•Sides-sealed PMMA was compared with 3D flame spread development.•Thickness and width effects on upward flame spread were explored.•A new methodology about mass loss rate prediction was ...developed.•Dimensionless flame height was scaled with dimensionless heat release rate for wall flame.
Upward flame spread has the same propagating direction with air flow and buoyancy, and features as the most hazardous fire case in all flame spread configurations. It has been a long time for fire researchers to find a simple and effective method to evaluate upward flame spread behaviors, especially for different materials and sample sizes. The aim of this work was motivated by the research of sample width and thickness effects on upward flame spread behavior, including flame spread rate during acceleration propagation for different sample thickness and width, theoretical global mass loss prediction based on Emmons’s hypothesis, and dimensionless flame height scaling with dimensionless heat release rate for steady stage burning. Four kinds of sample thicknesses were selected, including 1.7, 3.5, 5, and 7mm. For each kind of thickness, six sample widths ranging from 40 to 90mm were prepared. To eliminate the side flame spreading effects, one set of contrast experiments with sample sides sealed was also performed, by which way flame could only spread along sample front surface and flame propagation was inhibited along both sides. Based on Emmons’s hypothesis, a method for calculation of global mass loss rate was developed. Theoretical global mass loss rate over pyrolysis surface of upward flame spread configurations was calculated and could fit the experimental data well. Finally, a dimensionless heat-release rate for wall flames of different sample sizes was used to scale the dimensionless flame height with a power-law exponent 0.58. The results of this study have implications concerning designs for high-rise building fire safety problems and can help to get better understandings of upward flame spread mechanism from aspects of heat and mass transfer.
Sepsis is a systemic inflammatory response syndrome caused by infection, resulting in organ dysfunction. Sepsis‐induced acute kidney injury (AKI) is one of the most common potential complications. ...Increasing reports have shown that M1 and M2 macrophages both take part in the progress of AKI by influencing the level of inflammatory factors and the cell death, including pyroptosis. However, whether M1 and M2 macrophages regulate AKI by secreting exosome remains unknown. In the present study, we isolated the exosomes from M1 and M2 macrophages and used Western blot and enzyme‐linked immunosorbent assay (ELISA) to investigate the effect of M1 and M2 exosomes on cell pyroptosis. miRNA sequencing was used to identify the different miRNA in M1 and M2 exosomes. Luciferase reporter assay was used to verify the target gene of miRNA. We confirmed that exosomes excreted by macrophages regulated cell pyroptosis in vitro by using Western blot and ELISA. miRNA sequencing revealed the differentially expressed level of miRNAs in M1 and M2 exosomes, among which miR‐93‐5p was involved in the regulation of pyroptosis. By using bioinformatics predictions and luciferase reporter assay, we found that thioredoxin–interacting protein (TXNIP) was a direct target of miR‐93‐5p. Further in vitro and in vivo experiments indicated that exosomal miR‐93‐5p regulated the TXNIP directly to influence the pyroptosis in renal epithelial cells, which explained the functional difference between different phenotypes of macrophages. This study might provide new targets for the treatment of sepsis‐induced AKI.
Rapid growth of waste polymers attracts increasing attentions nowadays, and pyrolysis technology is acknowledged as an effective handling way. In this study, waste rigid polyurethane (RPU) was ...selected to conduct thermogravimetric analysis experiments with four different heating rates. Results showed that the thermo-oxidative degradation of RPU presents a two-main-stage process. Subsequently, thermal degradation kinetics were analyzed by model free, model fitting, and distributed activation energy model (DAEM) fitting methods. Isoconversional methods were used to obtain the apparent activation energy. Pyrolysis kinetic parameters were calculated through selected reaction models by model fitting method. Then the experimental kinetic function was obtained, based on which the proper theoretical reaction models were modified by the accommodation function. The best reaction model from the alternative reconstructed functions was optimized for two steps respectively. Distributed activation energy model was firstly introduced to fit the experimental data of RPU pyrolysis. The results of this study have implications concerning kinetic triplet determination method and reaction models modification, especially guiding to waste polymers pyrolysis kinetics and reaction model construction.
•The activation energies of RPU were calculated by multi isoconversional methods.•The Step-1 reaction process was controlled by F1 models, and R2 dominated the Step-2 process.•By accommodating all the proper reaction models, the best reconstructed kinetic functions were obtained.•DAEM was developed to simultaneously fit the TG data from four different heating rates.
One major threat to revealing cultural influences on psychological states or processes is the presence of bias (i.e., systematic measurement error). When quantitative measures are not targeting the ...same construct or they differ in metric across cultures, the validity of inferences about cultural variability (and universality) is in doubt. The objectives of this article are to review what can be done about it and what is being done about it. To date, a multitude of useful techniques and methods to reduce or assess bias in cross-cultural research have been developed. We explore the limits of invariance/equivalence testing and suggest more flexible means of dealing with bias. First, we review currently available established and novel methods that reveal bias in cross-cultural research. Second, we analyze current practices in a systematic content analysis. The content analysis of more than 500 culture-comparative quantitative studies (published from 2008 to 2015 in three outlets in cross-cultural, social, and developmental psychology) aims to gauge current practices and approaches in the assessment of measurement equivalence/invariance. Surprisingly, the analysis revealed a rather low penetration of invariance testing in cross-cultural research. Although a multitude of classical and novel approaches for invariance testing is available, these are employed infrequent rather than habitual. We discuss reasons for this hesitation, and we derive suggestions for creatively assessing and handling biases across different research paradigms and designs.
•Field trials on the use of MICP for wind erosion control of desert soil are conducted.•Soil crusts on loose cohesionless desert soil exist after MICP treatment.•MICP shows pleasurable ecological ...compatibility and long-term sustainability.•MICP is a promising candidate to mitigate wind erosion of desert soils in drylands.
This study examined the potential of microbially induced carbonate precipitation (MICP) in reducing wind erosion of desert soil. Field tests were conducted on artificial mounds and bare sandy land located in Ulan Buh Desert, Ningxia Hui Autonomous Region, China. Results showed that the MICP method could significantly enhance the bearing capacity and wind erosion resistance of the surficial soil through the formation of soil crusts. The optimal cementation solution (containing equimolar urea and calcium chloride) concentration and spraying volume, were 0.2 M and 4 L/m2, respectively. Under this condition, the soil crusts, with a thickness of 12.5 mm and a calcium carbonate (CaCO3) content of 0.57%, remained intact on the surface of man-made mounds after being exposed to a 30 m/s wind for 2 min. For the sandy land, the soil bearing capacity could reach its maximum of 459.9 kPa (as measured with a 6 mm-diameter handheld penetrometer) within three days, and the depth of wind erosion was approximately zero after 30 days of exposure to the local weather conditions. Furthermore, the biocementation method showed its ecological compatibility at the optimal dosage. Scanning electron microscopy (SEM) tests with energy dispersive X-ray (EDX) confirmed the bridge effect of CaCO3 crystals. Longer-term durability of MICP treatment was evaluated, and the results showed that soil bearing capacity and wind erosion resistance of the sandy land was significantly improved over 180 days. These findings suggest that MICP is a promising candidate to protect desert soils from wind erosion.
Abstract
Price reductions take either an integrated form (e.g., a discount shown directly on the price tag) or a non-integrated form (e.g., a discount contained in a coupon sent to consumers and thus ...separate from the price tag). This research examines how non-integrated versus integrated promotions influence choices among vertically differentiated products. Under an integrated promotion (e.g., $10 off) applicable to multiple products (e.g., original list prices: $50 vs. $30), consumers directly compare these products’ post-promotion final prices displayed on their price tags (after a reduction of $10: $40 vs. $20). In contrast, under a non-integrated promotion of the same monetary value, consumers simply compare these products’ original list prices ($50 vs. $30) and neglect their post-promotion final prices, which require calculations. The list prices ($50 vs. $30; relative to the final prices: $40 vs. $20) as a basis for price comparison reduce the perceived price difference between these products. Consequently, a non-integrated promotion (compared to an integrated promotion) increases consumers’ choice of higher-priced products. A series of experiments (N = 5,187) demonstrate this effect and support the final price neglect mechanism. Furthermore, although attenuated, this effect still emerges for price reductions of a smaller magnitude or in a percent-off format.
The development of an efficient catalyst for formic acid electrocatalytic oxidation reaction (FAEOR) is of great significance to accelerate the commercial application of direct formic acid fuel cells ...(DFAFC). Herein, palladium phosphide (PdxPy) porous nanotubes (PNTs) with different phosphide content (i.e., Pd3P and Pd5P2) are prepared by combining the self‐template reduction method of dimethylglyoxime‐Pd(II) complex nanorods and succedent phosphating treatment. During the reduction process, the self‐removal of the template and the continual inside–outside Ostwald ripening phenomenon are responsible for the generation of the one‐dimensional hollow and porous architecture. On the basis of the unique synthetic procedure and structural advantages, Pd3P PNTs with optimized phosphide content show outstanding electroactivity and stability for FAEOR. Importantly, the strong electronic effect between Pd and P promotes the direct pathway of FAEOR and inhibits the occurrence of the formic acid decomposition reaction, which effectively enhances the FAEOR electroactivity of Pd3P PNTs. In view of the facial synthesis, excellent electroactivity, high stability, and unordinary selectivity, Pd3P PNTs have the potential to be an efficient anode electrocatalyst for DFAFC.
Efficient formic acid oxidation reaction (FAEOR) electrocatalyst Pd3P porous nanotubes (PNTs) are synthesized by simple self‐template pyrolysis and phosphating treatment. Benefiting from the abundant defect atoms and excellent self‐stability, Pd3P PNTs reveal outstanding electroactivity and durability for FAEOR. The introduction of phosphorus could effectively improve the FAEOR electroactivity of Pd nanomaterials and simultaneously inhibit FADR, highlighting an efficient strategy for designing a DFAFC anode electrocatalyst.
•Activation energies of XPS and RPU were calculated by multi isoconversional methods.•Pyrolysis models of XPS and RPU are identified and reconstructed.•Pre-exponential factors have the same ...variations with activation energies.•Large amounts of alcohols and ethers are produced during RPU pyrolysis.
The utilization of polymer wastes for volatile fuel production has been considered as a sustainable and environmental-friendly approach for achieving better waste management, pollution protection, and renewable energy security. Polymer pyrolysis, as an ideal method for polymer waste converted into storable fuel, was explored thoroughly in this study from pyrolysis kinetics to evolved gas analysis. Two typical building-used polymer wastes, extruded polystyrene (XPS) and rigid polyurethane (RPU), were selected to conduct a series of thermogravimetry (TG) experiments. Then commonly-used isoconversional methods were employed to calculate the kinetic parameters of the pyrolysis during the whole conversion. Kinetic models of XPS and RPU thermal degradations were identified from nineteen reaction models by Coats-Redfern and masterplots methods. Then accommodation function was employed to adjust the theoretical model for reconstruction. Considering the complexities of RPU component and degradation process, Py-GC/MS was used to identify the volatile product component at 250, 340, and 460 °C, respectively. Results showed that there are large parts of volatile alcohols and ethers escaped during RPU pyrolysis process. The results of this study have implications concerning kinetic triplet determination method and escaped gas analysis during polymer waste pyrolysis process.
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