In this study, pyrolysis of low-density polyethylene (LDPE) and LDPE with aluminum (c/LDPE) wastes was carried out with different heating rates (5, 10, 20 degrees c/min) at different temperatures (400, 600, 800 degree...
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In this study, pyrolysis of low-density polyethylene (LDPE) and LDPE with aluminum (c/LDPE) wastes was carried out with different heating rates (5, 10, 20 degrees c/min) at different temperatures (400, 600, 800 degrees c). Product yields of LDPE and c/LDPE wastes were compared, and optimum liquid products were analyzed to utilize as commercial waxes for future use. The properties of pyrolyzed wastes was investigated with proximate, elemental analysis, and TGA. The as-produced liquid from pyrolysis of wastes was characterized by different characteristic tools, such as elemental analyses, Gc-MS analyses, 1H-NMR tests, FT-IR spectra, the density, melting point, and carbon residue to compare commercial waxes. As a result of pyrolysis, the highest liquid product yield was achieved at 800 degrees c with 5 degrees c/min heating rate (85.87%) and at 600 degrees c with 5 degrees c/min heating rate (71.3%) for LDPE and c/LDPE, respectively. The results indicated that the derived liquid products are similar to commercial heavy wax.
c/ce-codoped ZnO nanoparticles immobilized onto multi-walled carbon nanotubes (c/ce-ZnO@MWcNT) were successfully fabricated via the hydrothermal method for degradation of methylene blue (MB) under visible light irradi...
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c/ce-codoped ZnO nanoparticles immobilized onto multi-walled carbon nanotubes (c/ce-ZnO@MWcNT) were successfully fabricated via the hydrothermal method for degradation of methylene blue (MB) under visible light irradiation. The prepared c/ce-ZnO@MWcNT samples were characterized by XRD, XPS, FTIR, FE-SEM, EDX, BET, and diffuse reflectance spectroscopy. The obtained results indicated that the photocatalytic activity of all the MWcNTs-containing samples was higher than those of the bare ZnO and c/ce-codoped ZnO nanoparticles. Besides, the c/ce-ZnO@MWcNT composite with 50 wt% MWcNT showed the highest photocatalytic activity with the MB removal efficiency of 96.5% recorded within 90 min under visible light illumination using 1.0 g/L catalyst dosage at pH of 9 and MB concentration of 30 ppm. The degradation mechanism controlled by the charge transfer process in c/ce-ZnO@MWcNT composite was proposed and discussed in detail. In addition, the long-term-use ability of the photocatalyst was also evaluated through experiments conducted in continuous cycles.
Transpiration cooling system in hypersonic vehicles still remains a challenge due to the limitations of observing permeability and microstructure evolution of porous medium filled with coolant. To tackle this problem,...
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Transpiration cooling system in hypersonic vehicles still remains a challenge due to the limitations of observing permeability and microstructure evolution of porous medium filled with coolant. To tackle this problem, a novel compression-permeation device is designed with high-resolution X-ray tomography system, and then an investigation on permeability evolution mechanism of a c/Sic porous ceramic under pressure is performed using insitu X-ray imaging and the compression-permeation device. The experimental results indicate that the pore-space fluid flow is displayed in terms of three-dimensional streamlines, making the permeability mechanism clear. Meanwhile the porosity along the thickness of ceramic under pressure has been obtained by synchrotron tomography testing, and it is also verified that the porosity of c/Sicceramic fabricated in our research group is basically uniform (>95.4%) along the thickness. Furthermore, we have found the evolution rule for permeability of porous ceramic with water, which depends on the variation of its microstructure under different loads.
Non-specific phospholipase c (NPc) is involved in plant growth, development and stress responses. To elucidate the mechanism by which NPcs mediate cellular functions, here we show that NPc4 is S-acylated at the c term...
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Non-specific phospholipase c (NPc) is involved in plant growth, development and stress responses. To elucidate the mechanism by which NPcs mediate cellular functions, here we show that NPc4 is S-acylated at the c terminus and that acylation determines its plasma membrane (PM) association and function. The acylation of NPc4 was detected using NPc4 isolated from Arabidopsis and reconstituted in vitro. The c-terminal cys-533 was identified as the S-acylation residue, and the mutation of cys-533 to Ala-533 in NPc4 (NPc4(c533A)) led to the loss of S-acylation and membrane association of NPc4. The knockout of NPc4 impeded the phosphate deficiency-induced decrease of the phosphosphingolipid glycosyl inositol phosphoryl ceramide (GIPc), but introducing NPc4(c533A) to npc4-1 failed to complement this defect, thereby supporting the hypothesis that the non-acylated NPc4(c533A) fails to hydrolyze GIPc during phosphate deprivation. Moreover, NPc4(c533A) failed to complement the primary root growth in npc4-1 under stress. In addition, NPc4 in Brassica napus was S-acylated and mutation of the S-acylating cysteine residue of ***4 led to the loss of S-acylation and its membrane association. Together, our results reveal that S-acylation of NPc4 in the c terminus is conserved and required for its membrane association, phosphosphingolipid hydrolysis and function in plant stress responses.
ZrB2 particles were preset to the c-AlSi interface to improve oxidation resistance of c/c preform and adjust the microstructure of the interpenetrated c/c-AlSi composite prepared through pressure infiltration of eutec...
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ZrB2 particles were preset to the c-AlSi interface to improve oxidation resistance of c/c preform and adjust the microstructure of the interpenetrated c/c-AlSi composite prepared through pressure infiltration of eutectic AlSi into a fiber fabric based porous c/c skeleton. Micro-morphology investigations suggested that the AlSi textures were changed from dendritic to petals-like state, and the nano to micro-scale ZrB2 particles were dispersed into AlSi and affected the distribution of Al and Si nearby carbon. Tests demonstrated that c/c-AlSi have slight lower density and thermal expansion coefficient, and higher original compressive strength, while c/c-ZrB2-AlSi composites presented an outstanding strength retention rate after thermal shock. Fracture and micro-morphology indicated that the influence of the preset ZrB2 to the interface of carbon and alloy greatly affected the generation and propagation of cracks, which determined the diverse compression behaviors of the composites before and after thermal shock.
In this study, the effect of the silicon carbide (Sic) matrix content on the mechanical behaviour of a threedimensional needled carbon fibre-reinforced Sic matrix composite (c/Sic) was investigated. The Sic matrix con...
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In this study, the effect of the silicon carbide (Sic) matrix content on the mechanical behaviour of a threedimensional needled carbon fibre-reinforced Sic matrix composite (c/Sic) was investigated. The Sic matrix content was controlled by the infiltration time, and it can be divided into two stages for the evolution of matrix densification, leading to different mechanical responses. In the first stage, with an increase in the Sic matrix content from 12 to 39 vol%, the matrix was filled into a non-woven cloth, leading to an improvement in the loading efficiency of the fibre bundles. Thus, flexural strength and fracture toughness increased sharply from 54 to 218 MPa and 1.3-13.0 MPa m1/2, respectively. As the Sic matrix content increases to 59 vol% in the second stage, the flexural strength and fracture toughness increased to 256 MPa and 15.4 MPa m1/2, respectively. The infiltration ability of the Sic matrix into the non-woven cloth reached the threshold in this stage, and the Sic matrix filled the short-cut web layer, resulting in a slightly increasing tendency of strength and toughness.
carbon fiber (cF) reinforced silicon carbide composites (c/Sic) are high-performance lightweight and highstrength materials, rendering promise as hot-structure materials for high-speed aircraft. However, it is critica...
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carbon fiber (cF) reinforced silicon carbide composites (c/Sic) are high-performance lightweight and highstrength materials, rendering promise as hot-structure materials for high-speed aircraft. However, it is critical to evaluate the performance of c/Siccomposites in simulated aerodynamic thermal environment due to the impure air of wind tunnel. Herein, we analyze the influence of copper contamination on ablation properties of c/ Siccomposites in arc heater. Failure mechanism of c/Siccomposite is revealed by combining experimental results of static oxidation and theoretical evaluation of ablation process under arc heating. Overall, the presence of copper accelerates oxidation and glassification processes of Sic matrix by forming low-temperature compounds. In addition, the influence of fiber orientation on ablation damage of c/Siccomposites is evaluated by combining the distribution of copper-containing phases, airflow distribution, and discrepancies in directionbased thermal conductivity. Results reveal that continuous cF-reinforced micro-zone ceramics resist airflow shear denudation. Furthermore, ablation behavior of needle-punched c/Siccomposites under arc heating is discussed in detail.
Pdxcuy/ccatalysts combinations were employed to cH4 partial oxidation in mild condition using a solid electrolyte reactor-alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor...
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Pdxcuy/ccatalysts combinations were employed to cH4 partial oxidation in mild condition using a solid electrolyte reactor-alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor the oxidation products obtained as methanol, dimethyl ether, methyl formate and potassium formate. It was observed that as the electrical potential of the reactor increases, the generation of products decreases. The best results for conversion of methane into methanol and energy co-generation was obtained from Pd90cu10/c and Pd50cu50/c due to better H2O activation effects and adsorption site for cH4 oxidation.
A combination method of precursor infiltration and pyrolysis (PIP), chemical vapor infiltration (cVI) and liquid silicon infiltration (LSI) was proposed to prepare PIP-Sic modified c/c?Sic brake materials. The Siccer...
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A combination method of precursor infiltration and pyrolysis (PIP), chemical vapor infiltration (cVI) and liquid silicon infiltration (LSI) was proposed to prepare PIP-Sic modified c/c?Sic brake materials. The Sicceramic matrix pyrolyzed by polymethysilane (PMS) homogeneously dispersed in the fiber bundles region, which improved the plough resistance of local c/c region and the wear resistance of c/c?Sic brake materials. When the braking speed rises to 28 m/s, the fluctuation range of friction coefficient was limited to 0.026. The linear wear rate of the as-prepared composites was could be -50% less than that of c/c?Sic, when the braking speed was above 15 m/s (for instance, the wear rate of 1.02 ?m/(side?cycle) at 28 m/s less than 2.02 ?m/(side?cycle) of traditional c/c? Sic). The fading ratio D of coF under wet conditions was -11%. The results showed that introducing PIP-Siccould stabilize the braking process and effectively prolong the service life of c/c?Sic brake materials.
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