help to analyze it. This paper presents examples of American Petroleum Institute (API) 754 Tier 3 and 4 metrics related to protection layers and how to use available plant data to support their analysis.

Functional organic 7,7,8,8‐tetracyanoquinodimethane artificial layers for the dendrite suppressed lithium metal anodes

AbstractThe large‐scale industrialization of lithium metal (Li), as a potential anode for a high energy density energy storage system, has been hindered by dendrite growth. The construction of an artificial solid electrolyte interphase layer featuring high ionic and low electronic conductivity has been verified to be a high‐performance strategy to confine the dendrite growth and promote the Li anode stability. Therefore, a functional organic protective layer is homogeneously deposited on the Li anode surface via an in situ chemical reaction between tetracyanoquinodimethane (TCNQ) and Li. The as‐synthesized Lin‐TCNQ organic film could efficiently trap non‐uniform Li deposition and restrain dendrite propagation. Particularly, an asymmetric M‐TCNQ‐Li|Cu cell with the Lin‐TCNQ layer breezed through a high Coulombic efficiency of 91.15% after 100 cycles at 1.0 mA cm−2. The M‐TCNQ‐Li|NCM622 cell delivered a high capacity of 143.40 mAh g−1 at 0.2 C and maintained a good cyclic stability of 110.44 mAh g−1 after 160 cycles. The analysis results of spectroscopic tests further demonstrate that the Lin‐TCNQ with the enhanced absorption energy is conducive to lithiophilicity and decreases the overpotential of Li deposition.

Dual Strategies of Na+ Electrolyte Additives and Dendrites Protective Ti3C2TX‐MXene/Zn Anode with 2D MXene Nanosheet Encased Niobium Pyrophosphate (NbP2O7) Composite Binder‐Free Cathode for Stable Zinc‐Ion Storage

AbstractZinc‐ion capacitors (ZICs) are promising next‐generation energy storage systems (ESS) owing to high safety, material abundance, environmental friendliness, and low cost; however, the energy density of ZICs must be improved to compete with lithium‐ion batteries (LIBs). Here, the study implements three strategies to enhance the electrochemical performance and manage dendritic growth on Zn anodes, including crafting a highly efficient redox electroactive niobium pyrophosphate (NbP2O7)/Ti3C2TX‐MXene binder‐free cathode, incorporating a NaClO4 additive electrolyte, and applying a protective Ti3C2TX‐MXene layer on Zn anode. The cathode facilitates rapid Zn2+ ion diffusion and a stable host structure. An electrostatic protection layer formed in additive electrolyte and MXene layers regulates the uniform distribution of the electric fields and supports the equalization of nucleation sites. These results are supported by density functional theory (DFT) calculations. The ZICs display an excellent specific capacitance (113.3 F g−1 at 1.5 A g−1) in aqueous additive electrolytes. The flexible solid‐state ZICs exhibits a volumetric capacitance of 865.05 mF cm−3, and an energy density of 0.347 mWh cm−3 at 2.29 mW cm−3 along with capacitance retention of >100% over 38 000 charge‐discharge cycles.

Gene Therapy for Inflammatory Cascade in Intrauterine Injury with Engineered Extracellular Vesicles Hybrid Snail Mucus-enhanced Adhesive Hydrogels.

Early hyper-inflammation caused by intrauterine injury triggered subsequent intrauterine adhesion (IUA). STAT1-mediated M1 macrophages are confirmed to secrete pro-inflammatory cytokines to accelerate inflammatory cascade and IUA formation by multi-omics analysis and experimental verification. However, clinically used hyaluronic acid (HA) hydrogels are prone to slip out of injury sites due to poor bio-adhesion properties. Therefore, there are still challenges in applying hydrogels for M1 macrophage intervention in IUA treatment. Herein, an engineered extracellular vesicles (EVs) hybrid snail mucus (SM)-enhanced adhesive hydrogels to improve bio-adhesion property is fabricated and M1 macrophage intervention through targeting delivery and STAT1 silencing is achieved. First, inspired by the high bio-adhesion capacity of SM, SM and gelatin methacrylate (GelMA) solution are mixed to construct GelMA/SM (GS) hydrogel. Then, folic acid-modified extracellular vesicles (FA-EVs) are synthesized for targeting the delivery of STAT1-siRNA. Upon injection of FA-EVs hybrid GS hydrogel into the uterine cavity, a protective hydrogel layer forms on the surface of injury sites and sustains the release of STAT1-siRNA-loaded FA-EVs to curtail M1 macrophages generation through inhibiting STAT1 phosphorylation, resulting in reduction of myofibroblasts activation and collagen deposition. In addition, the pregnancy rate and the number of fetuses in rats treated with this hydrogel were much higher than those in other groups, suggesting that the hydrogel could promote functional endometrial regeneration and restore fertility. Overall, this study presents a promising strategy for employing FA-EVs hybrid adhesive hydrogel with superior bio-adhesion properties and M1 macrophage targeting delivery for IUA treatment and uterus recovery.

Human-Centered Cybersecurity Revisited: From Enemies to Partners

Focusing on "enabling approaches" that treat humans as partners can add another layer of protection to our cybersecurity defenses.

Failure of the SRC under freeze- thaw cycles by the push-out tests

This paper explores the impact of freeze-thaw cycles, the thickness of the protective layer, embedment length, and volumetric hoop ratio on the bond performance at the SRC interface, assessed through freeze-thaw and push-out tests. Results from SEM indicated significant cracking in concrete exposed to freeze-thaw cycles, with an increase in both the number and diameter of pores. Despite significant damage to the concrete exterior, the interface exhibited considerably less deterioration. Following 200 freeze-thaw cycles, the specimens displayed a maximum crack depth of 2.3 mm and a porosity rate of 35.1 %. As the cycles progressed, the failure mode of specimens under push-out loading transitioned from splitting to interfacial shear failure. Notably, the length of cracks on the end surfaces was markedly reduced, and the majority of specimens exhibited minimal cracking on the side surfaces. Additionally, interfacial bond stress decreased progressively with the increasing number of cycles. The ultimate bond stress declined more rapidly than residual bond stress, with the rate of decrease stabilizing after surpassing 100 cycles. Enhancements in protective layer thickness, embedment length, and volumetric hoop ratio effectively mitigated the reductions in bond stress. Among these, the protective layer had the most significant impact, followed by the volumetric hoop ratio, while embedment length had the least influence. The study concludes with proposed formulas for calculating bond stress and slip eigenvalues after freeze-thaw cycles, integrating experimental results and theoretical analysis.

Rational design of α-MnO2@TiO2 composites for high-performance zinc ions batteries

Aqueous zinc ions batteries (AZIBs) have attracted widespread interest due to their remarkable energy density, non-toxicity, environmental friendliness and low cost. However, the application of MnO2 cathode materials for AZIBs is limited owing to the dissolution of Mn2+, structural collapse and intrinsic poor conductivity. Herein, α-MnO2@TiO2 composites were synthesized via simple hydrothermal and calcination approaches. Some smaller TiO2 were coated on the MnO2 nanorods to form the protective layer. The TiO2 protective layer not only prevents the dissolution of Mn2+ and structural collapse of MnO2, but also enhances the conductivity of the material due to the presence of Ti3+ defects, which increased electrode materials wettability, specific surface area and diffusion rate of Zn2+. In addition, the coating TiO2 causes surface adsorbed oxygen and surface binding defects in α-MnO2@TiO2, and increases surface reactivity and electrochemically active sites, which provides abundant channels and available insertion electrochemically active sites for H+/Zn2+ transport. As a result, α-MnO2@TiO2–2 delivers a high specific capacity of 182.90 mAh g−1 at 1 A g−1 after 600 cycles and outstanding rate capacity of 127.91 mAh g−1 at 5 A g−1. This work provides an idea for exploring high-performance cathode materials for AZIBs.

Inside Front Cover: Ostwald‐Ripening Induced Interfacial Protection Layer Boosts 1,000,000‐Cycled Hydronium‐Ion Battery

Inside Front Cover: Ostwald‐Ripening Induced Interfacial Protection Layer Boosts 1,000,000‐Cycled Hydronium‐Ion Battery

Inside Front Cover: Ostwald‐Ripening Induced Interfacial Protection Layer Boosts 1,000,000‐Cycled Hydronium‐Ion Battery

Inside Front Cover: Ostwald‐Ripening Induced Interfacial Protection Layer Boosts 1,000,000‐Cycled Hydronium‐Ion Battery

Effect of Protective Coating Layer and Overlapping Factor on the Microstructure and Mechanical Properties of Rene-80 Ni-Based Superalloy in Laser Shock Peening Process

Effect of Protective Coating Layer and Overlapping Factor on the Microstructure and Mechanical Properties of Rene-80 Ni-Based Superalloy in Laser Shock Peening Process

Dendrite-Free Lithium Batteries Enabled by an Artificial High-Dielectric Biopolymer Interface Layer.

Lithium (Li) metal batteries face challenges, such as dendrite growth and electrolyte interface instability. Artificial interface layers alleviate these issues. Here, cellulose nanocrystal (CNC) nanomembranes, with excellent mechanical properties and high specific surface areas, combine with polyvinylidene-hexafluoropropylene (PVDF-HFP) porous membranes to form an artificial solid electrolyte interphase (SEI) layer. The porous structure of PVDF-HFP equalizes the electric field near metallic lithium surfaces. The high mechanical modulus of CNC (6.2 GPa) effectively inhibits dendrite growth, ensures the uniform flow of lithium ions to the lithium metal electrode, and inhibits the growth of lithium dendrites during cycling. The synergy of high polarity β-phase poly(vinylidene fluoride) (PVDF) and CNC provides over 1000 h of stability for Li//Li batteries. Moreover, Li//LiFePO4 (LFP) full cells with this artificial protective layer perform well at 5 C, showcasing the potential of this film in lithium metal batteries.

Hazard Identification of Well Test Operation in Drilling and Production Offshore Platform by HAZID

A significant portion of energy resources has been discovered in offshore sectors, leading to a continuous increase in the volume of activities and operations. Once a well is drilled and fluid extraction begins, all the reservoir parameters, start to change. well test operation is one of the most crucial tools for engineers to comprehend the behavior and parameters of hydrocarbon reservoirs. In this study, the hazards associated with the well test operations has been identified by using HAZID technique. A total of 189 risks were identified in the initial risk assessment, with 35 categorized as low risk, 88 as medium risk, and 66 as high risk and after implementing protection layers in the secondary risk assessment, the number of low risks incidents increased, while medium and high-risk incidents were reduced significantly. Most of the risks identified are associated with loading operations and sea transportation from the port to the drilling rig. Given that loading and unloading operations are among the most frequently repeated activities in well testing operations, it is determined that they play a critical role in the overall risk profile

Regulating the Helmholtz plane by trace ionic liquid additive for advanced Al-air battery

Al-air batteries (AABs) are the next generation of alternative energy sources due to their high theoretical energy density, low cost, and environmental friendliness. Researchers have been interested in AABs with stable discharge in alkaline solution, long discharge time, and high conductivity. However, the uncontrolled self-corrosion of the Al anode and the severe hydrogen evolution reaction in alkaline electrolytes have been two major drawbacks hindering the commercial development of AABs. These shortcomings reduce the Al anode's utilization and significantly shorten the battery's service life. Herein, the Helmholtz plane structure was reconstructed using an ionic liquid additive called 1-aminopropyl-3-methylimidazolium bromide (AMIB) to regulate the electrochemical interface between the electrolyte and the Al anode. Electrochemical tests found that when 3 mM AMIB was added, the corrosion inhibition efficiency could reach up to 60 %. Further surface analysis and theoretical calculations showed that AMIB can form a dense and uniform protective layer on the surface of the Al anode substrate, which reduces the anode corrosion, lowers the active centers for hydrogen evolution on the Al surface, and reduces the hydrogen evolution rate. The full-cell studies found that the specific capacity of the cell increased from 1227 to 2564 mAh g−1, the energy density increased from 1546 to 3359 Wh kg−1, and the Al anode utilization increased from 41.2 % to 86.1 % as the AMIB addition to the alkaline electrolyte risen from 0 to 3 mM. This method of electrolyte regulation provides an efficient strategy for the commercial development of AABs.

Long‐term Durability of Seawater Electrolysis for Hydrogen: From Catalysts to Systems

AbstractDirect electrochemical seawater splitting is a renewable, scalable, and potentially economic approach for green hydrogen production in environments where ultra‐pure water is not readily available. However, issues related to low durability caused by complex ions in seawater pose great challenges for its industrialization. In this review, a mechanistic analysis of durability issues of electrolytic seawater splitting is discussed. We critically analyze the development of seawater electrolysis and identify the durability challenges at both the anode and cathode. Particular emphasis is given to elucidating rational strategies for designing electrocatalysts/electrodes/interfaces with long lifetimes in realistic seawater including inducing passivating anion layers, preferential OH−adsorption, employing anti‐corrosion materials, fabricating protective layers, immobilizing Cl− on the surface of electrocatalysts, tailoring Cl− adsorption sites, inhibition of OH− binding to Mg2+ and Ca2+, inhibition of Mg and Ca hydroxide precipitation adherence, and co‐electrosynthesis of nano‐sized Mg hydroxides. Synthesis methods of electrocatalysts/electrodes and innovations in electrolyzer are also discussed. Furthermore, the prospects for developing seawater splitting technologies for clean hydrogen generation are summarized. We found that researchers have rethought the role of Cl− ions, as well as more attention to cathodic reaction and electrolyzers, which is conducive to accelerate the commercialization of seawater electrolysis.

Corrosion study of cola soft drink cans

The study of corrosion in aluminium packaging is fundamental to ensuring the quality and safety of the product. The varnish layer present on metal packaging aims to minimize any interaction between the food or drink and the metal, as well as minimizing the corrosion process. The acidic nature of soft drinks, as well as the ions present in solution, such as phosphates, benzoates or chlorides, play a strong role in the oxidative process of aluminum. This study evaluated the corrosion of the body of aluminum cola cans. The beverage was first characterized and the results obtained were: pH =2.5; 7.5 oBrix; chloride concentration of 0.17g/L, acidity 0.17 %m/m; density 1.04 g/mL and concentration of reducing sugars was 11.3 %m/m. The corrosion of aluminum in model solutions with different concentrations of citric acid and NaCl was studied via linear polarization for samples with and without varnish. The statistical analysis carried out, via factorial design 23 with a triplicate at the center point, showed that the corrosion rate (CR) of the sample with varnish was significantly influenced by temperatures above 45 oC in the range of chlorides studied. On the other hand, the CR of the sample without varnish was strongly influenced by the combination of high temperatures and high chloride concentrations. Removing the varnish resulted in a higher activation energy (AE = 67.48 kJ/mol) when removed with acetone and then polished with sandpaper compared to the sample with varnish (AE = 88.92 kJ/mol). From a kinetic point of view, this showed the protective effect of this layer and its effectiveness against corrosion. The ΔHo and ΔGo activation parameters of the process were positive, showing that corrosion is an endothermic process with increased disorder when the varnish is removed, respectively. It is therefore important to buy the product with the packaging in good condition to guarantee the integrity of the protective layer and its quality, since oxidation of the aluminum can lead to products that compromise the quality of the food or drink.

Corrosion inhibition performance of protein derived carbon quantum dots as corrosion inhibitors on low carbon steel in sulfuric acid solution

Protein derived carbon quantum dots (PCQDs) were successfully fabricated via a hydrothermal method with shrimp meat as the precursor. Subsequently, their corrosion-inhibiting performance on mild steel (L-steel) in a 0.5 mol/L H2SO4 solution was evaluated. Electrochemical impedance spectroscopy (EIS) tests demonstrated that at a concentration of 250 mg/L, the corrosion inhibition efficiency of PCQDs exceeded 90 %. Potentiodynamic polarization (PDP) tests indicated that when the concentration of PCQDs reached 500 mg/L, the corrosion inhibition efficiency was as high as 97.45 %. Comprehensive characterizations of the PCQDs, including X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy (UV–Vis), verified the existence of functional groups such as carboxyl, hydroxyl, and aromatic rings within the PCQDs. These groups are conducive to forming a strong adsorption force on the surface of L-steel and creating a protective layer. Surface morphology analyses carried out by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the surface of L-steel treated with PCQDs was significantly smoother in comparison to untreated samples exposed to acidic conditions. Adsorption studies disclosed a mixed physical and chemical adsorption behavior, and theoretical calculations showed that the N and S atoms in PCQDs preferentially adsorb in a parallel direction. The addition of PCQDs led to a reduction in the diffusion coefficient, indicating that the diffusion of corrosive ions was effectively hindered. The distribution function of PCQDs was 3.48 Å, which suggested that the chemisorption mechanism played a dominant role in the inhibition process.

Inflammasome activation links enteric Salmonella Typhimurium infection to a rapid, cytokine-dependent increase in intestinal mucin release

ABSTRACT The host restricts Salmonella enterica serovar Typhimurium infection of the gut via inflammasome-dependent sloughing of infected epithelial cells. Here we determined that concurrent caspase 1/11-dependent release of the goblet cell-derived mucin, Muc2, into the intestinal lumen also controls Salmonella burdens in infected mice. The increased release of mucins from goblet cells in the cecum and nearby proximal colon, and the subsequent thickening of the protective mucus barrier layer in the distal colon, were all dependent on the cytokines interleukin (IL)-18 and IL-22, as deficiencies in either cytokine resulted in reduced mucin secretion. Supplementation of IL-18 into IL-22 deficient mice restored mucin secretion, indicating that IL-22 acted upstream of IL-18 secretion during infection. In contrast, IL-18 and IL-22 independent signaling through Nlrp6 underlies only a modest, infection-induced increase in mucin secretion from goblet cells in the distal colon. These findings reveal that inflammasome signaling orchestrates multiple levels of protection centered on the intestinal epithelium, including pyroptosis and expulsion of infected enterocytes, as well as the release of mucins by goblet cells in the cecum and along the length of the colon. Our studies underscore the pivotal, multi-faceted role of inflammasome signaling in promoting host defense at the intestinal mucosal surface.