Low Durability Research Articles

Self-Powered Water Splitting of Ni3FeN@Fe24N10 Bifunctional Catalyst Improved Catalytic Activity and Durability by Forming Fe24N10 on Catalyst Surface via the Kirkendall Effect.

Highly efficient water splitting electrocatalyst for producing hydrogen as a renewable energy source offers potential to achieve net-zero. However, it has significant challenges in using transition metal electrocatalysts as alternatives to noble metals due to their low efficiency and durability, furthermore, the reliance on electricity generation for electrocatalysts from fossil fuels leads to unavoidable carbon emissions. Here, a highly efficient self-powered water splitting system integrated is designed with triboelectric nanogenerator (TENG) and Ni3FeN@Fe24N10 catalyst with improved catalytic activity and durability. First, the durability of the Ni3FeN catalyst is improved by forming N, P carbon shell using melamine, polyetherimide, and phytic acid. The catalyst activity is improved by generating Fe24N10 in the carbon shell through the Kirkendall effect. The synthesized Ni3FeN@Fe24N10 catalyst exhibited excellent bifunctional catalytic activity (ηOER = 261.8 mV and ηHER = 151.8 mV) and remarkable stability (91.7% in OER and 90.5% in HER) in 1 m KOH. Furthermore, to achieve ecofriendly electricity generation, a rotation-mode TENG that sustainably generate high-performance is realized using butylated melamine formaldehyde. As a result, H2 is successfully generated using the integrated system composed of the designed TENG and catalyst. The finding provides a promising approach for energy generation to achieve net-zero.

Regenerative Superhydrophobic Coatings for Enhanced Performance and Durability of High-Voltage Electrical Insulators in Cold Climates.

Superhydrophobic coatings can be a suitable solution for protecting vulnerable electrical infrastructures in regions with severe meteorological conditions. Regenerative superhydrophobicity, the ability to regain superhydrophobicity after being compromised or degraded, could address the issue of the low durability of these coatings. In this study, we fabricated a superhydrophobic coating comprising hydrophobic aerogel microparticles and polydimethylsiloxane (PDMS)-modified silica nanoparticles within a PDMS matrix containing trifluoropropyl POSS (F-POSS) and XIAMETER PMX-series silicone oil as superhydrophobicity-regenerating agents. The fabricated coating exhibited a static contact angle of 169.5° and a contact angle hysteresis of 6°. This coating was capable of regaining its superhydrophobicity after various pH immersion and plasma deterioration tests. The developed coating demonstrated ice adhesion as low as 71.2 kPa, which remained relatively unchanged even after several icing/de-icing cycles. Furthermore, the coating exhibited a higher flashover voltage than the reference samples and maintained a minimal drop in flashover voltage after consecutive testing cycles. Given this performance, this developed coating can be an ideal choice for enhancing the lifespan of electrical insulators.

Effect of Na/Al and curing moisture conditions on sodium aluminosilicate hydrate (N–A–S–H) geopolymers’ hydric properties

Anthropogenic climate change is one of the main reasons for mainstreaming sustainability in all sectors. Reducing the carbon footprint of the built environment is one of the sustainability goals which is universally accepted. Reducing the carbon emissions from buildings entails cutting back operational and embodied carbon. Geopolymers are one of these materials that have been under focus recently for their capacity to reduce these two sources’ emissions in buildings. In this study, the authors added to their previous work on understanding aerated geopolymers’ performance as building materials. This article presents the effect of Na/Al ratio and curing moisture on the moisture storage, transfer, and moisture buffering capacity (MBC) of aerated geopolymers. The impact of vapor gradient and exposure to variable environmental conditions (temperature and relative humidity(%RH)) are also surveyed. Generally, the results show correlations between hydric performance and the tested experimental parameters. This stems from the influence of Na/Al and curing relative humidity on the degree of geopolymerization, rate of reaction, porosity, and phase composition of metakaolin-based geopolymers. Vapor permeability and moisture diffusivity increased with rising alkali oxide content because of the higher degree decomposition of porogen and pore stabilization effect of rapid polycondensation. Moisture permeability and diffusivity also showed direct relationships with curing relative humidity. Low relative humidity results in the rapid loss of inter-layer water and leads to densification of the matrix, while high %RH curing is suitable for pore formation and stability. The MBC of the samples increases with increasing Na/Al because of increased porosity leading to access to more gel pores. However, at high values, the sub-carbonation (internal carbonation) and carbonation lead to the formation of sodium carbonate, which is highly hydrophilic and influences the material's moisture exchange capacity negatively. This justifies the lower MBC at Na/Al=1. A similar observation was made when curing moisture content was increased. The influence of the Na/Al and curing moisture on the pore statistics of the geopolymer matrix are observed by their adsorption isotherms. At lower curing humidity and Na/Al, the samples tend to be less macroporous, dominated mainly by micropores. This is evidenced by the onset of capillary condensation at low %RH because of raid pore filling. The results also demonstrate the critical role Na/Al plays in determining the resulting matrix’s microstructural integrity. This is evidenced by the low durability of the sample with Na/Al equal to 1.2. The samples’ loss of structural integrity is because of carbonation-triggered retardation of strength development and stress put on micropores because of sub-carbonation-driven crystallization.

Improvements in Hydrolytic Stability of Alkali-Activated Mine Tailings via Addition of Sodium Silicate Activator.

Over 14 billion tons of mine tailings are produced throughout the world each year, and this type of waste is generally stored onsite indefinitely. Alkali activation is a promising strategy for the reuse of mine tailings to produce construction materials, converting this waste stream into a value-added product. One major problem with alkali-activated mine tailings is their low durability in water (i.e., low hydrolytic stability). In this article, the influence of a mixed sodium hydroxide/sodium silicate alkali activator on the compressive strength, hydrolytic stability, and microstructure of alkali-activated materials (AAMs) were systematically investigated. XRD, FTIR, NMR, and NAD were used to investigate microstructural changes, and a water immersion test was used to show improvements in hydrolytic stability. For gold mine tailings activated with pure sodium hydroxide, the compressive strength was 15 MPa and a seven-day water immersion test caused a strength loss of 70%. With an addition of 1 M sodium silicate in the activator, the AAMs achieved a compressive strength of over 30 MPa and strength loss of only 45%. This paper proposes a mechanism explaining why the strength and hydrolytic stability of AAMs are dependent on the dosage of soluble silicate. A high dosage of sodium silicate inhibits the depolymerization of the source material, which results in a sample with less amorphous aluminosilicate gel and, therefore, lower hydrolytic stability.

Understanding the effect of bondcoat surface treatment on enhanced lifetime of suspension plasma sprayed thermal barrier coatings

Thermal barrier coatings (TBCs) are extensively used in gas turbine engines in power generation and aerospace applications. Improvements in TBC performance and lifetime are continuously pursued by the gas turbine industry. Suspension plasma spraying (SPS) has shown promising results in recent years as it could produce a porous columnar TBC microstructure exhibiting low thermal conductivity and high durability. Further improvements in lifetime and fundamental understanding of failure mechanisms would lead to their wider application.Lifetime of a TBC system is dependent not only on the topcoat microstructure and chemistry, but also on topcoat-bondcoat interface and bondcoat characteristics as they influence the growth rate of thermally grown oxide (TGO) layer as well as the mismatch stresses generated in the topcoat during operation. Moreover, in SPS TBCs, the column density and porosity in the topcoat are also affected by the bondcoat surface roughness which in turn affects TBC lifetime. In previous work, it was shown that bondcoat surface treatment by shot peening followed by light grit blasting can significantly enhance the cyclic lifetime of SPS TBCs.The objective of this work was to gain further insight into the lifetime improvements due to surface treatment of bondcoat. Commercial NiCoCrAlY powder was deposited by high velocity air fuel (HVAF) and high velocity oxy fuel (HVOF) spraying while SPS was used to deposit yttria stabilised zirconia topcoat. Before spraying the topcoat, the bondcoat samples were subjected to vacuum heat treatment, shot peening, and/or grit blasting. Residual stress measurements were performed by X-ray diffraction on samples with different variants of bondcoat treatments and compared with Almen strip tests. The lifetime was examined by thermal cyclic fatigue testing. The relationships between changes in bondcoat surface roughness, residual stress state and microstructure due to surface treatments, and resultant topcoat microstructure and lifetime were studied and discussed.

Reliability evaluation for shot-peening conditions affecting durability life of automotive suspension coil springs

Shot peening (SP) is a cold working method used to improve the fatigue life and corrosion resistance of metallic materials subjected to repeated loading. However, optimal SP conditions can only be found through experiments with actual operating parts. In addition, studies on the effective SP conditions and ensuring safety for improving the durability of parts are lacking. In this study, SP of various conditions were applied to automobile suspension coil springs (ASCS). Consequently, the process factors, damage assessment, and microstructure were analyzed to determine the factors that exerted a dominant effect on durability life. The durability life of springs applied with stress SP (SSP) was evaluated to be approximately 3.8–4.8 times higher compared to that of springs applied with other SP conditions. In addition, by analyzing the process factors affecting the durability life, the absence of a direct effect of the arc height and Vickers hardness was observed. Moreover, the effect of surface roughness was observed to be small. However, the durability life in response to the change in maximum compressive residual stress (MCRS) exhibited a tendency to change linearly, and this relationship was expressed in an equation through regression analysis. The fracture surface of spring with a high durability life tended to have a large number of spiral shapes, and that of spring with a low durability life tended to have a large number of flat shapes. Before conducting the durability test, a circumferential metal flow was observed in the work-hardened layer below the spring surface upon shot peening. After conducting the durability test, partial crack initiation and propagation and delamination were observed in these areas. Despite the varying SP conditions, the surface microstructure of each spring was observed to be similar before and after the durability test. In this study, it was confirmed that SSP is the most effective method to improve the durability life of ASCS, and it was possible to understand through damage evaluation and microstructure analysis that MCRS affects the durability life by delaying the initiation of cracks in the spring. The analysis method and results of this study are expected to be useful for improving the reliability of not only ASCS but also SP-applied components in the future.

Robust Low-Friction and Low-Wear TiNbMoTaCr High-Entropy Film Enabled by Periodically Inserting Curved MoS2 Sheets.

The well-known integration of physical, chemical, and mechanical properties enables high-entropy alloys (HEAs) to be applied in various fields; however, refractory HEAs are brittle and susceptible to abrasive wear at high coefficients of friction (COF), resulting in insufficient mechanical durability against abrasion. Herein, curved MoS2 nanosheets are periodically introduced into the TiNbMoTaCr film for triggering the self-assembly mixed metal oxides @MoS2 nanoscrolls, which contain hard mixed metal oxides cores and the low-shearing lubricant MoS2 shells, during the friction in the air environment; such mixed metal oxides@MoS2 nanoscrolls in the friction interfaces can contribute to the robust low friction and low wear. Compared to the pure TiNbMoTaCr film (with high COF of ∼0.78, low abrasive durability identified by worn-out event), the periodic incorporation of 10 nm thickness curved MoS2 sheets can successfully achieve a low COF of ∼0.08 and low wear rate of ∼9.561 × 10-8 mm3/ Nm, much lower than the pure MoS2 film (COF = ∼ 0.21, wear rate = ∼ 1.03 × 10-6 mm3/ Nm). Such superior tribological properties originate from the cooperative interaction of TiNbMoTaCr nanolayers and curved MoS2 nanosheets, accompanied by the self-assembly of mixed metal oxides@MoS2 nanoscrolls. In these nanoscrolls, TiNbMoTaCr can act as an 'air-absorbing agent' to form high-loading mixed metal oxide cores and serve as an 'oxygen sacrificer,' preventing the low-shearing lubricant curved MoS2 nanosheets from oxidation. In addition, even with the soft MoS2, the hardness of the TiNbMoTaCr/MoS2 nanomultilayers can still be well maintained and increased above the calculated values by mixing law, further favoring superior mechanical durability. The synergetic effect of TiNbMoTaCr and curved MoS2 nanosheets during the friction in air can provide a route to design HEA films with enhanced tribological properties for better mechanical durability and broader application prospects.

Preparation of transparent electrospun nanofibrous membrane from long‐persistent phosphor‐reinforced polymer for security authentication

AbstractPhotochromic inks have been a tempting authentication method to make commercial items more resistant to counterfeiting. However, recent studies have shown that photochromic inks have major drawbacks, such as expensiveness and low durability. Herein, we report the development of new photochromic nanofibers for cutting‐edge anti‐counterfeiting uses. Lanthanide‐doped strontium aluminate nanoparticles (LSAN) were synthesized and immobilized onto electrospun polyurethane nanofibers (PUNF). Anti‐counterfeiting materials encapsulated with inorganic photochromic agent can guarantee photostability and durability. LSAN function as an efficient inorganic photochromic agent whereas PUNF function as a hosting matrix. Both of photostability and reversibility of the prepared UV‐induced photochromic LSAN@PUNF were found to be rather high. Applying varying ratios of LSAN resulted in the development of polyurethane nanofibers with distinct emission properties depending on the LSAN content. The nanofibrous films showed green emission under UV illumination, and whereas no traces were detected in visible daylight. LSAN displayed diameters of 3–6 nm, whereas LSAN@PUNF nanofibers had diameters of 150–450 nm. Transparency was indicated by an excitation peak at 347 nm, and a green color was indicated by an emission peak of 530 nm. The current approach can be presented as an efficient technology to prevent forgery of commercial products.

Experimental study on flexural behavior of steel-laminated concrete (NC and UHPC) composite beams with corrugated steel webs

The challenges of the substantial self-weight in prefabricated bridge deck slabs, the presence of numerous scattered steel beam components, and the low durability of bridge deck slabs have long been difficult issues to address in the context of traditional prefabricated steel-normal concrete (NC) composite girder bridges with flat steel webs. This paper proposes a solution through the optimization of structural forms and material properties by introducing a novel structural configuration as prefabricated steel-laminated concrete (LC) composite girder bridges with corrugated steel webs. The flat steel webs were substituted with corrugated steel webs, and the LC bridge deck slab was composed of a NC layer and an ultra-high performance concrete (UHPC) layer. This paper conducted three groups of experimental tests to comparatively analyze the effects of web forms and bridge deck materials on the flexural performance of composite beams. The results indicate that, under the conditions of consistent beam height and steel usage, composite beams with corrugated steel webs have fewer steel components, better stability, and smaller difference in bearing capacity compared to composite beams with flat steel webs. Compared with NC bridge deck slab, laminated bridge deck slab can increase the stiffness and bearing capacity of composite beam by about 13%, and the thickness of the bridge deck slab can be reduced by 20%. Furthermore, this paper presents a shear connection degree calculation method suitable for composite beams with corrugated steel webs, which effectively reduces the number of connectors.

Strategic Analysis of Past and Modern Hydrogen Storage Methods and Prospects for Its Future

This research report provides a comprehensive strategic analysis of past and modern hydrogen storage methods and prospects for its future. A literature review was conducted to identify the most promising materials and technologies for hydrogen storage and to compare their properties to current storage methods. The findings suggest that solid-state storage materials, such as metal-organic frameworks (MOFs) and porous carbon materials, show great promise due to their high storage capacities and favorable thermodynamic properties. However, technical challenges such as slow kinetics and low durability need to be addressed to achieve practical application. Furthermore, the integration of hydrogen storage into existing energy infrastructure presents technical and regulatory barriers that need to be overcome, such as pipeline compatibility and safety regulations. Overall, this research sheds light on the prospects and challenges of hydrogen storage and provides insights for future research and development in this field.

Trend-Chasing Versus Minimalism: Selling Fewer, Better Products to Fashion-Sensitive Customers

Fashion sellers are sometimes critiqued for selling low durability products, resulting in waste. Blame is also directed at consumers, who purchase new fashions despite having accumulated a closet full of prior fashions. The “slow fashion” movement encourages sellers to produce higher durable products, thus supporting less frequent purchases by consumers. Using an infinite-time model and considering strategic consumer behavior, including their ability to accumulate a “closet” of varieties over time, we analyze the seller’s profit-maximizing price and product-durability decisions. We initially assume a static price but later analyze the potential profit gains from dynamic pricing. When analyzing a heterogeneous consumer market, we initially allow customers to vary (distributed uniformly) in their sensitivity to fashion. Subsequently, we explore alternative distributions for consumers’ fashion sensitivity and the correlation between their fashion sensitivities and product valuations. Using this framework, we show how the seller’s optimal price and durability decisions yield distinct shopping segments, which we refer to as the minimalist versus trend-chasers. We find that if the degree of fashion uncertainty is moderate, the seller’s optimal choice of product durability will support the emergence of both behaviors. As the variety uncertainty expands, if the seller’s costs are sufficiently low, it will support a throwaway culture via disposable products. Otherwise, given high costs, the seller optimally targets a slow fashion-type outcome, with consumers targeting reuse (with durability) rather than variety. Our findings shed light on consumers’ optimal purchasing behaviors in relation to both market parameters and the firm’s pricing and durability decisions.

UV-activated semiconductor gas sensor response measurement for formaldehyde detection

The gas sensing characteristics of ultraviolet light-emitting diodes (UV-LEDs)-activated semiconductor sensors were investigated to detect formaldehyde (HCHO) as a model volatile organic compound (VOC). As the major drawback of formaldehyde gas sensors is the low durability of the sensing material, efforts were made to establish a suitable metal oxide semiconductor and to enhance its stability throughout the sensing process. In2O3 nanoparticles (NPs) as the sensing material showed restructuring caused by exposure to different concentrations of formaldehyde in the presence of UV radiation when its morphology and structure were analyzed. UV radiation in the presence of formaldehyde was found to play a critical role in nanoparticles agglomeration, as well as its response inconsistency and instability.The novel method of measuring UV radiation elimination in the initial stages of the response curve was deemed effective for sensing layer preservation in this study. The scanning electron microscopy (SEM) results showed that this approach prevented any notable deformation in the nanoparticles’ shape and size and resulted in reproducible responses to various formaldehyde concentrations (10–50 ppm) in the steady-state and transient (5 min exposure) phases of the response curve. Hence, a short-time UV exposure has the potential to be applied in practical gas sensing applications in which the sensor can be automatically turned off a few minutes after any target gas detection. The gas sensor response slope in the transient phase of the response curve was found to be a very good indicator of target gas concentration and to obtain fast and consistent results while preserving the sensing material from restructuring. The findings of this study can be incorporated into the development of UV-LED-activated gas sensors where stable and fast response measurements of VOCs are required.

High voltage, toughness and improved interfacial ion deposition through a dual-crosslinked and self-healable hydrogel electrolyte for green zinc-ion batteries

The inconsistent zinc stripping/deposition leading to low durability of zinc anodes is a fundamental obstacle for the practical application of zinc-based aqueous batteries. Hence, the self-healing capability of flexible batteries is crucial for enhancing their durability and dependability during routine operation, as it allows them to withstand various deformations. Through composite strengthening and dynamic coordination complexation, we have developed a dual-crosslinked and natural polymer-based self-healing hydrogel electrolyte (sodium carboxymethyl cellulose/sodium alginate-Zn2+, denoted as CMC/SA-Zn2+) for flexible Zn-MnO2 batteries. The metal coordination interactions of carboxyl groups with Zn2+ as the dynamic motif are contributed to excellent mechanical and electrochemical properties, as well as fast self-healing ability for the CMC/SA-Zn2+ hydrogel electrolyte. Moreover, the improved compatibility of the electrode and electrolyte at their interfaces results in considerably more meticulous Zn deposition. Subsequently, a reversible plating/stripping performance is observed in a symmetric cell for a duration of 2000 h. After applying this self-healing and tough electrolyte to the flexible Zn-MnO2 battery, it is constructed with a high capacity of 218 mAh/g and a high coulombic efficiency close to 100 %. Additionally, the flexible batteries exhibit exceptional resilience and can recover their electrochemical performance even after enduring multiple mechanical damages, highlighting their potential use in wearable electronics.

Effect of Thermal Modification on the Density, Durability, Dimensional Stability, and Mechanical Properties of Pinus caribaea

Pinus caribaea (Pine) is an underutilized timber species in Sri Lanka due to its low density, durability, dimensional stability, and undesirable colour. This research aims to examine the enhancements in the physical and mechanical properties of Pinewood through thermal modification (TM) and compare the properties of the TM wood with kiln-dried and untreated wood and with the properties of high-graded timbers of Tectona grandis (teak) and Koompassia malaccensi (kempas). TM is a process that involves heating wood to high temperatures (2000 C) in the absence of oxygen, which removes the moisture and creates changes in the wood at the cellular level. The effectiveness of the thermal modification on density, modulus of rupture (MOR), modulus of elasticity (MOE), moisture content, dimensional stability, durability, and colour was studied. Specific gravity of thermally modified wood was 6% higher than untreated wood, but lower than teak and kempas. MOR and MOE values were 35.75% and 46.46% respectively higher than untreated wood. Equilibrium moisture content was reduced after TM and volumetric shrinkage of TM was reduced to 2.16% and swelling under liquid water contact was reduced to 2.37%. Thermally modified timber was classified as not durable (DC 5) based on field test (EN 252, 2014) results. However, TM timber was slightly durable (DC 4) according to laboratory tests and showed better fungal resistance. The wood underwent a darkening effect as a result of thermal modification, resembling the colour of teak. The cost of TM was 13.1% higher than kiln drying. Improved dimensional stability, enhanced bending strength, and attractive appearance demonstrate the potential of thermal modification as a promising alternative for transforming P. caribaea wood into high-value raw material. TM timber finds suitable applications in indoor furniture and joinery projects. However, due to its lack of termite resistance, preservative treatment is recommended for outdoor ground contact usage.
 
 Keywords: Thermally modified timber, Mechanical properties, Dimensional stability, Durability,
 Pinus caribaea

Development of Self-Sensing Asphalt Pavements: Review and Perspectives

The digitalization of the road transport sector necessitates the exploration of new sensing technologies that are cost-effective, high-performing, and durable. Traditional sensing systems suffer from limitations, including incompatibility with asphalt mixtures and low durability. To address these challenges, the development of self-sensing asphalt pavements has emerged as a promising solution. These pavements are composed of stimuli-responsive materials capable of exhibiting changes in their electrical properties in response to external stimuli such as strain, damage, temperature, and humidity. Self-sensing asphalt pavements have numerous applications, including in relation to structural health monitoring (SHM), traffic monitoring, Digital Twins (DT), and Vehicle-to-Infrastructure Communication (V2I) tools. This paper serves as a foundation for the advancement of self-sensing asphalt pavements by providing a comprehensive review of the underlying principles, the composition of asphalt-based self-sensing materials, laboratory assessment techniques, and the full-scale implementation of this innovative technology.

Chemical Composition and FTIR Analysis of Acetylated Turkey Oak and Pannonia Poplar Wood

In this research, acetylation was applied under industrial conditions to improve the properties of Turkey oak and Pannonia poplar wood. Both species are potential “climate winners” in Hungary, yet they are currently underused due their low durability and poor dimensional stability. The acetylation modification process may be a suitable method to improve their properties. In order to verify the effectiveness of the process, comparative chemical analyses (cellulose, hemicelluloses, lignin, extractives, ash, buffering capacity, and pH) of the untreated and acetylated heartwood and sapwood were carried out for both species for the first time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was also used to support the evaluation of the chemical analyses. The weight percent gain was 11.54% for poplar and 0.94% for Turkey oak, indicating poor treatment efficiency for the latter. The cellulose, hemicelluloses, and lignin contents changed significantly in poplar, with the highest change (+81%) induced by acetylating the hemicelluloses. Only the alpha-cellulose content decreased significantly in Turkey oak, presumably due to the degradation of the non-crystalline part of the cellulose. Acetylation may improve the resistance of Pannonia poplar against moisture, weather, decay, and wood-boring insects, but the process parameters need to be optimized in order to prevent degradation and discoloration in poplar. Turkey oak was found to be less suitable for acetylation due to its low permeability and tendency to crack.

Horizontal fire spread by foam-backed, polypropylene carpet

An eight year old boy was badly injured by a fire in his bedroom in May 2005. He spent his ninth birthday in intensive care and died a month later. This case study discusses a missing link into the pattern of fire development which made it difficult to identify the point of ignition. An absence of burning to the floor and isolated areas of burning seemed incongruous with the general pattern of fire development. Several fire investigation texts suggest that carpet cannot spread fire by itself; those texts that do mention the possibility, do not describe the mechanism in detail, nor what evidence an investigator might expect to see after the fire.Experimentation with samples of carpet gave good insight into the mechanism and its effects, thereby providing the missing link by which to connect the areas of burning and identify the point of origin. If elements of the mechanism described in this paper are known, a reader could discern enough from the many papers available to support a working hypothesis but as yet, there is no single paper that describes the phenomenon mechanistically from start to finish, especially to those who have not encountered elements of it before; hence, this paper presents some novel findings.The test involved polypropylene fibre carpets with integral polyurethane foam underlay, a very common type of carpet owing to its low cost and high durability. This is, therefore, an important mechanism of fire spread for fire investigators to be aware of and to understand. As this is a case study, rather than a research paper, the matters are dealt with empirically so the author cautions that when considering this mechanism in a new matter, the investigator should make their own tests of its validity.

Multiscale hybrid-structured femtosecond laser-induced graphene with outstanding photo-electro-thermal effects for all-day anti-icing/deicing

Multifunctional materials with photothermal and electrothermal effects have garnered considerable attention for solving the icing problem. Although great progress has been made in the field of anti-icing/deicing, the low electrothermal performance, complicated fabrication methods, and low durability restrict their widespread application. Here, we fabricate multiscale hybrid-structured femtosecond laser-induced graphene (FsLIG) on polyimide (PI) substrates using femtosecond laser direct writing technology in ambient air, and apply the FsLIG to all-day anti-icing/deicing. With the optimized laser scanning speed, the as-fabricated surface exhibits high light absorption rate (∼98.5%) in the range of 220–1400 nm and low sheet resistance (∼18.2 Ω sq−1), which bestows outstanding photo-electro-thermal effects on the FsLIG surface. Under 1.0 sun illumination or an applied voltage of 4 V, the average surface temperature can rise to ∼69.3 °C or ∼193.1 °C within 30 s. As a result, the FsLIG is successfully applied in anti-icing/deicing. The FsLIG surface realizes anti-icing and deicing when exposed to a sunlight intensity or an applied voltage of 1.0 sun or 2 V. The photo-electro-thermal material developed in this work, along with its simple preparation method, might have broad application prospects in the field of anti-icing/deicing.

Low-carbon efficiency assessment for Hong Kong's oceanic artificial cities applying the novel prefabricated diaphragm wall technology

Oceanic artificial cities built by reclamation are vital for addressing the future sustainable development of land in Hong Kong. However, traditional cast-in-situ (CIS) construction methods face issues such as significant environmental impacts and low durability, making it challenging to meet the requirements of low-carbon and resilient development. To address these challenges, a novel low-carbon construction technology for oceanic artificial cities is proposed: prefabricated two-wall-in-one diaphragm wall (PTDW). This study aims to address the comprehensive assessment and decision-making issues of greenhouse gas (GHG) emissions and load-bearing performance. First, the adaptability of PTDW technology to oceanic artificial cities is introduced. Second, the Carbon-mechanics Dual-control Assessment Model-Section level (CDAM-SL) is established. Finally, CDAM-SL is used to assess the GHG reduction efficiency of construction technologies for oceanic artificial cities. The results reveal the following key findings: (1) The Bearing Property Indicators (BPI) of the PTDW-Cavity scheme surpass the CIS scheme across the construction and operation phases. (2) Comparing to the traditional CIS scheme, the GHG emissions of the PTDW-Cavity scheme are reduced by 33.31% (8.65 t CO2e). This reduction is primarily attributed to PTDW technology, which eliminates the temporary enclosure structure construction. Furthermore, the refined PTDW technology significantly decreases the GHG emissions of precast components and enhances drainage performance. (3) The GHG reduction efficiency of the PTDW-Cavity scheme consistently outperforms the CIS scheme across both phases. Consequently, PTDW technology demonstrates significant advantages in load-bearing performance and GHG emissions reduction. The research findings provide a theoretical foundation and applicable tool for the comprehensive assessment and decision-making of low-carbon construction technology for oceanic artificial cities.

Application of superabsorbent natural polymers in agriculture

To meet global food demand, reduce waste, and minimise environmental impact, the agricultural sector must improve its current practices on soil amendment, fertiliser encapsulation, and seed and crop protection. Super absorbent polymers (SAPs) are a class of polymeric materials that can absorb and retain large quantities of liquids/aqueous solutions compared to their own mass. Typically, SAPs are cross-linked to form three-dimensional hydrophilic networks, commonly known as hydrogels. Although SAPs can be synthesised from both synthetic and naturally sourced materials, for agricultural applications they are generally composed of synthetic polymers, due to their advantageous properties. These include higher water absorption rate and capacity, low cost, availability, durability, and mechanical performance. However, many of these systems utilise polyacrylic acid (PAA) and polyacrylamide (PAM) monomers which may have toxic effects on the nervous and respiratory systems of humans and animals. To ensure sustainable agricultural practices and maintain healthy long-term crop output, synthetic SAP usage must be greatly reduced. This review article aims to investigate alternative natural SAPs for agriculture and critically rationalise their adoption into the industry. Specific applications investigated include (i) soil amendment, (ii) fertiliser encapsulation, (iii) seed coating, and (iv) crop protection.