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Recycling aluminosilicate-based solid wastes is imperative to realize the sustainable development of constructions. By using alkali activation technology, aluminosilicate-based solid wastes, such as furnace slag, fly ash, red mud, and most of the bio-ashes, can be turned into alternative binder materials to Portland cement to reduce the carbon footprint of the construction and maintenance activities of concrete structures. In this paper, the chemistry involved in the formation of alkali-activated materials (AAMs) and the influential factors of their properties are briefly reviewed. The commonly used methods, including X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), nuclear magnetic resonance spectroscopy (NMR), and X-ray pair distribution function technology, to characterize the microstructure of AAMs are introduced. Typical characterization results of AAMs are shown and the limitations of each method are discussed. The main challenges, such as shrinkage, creep, efflorescence, carbonation, alkali–silica reaction, and chloride ingress, to conquer for a wider application of AAMs are reviewed. It is shown that several performances of AAMs under certain circumstances seem to be less satisfactory than traditional portland cement systems. Existing strategies to improve these performances are reviewed, and recommendations for future studies are given. [ABSTRACT FROM AUTHOR]

The densification of a SiCp/Al–Fe–V–Si billet was achieved by reducing the pores and oxide film between the particles by rolling. The wedge pressing method was used to improve the formability of the composite after jet deposition. The key parameters, mechanisms, and laws of wedge compaction were studied. The results showed that the pass rate was reduced by 10 to 15 percent when using steel molds during the wedge pressing process if the distance between the two ends of the billet was about 10 mm, which was beneficial to improve the compactness and formability of the billet. The density and stress of the surface of the material were higher than those of the interior, where the distribution of density and stress tended to be uniform as the overall volume of the material shrank. During the wedge extrusion process, the material in the preforming area was thinned along the thickness direction, while the material in the main deformation area was lengthened along the length direction. Under plane strain conditions, the wedge formation of spray-deposited composites follows the plastic deformation mechanism of porous metals. The true relative density of the sheet was higher than the calculated value during the initial stamping phase, but was lower than the calculated value when the true strain exceeded 0.55. This was due to the accumulation and fragmentation of SiC particles, which made the pores difficult to remove. [ABSTRACT FROM AUTHOR]

Earthworms are an important ecological group, especially in agricultural regions in Northeast China. However, fewer studies focus on this group of organisms compared with other faunal groups. Here, we sequenced 15 new mitogenomes of Aporrectodea tuberculata Eisen, 1874, A. trapezoides Duges, 1828, Eisenia nordenskioldi Eisen, 1878 and Drawida ghilarovi Gates, 1969 in Northeast China using a high-throughput sequencing platform. These incomplete linear and double-stranded mitogenomes vary from 14,998 bp to 16,123 bp in size and include 37 genes and a putative control region. Intraspecific genetic divergence was quantified in the lumbricid species, and a control region in D. ghilarovi was reported for the first time by comparison to the mitogenomes of the congeners. Phylogenetic analysis based on coding genes and ribosomal DNA datasets using BI and ML inferences showed the non-monophyly of Aporrectodea and polyphyly of E. nordenskioldi. Future works should examine the taxonomy, phylogeny and population genetics not only of Lumbricidae but also the other earthworm families on the global scale using mitogenomic and nuclear data. [ABSTRACT FROM AUTHOR]

The urban heat island (UHI) effect has a significantly negative impact on the living environment in urban areas. Asphalt pavement is one of the most widely used infrastructures that absorbs solar energy, which leads to the UHI effect and premature failure. As a result, cool pavement technology has been rapidly developed in recent years to mitigate the UHI effect originating from asphalt pavement. Although several outstanding review articles have analyzed previous studies on cool pavement technologies, very few review articles have focused on how to design and expand cool pavement technology from a materials perspective. In this mini-review article, the theoretical and practical factors of the solar reflective coatings and phase-change materials, which are significantly dependent on the design of new materials, have been summarized. The main challenges and potential problem-solving ideas have been presented. In a cool pavement, the solar reflective coatings are composed of epoxy resin or acrylic polymer matrix filled with solar reflective nanoparticles, such as TiO2, SiO2, ZnO, Al2O3, or Fe2O3. The main challenges of the solar reflective coatings are the spalling of the coating polymers from the asphalt pavement surface and the dispersion of the solar reflective nanoparticle in the polymer matrix. Most importantly, it is critical to harmonize the balance between the bonding strength, aging rate, solar reflectance, curing requirements, mechanical properties, and durability of the solar reflective coating. For the nanofillers, the cost of the filler materials, the balance between UV, visible light, and near-infrared reflectance and the dispersion status of the nanofillers in the polymer matrix are the primary factors that must be concerned. For the phase-change materials (PCMs), the interaction between the asphalt and the PCMs, the decomposition of the PCMs, the toxicity of the PCMs, the distribution status of the PCMs in the asphalt matrix, and the cost are the main factors that have to be considered in constructions. This review article can not only provide basic knowledge for the development of new solar reflective pavement materials but also serve as a guide for practical applications of cool pavement in the field. [ABSTRACT FROM AUTHOR]

It is known that random noises have a significant impact on differential systems. Recently, the influences of random noises for impulsive systems have been started. Nevertheless, the existing references on this issue ignore the significant phenomena of nonlinear impulses and time-varying delays. Therefore, we see the necessity to study the influences of random noises for impulsive systems with the above two factors. Stimulated by the above, a polynomial random noise is introduced to suppress the potential explosive behavior of the nonlinear impulsive differential system with time-varying delay. Fortunately, the stochastically controlled impulsive delay differential system admits a unique global solution, is bounded, and grows at most in the polynomial form. [ABSTRACT FROM AUTHOR]

Stochastic robustness of discrete noises has already been proposed and studied in the previous work. Nevertheless, the significant phenomenon of delays is left in the basket both in the deterministic and the stochastic parts of the considered equation by the existing work. Stimulated by the above, this paper is devoted to studying the stochastic robustness issue of delayed discrete noises for delay differential equations, including the issues of robust stability and robust boundedness. [ABSTRACT FROM AUTHOR]

Bauxite residue (red mud) is a solid waste resulting from the aluminum production industry. Disposal or landfill of the red mud (RM) poses irreversible environmental problems; therefore, it is compelling to find practical solutions that can mitigate the negative environmental problems of RM stacking storage. In the past decades, although the recycling of RM has achieved significant progress, challenges remain from both academic and practical perspectives. Previous studies have demonstrated that all the aluminosilicate-based solid wastes have pozzolanic activity, and thus can be considered as resources to manufacture eco-friendly cementitious materials to relieve the carbon emission burden. Therefore, combining RM and other solid wastes to manufacture green cementitious materials has become a promising route to alleviate the burden of environmental pollutions. However, challenges from the fluctuation of the chemical compositions, inert activity, heavy metals stabilization, efflorescence, the side effects of the second pollutions from solid wastes, the hydration process, and mutual interaction mechanisms between the various types of solid wastes are still unclear, especially for multi-components RM-based cementitious materials. This review article summarizes the state of the art of mechanical properties, microstructure characterization methodologies, and hydration process and mechanisms of RM along with other solid wastes. The main challenges and future research trends are discussed. This article attempts to summarize the details of the RM recycling technologies that are beneficial to readers in understanding the background knowledge and research methodologies of eco-friendly cementitious materials. [ABSTRACT FROM AUTHOR]

Motivated by the two strategies of intermittent control and discrete feedback control, this paper aims to introduce a periodically intermittent discrete feedback control in the drift part to stabilize an unstable Markov jumping stochastic differential system. It is illustrated that, by the approach of comparison principle, this can be achieved in the sense of almost sure exponential stability. Further, the stabilization theory is applied to Markov jumping stochastic recurrent neural networks. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is an industrial waste from the production of phosphoric acid and phosphate fertilizer. Disposal and landfill of PG pose significant environmental problems due to its hazardous components. Although many researchers have explored the possibility of PG recycling, challenges still exist before it can be high-effectively reused. In particular, a great deal of recent attention has been attracted to explore using PG as raw material to manufacture sustainable composites. The impurities movement, recycling efficiency, and environmental impacts have to be further investigated. This review article summarized the state of the art of the purification process, application areas, and the environmental impacts of PG waste. The main challenges and potential application approaches were discussed. This article is focused on reviewing the details of the PG reusing which benefits the readers on learning the knowledge from previous efforts. The main challenges of reusing PG were discussed from the chemical, physical, and materials perspectives. [ABSTRACT FROM AUTHOR]

Anti-icing is a critical topic in durability assessment for pavement infrastructures, and it varies according to local policies. To provide sufficient information to winter maintenance agencies, and help compare the merits and shortcomings of each strategy, this review summarizes the widely used anti-icing strategies, including elastic surfaces or high-friction overlays, asphalt binders mixed with anti-icing additives, pavement heating technologies, deicers, and fixed automated spray technology, from academic and practical perspectives, as well as explore the impact of deicers on the durability of concrete materials. Furthermore, the costs of each method were compared to evaluate the feasibility of them. This review not only provides a summary of previous anti-icing strategies, but also sheds light on future research trends that may help address the challenges of current anti-icing strategies, and further enhance anti-icing efficiency and reduce life cycle costs. [ABSTRACT FROM AUTHOR]

Lightweight aggregate concrete manufactured by solid waste or recycled by-products is a burgeoning topic in construction and building materials. It has significant merits in mitigating the negative impact on the environment during the manufacturing of Portland cement and reduces the consumption of natural resources. In this review article, the agricultural and industrial wastes and by-products, which were used as cementitious materials and artificial lightweight aggregate concrete, are summarized. Besides, the mechanical properties, durability, and a few advanced microstructure characterization methods were reviewed as well. This review also provides a look to the future research trends that may help address the challenges or further enhance the environmental benefits of lightweight aggregate concrete manufactured with solid waste and recycled by-products. [ABSTRACT FROM AUTHOR]

Collembola display a variety of feeding habits, and prey on many types of food at different trophic levels in the soil. In most cases, their feeding selections are widely varied. In the interest of the food preferences of E. proxima, we attempted to confirm how the Collembola utilize food when feeding on carrion (unusual sources). Four different soil animals (with different stable isotope values and increasing trophic levels) were used to examine whether collembolans can use dead insects as a food resource in specific manners, depending on food preference. Our results demonstrated that the food preference of a collembolan changed significantly after feeding on insects with different feeding habits for 60 days. We found that stable isotope values (δ13C) of Entomobrya proxima approached those of the food sources. A large proportion of the diet (more than 50%) should directly consist of insect body parts, with the remainder consisting of indirectly used, mixed microorganisms naturally growing on animal food, such as fungi (Rhizopus sp., Alternaria sp., Penicillium sp., and Aspergillus sp.) and bacteria (Bacillus sp1. and Bacillus sp2.). Based on this research, the food preference of collembolans is more focused on carcasses (dead insect bodies) than microorganisms during the animal-food decomposition process. [ABSTRACT FROM AUTHOR]

With good high temperature and corrosive resistance performance, ceramic based composites can be used as promising materials to replace metal thermocouple materials. In this study, Si3N4–MoSi2 composites were prepared via hot pressing technology. X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM) were used to analyze the microstructure of the composites. The mechanical properties and electrical conductivity were tested. The results showed that the composites were composed of β-Si3N4, MoSi2, a small amount of Mo5Si3, and an amorphous glassy phase. The MoSi2 phase was evenly distributed in the matrix. The percolation network was formed with increasing MoSi2 content. The strength of the composites reached its maximum value when the MoSi2 content reached a critical point. The electrical conductivity behaved like a typical percolation phenomenon. The percolation threshold was about 30% to 45%. [ABSTRACT FROM AUTHOR]

Carbon nanofiber (CNF), as one of the most important members of carbon fibers, has been investigated in both fundamental scientific research and practical applications. CNF composites are able to be applied as promising materials in many fields, such as electrical devices, electrode materials for batteries and supercapacitors and as sensors. In these applications, the electrical conductivity is always the first priority need to be considered. In fact, the electrical property of CNF composites largely counts on the dispersion and percolation status of CNFs in matrix materials. In this review, the electrical transport phenomenon of CNF composites is systematically summarized based on percolation theory. The effects of the aspect ratio, percolation backbone structure and fractal characteristics of CNFs and the non-universality of the percolation critical exponents on the electrical properties are systematically reviewed. Apart from the electrical property, the thermal conductivity and mechanical properties of CNF composites are briefly reviewed, as well. In addition, the preparation methods of CNFs, including catalytic chemical vapor deposition growth and electrospinning, and the preparation methods of CNF composites, including the melt mixing and solution process, are briefly introduced. Finally, their applications as sensors and electrode materials are described in this review article.