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Understanding the effects of pressure and oxygen concentration on the flame spread behaviors of electrical wires is crucial for establishing fire safety strategies for plateau cities, aircraft, and spacecraft. During the combustion, the polymeric coating first liquefies to form molten agglomerations, after which these droplets boil to release combustible gases that propagate the combustion process, which brings a potential fire threat. To better evaluate this fire risk, the flame spread of polyethylene (PE) and ethylene tetrafluoroethylene (ETFE)-insulated nichrome wires was investigated in a subatmospheric cabin. During the combustion of the insulation, the PE flame always presents a closed teardrop-like structure, while at the limiting oxygen concentration condition, the ETFE flame presents an asymmetric pentagram-like structure due to uneven heat losses. In this experiment, dripping was exhibited only by the PE insulation mainly because of the difference in surface tension. When the oxygen concentration was raised from 21% to 30%, the critical pressure for dripping shifts from 60 kPa to 38 kPa. Air pressure has a slight negative effect on flame spread rates, because, at lower pressure, the burning rate is lower, but the heat loss and convective and radiant heats of the flame decrease. [ABSTRACT FROM AUTHOR]

A series of all‐inorganic lead‐free halide perovskite inverse opals were prepared and furtherly used as the photocatalysts to promote the polymerization of 3, 4‐ethylenedioxythiophene (EDOT) under the irradiation of visible light. All the samples exhibited the nice replica of the artificial template and high crystallinity. The bandgap of the catalysts was adjusted by screening the ratios of bromide to iodide and antinomy to bismuth, respectively. Among all the samples, Cs3Bi0.5Sb1.5Br9 inverse opal showed the best catalytic performance and the excellent stability in terms of the morphology and the crystalline phase after four cycles of photocatalytic polymerization. Since EDOT is commercially available, the present observation suggested a convenient protocol of preparing the composited materials or optoelectronic devices based on the lead‐free halide perovskites and the conductive poly(3, 4‐ethylenedioxythiophene). [ABSTRACT FROM AUTHOR]

Layered transition metal dichalcogenide rhenium selenide (ReSe2) has attracted great attention as an electrocatalyst for the hydrogen evolution reaction (HER) due to its excellent stability and sufficient active sites. However, ReSe2 has intrinsically poor conductivity, which leads to the insufficient utilization of electrocatalytic active sites. Herein, we designed the regulation of the electronic band structure by W replacement in ReSe2 nanosheets to greatly improve the conductivity. The Re0.7W0.3Se2 exhibits an overpotential of 141 mV at 10 mA cm−2 and a Tafel slope of 65.3 mV dec−1, superior to that of the original ReSe2 and WSe2. This work aims to provide a feasible strategy to promote the HER activity of ReSe2. [ABSTRACT FROM AUTHOR]

Herein, a novel Z‐scheme heterojunction of nickel disulfide (NiS2)/graphitic carbon nitride (g‐C3N4)/(tin disulphide) SnS2 has been successfully prepared by a simple one‐step hydrothermal method. Compared to the pristine g‐C3N4, a considerable enhancement on the photocatalytic activity of the heterojunction for the photodegradation of methyl orange was obtained, which is attributed to the promoted separation and transfer of the photo‐induced exciton due to the formation of Z‐scheme mechanism in NiS2/g‐C3N4/SnS2 composites. In particular, the composite of 1 %‐NiS2/g‐C3N4/SnS2 shows the highest apparent quasi‐first‐order rate constant of 0.0633 min−1 for the photodegradation of methyl orange, which is 6.96 times and 2.50 times as large as that of the pristine g‐C3N4 and 5 %‐SnS2/g‐C3N4, respectively. [ABSTRACT FROM AUTHOR]

Fire safety is a significant concern in aviation as well as space travel and settlement, where reduced pressure and raised oxygen concentration are used. Electrical wire has been identified as a major fire hazard in these special applications. Besides the flame spread in wire insulation, the molten insulation surrounded by a flame can drop due to gravity. Such flame dripping in wire fire represents an important and different type of fire risk but has been ignored. To better evaluate the aircraft fire risk, we conduct laboratory experiments with thin nichrome and copper wire samples under various ambient oxygen concentration and pressure. For the first time, we find two important limits for wire fire, the upper dripping limit and the lower extinction limit, as a function of pressure and oxygen concentration. Between these two limits, both the spread of flame and dripping accompanied by flame occur, defining the worst fire-wire scenario. In the "normoxic" atmosphere (i.e., oxygen partial pressure of 21 kPa), dripping occurs to the copper wire below 70 kPa, but never to the low-conductivity nichrome wire. The mass of drip is controlled by the force balance between gravity, surface tension, and inertia forces, and it is insensitive to the wire size and core material while changes with the ambient condition. At the extinction limit, the wire core changes from a heat source to a heat sink as the oxygen concentration is decreased. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) incineration contributes significantly to carbon emissions, and has become a serious problem in China, which has seen an exponential rise in waste over the last twenty years due to rapid urbanization and the associated consumer economy growth. To tackle this issue, this paper develops a leader-follower optimized approach for economic and environmental equilibrium in incineration power plants that includes a carbon allowance allocation scheme (IPP-CAAS) under combustion and pollutant limitations. In the leader-follower (bi-level) game, the regional authority on the upper level determines the carbon allocations and environmental targets and the IPPs on the lower level develop schemes to maximize revenue under the upper-level restrictions. By employing uncertain parameters for the carbon and power conversion fluctuations, the approach is able to more accurately depict the industry characteristics of waste incineration process in this carbon-economy balance problem. The robustness and practicality of the proposed methodology was then validated through a case study. Scenario analysis under different political parameters indicates that the proposed methodology can assist the authorities to achieve carbon-economy trade-off and under serious carbon-control situations, encourage the IPPs to reduce their blended coal ratios, and invest in low-carbon incineration technology. Managerial insights on further industrial developments are also given for the authority and relevant practitioners. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive overview on the biomedical applications of electrical stimulation (EStim). EStim has a wide range of direct effects on both biomolecules and cells. These effects have been exploited to facilitate proliferation and functional development of engineered tissue constructs for regenerative medicine applications. They have also been tested or used in clinics for pain mitigation, muscle rehabilitation, the treatment of motor/consciousness disorders, wound healing, and drug delivery. However, the research on fundamental mechanism of cellular response to EStim has fell behind its applications, which has hindered the full exploitation of the clinical potential of EStim. Moreover, despite the positive outcome from the in vitro and animal studies testing the efficacy of EStim, existing clinical trials failed to establish strong, conclusive supports for the therapeutic efficacy of EStim for most of the clinical applications mentioned above. Two potential directions of future research to improve the clinical utility of EStim are presented, including the optimization and standardization of the stimulation protocol and the development of more tissue-matching devices. [ABSTRACT FROM AUTHOR]

Heterostructure transition metal derivatives have been extensively studied in electrocatalysis, but most of the hybrid samples are on nanoscale with low stability and tap density. ZnO microspheres are applied as a sacrificial template, followed by alkaline etching and aluminum reduction to construct Ni/Co3O4 microcubes. The porous hybrid microcubes show stirring performance in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For HER, it exhibits comparable overpotential of 145 mV at 10 mA cm−2 as Pt/C (101 mV) and desirable stability. For OER, it outperforms RuO2 with lower overpotential when the current exceeds 17.8 mA cm−2 and much smaller Tafel slope of 34 mV dec−1 versus RuO2 (72 mV dec−1). The potential activity is assigned to the charge transfer at the heterointerfaces, and the synergic effects of the Ni/Co3O4 phases, which possibly will cast light on the design of microscale bifunctional electrocatalysts. [ABSTRACT FROM AUTHOR]