With the growing interest in cell-based regenerative therapies for skeletal muscle injuries, there is a critical need for a microcarrier strategy specifically designed for superior functioning of myoblasts. Monodisper...
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With the growing interest in cell-based regenerative therapies for skeletal muscle injuries, there is a critical need for a microcarrier strategy specifically designed for superior functioning of myoblasts. Monodisperse porous poly (L-lactide-co-e-caprolactone) (PLCL) microcarriers with precisely controlled diameters were thus developed using microfluidics to explore their effect on differentiation performance of mouse skeletal myoblasts (C2C12 cells). A capillary microfluidic device was designed with varying parameters to fabricate four representative sets of microspheres with diameters of 177 mu m, 270 mu m, 355 mu m, and 472 mu m. C2C12 cells were cultured on these microspheres, and their adhesion and viability were assessed. Myogenic differentiation ehaviour of these cells was evaluated by specific gene expression and myosin heavy chain (MHC) staining. Inflammatory response of macrophages to these microcarriers was assessed to qualify their suitability for muscle repair. Notably, microcarriers of 472 mu m exhibited the optimal performance in promoting myogenic differentiation of C2C12 cells. The expressions of myogenic differentiation markers MYOG, Desmin, and MYH2 were significantly enhanced on the 472 mu m group, showing respective increases of 2.41-fold, 2.15-fold, and 6.87-fold compared to those of the 177 mu m group. Moreover, the formation of long myotubes distributed in a global domain was observed on the 472 mu m group with a fusion index nearly three times as high as that on the 177 mu m group. These microcarriers could effectively inhibit the expression of pro-inflammatory factors IL-6, TNF-alpha and IL-18 by macrophages in a high M1 polarization environment. The results offer a microfluidic based solution for in vitro engineering of injectable constructs for muscle repair and regeneration.
Carbon materials have aroused wide attention in the field of electromagnetic wave absorption because of their advantages of good electrical conductivity, low density and adjustable structure. To obtain enhanced perfor...
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Carbon materials have aroused wide attention in the field of electromagnetic wave absorption because of their advantages of good electrical conductivity, low density and adjustable structure. To obtain enhanced performance of electromagnetic wave absorption, the elaborate design of structures for carbon materials has become essential. In this work, the nitrogen-doped and large diameter carbon nanotubes modified with cobalt nanoparticles (M-Co/C-CNTs) composites were successfully prepared by adsorption and carbonization of the gases generated by organic matter pyrolysis. It is concluded that the enhanced conduction loss and polarization loss are attributed to the interfacial electronic engineering induced by the sensibly loaded cobalt nanoparticles and nitrogen doping. As a result, the samples achieved a broad effective absorption bandwidth of 4.56 GHz, and a strong reflection loss of -52.2 dB with a thin thickness of 2.1 mm. This work proposes a tailored way to fabricate the large diameter carbon nanotube composites and enhance electromagnetic wave absorption through novel structural modulation. (c) 2022 Elsevier Inc. All rights reserved.
The high penetration level of intermittent renewable power necessitates the crucial requirement for combined heat and power systems to possess both high efficiency and flexibility. However, the heat-controlled operati...
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In this work, monolith and packing structures with different particle shapes (cylinder, sphere, trilobe and Raschig ring) are compared to boost selective catalytic reduction (SCR) of NO reaction. The three-dimension s...
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In this work, monolith and packing structures with different particle shapes (cylinder, sphere, trilobe and Raschig ring) are compared to boost selective catalytic reduction (SCR) of NO reaction. The three-dimension structureresolved reactor model is established to evaluate the influence of mass transfer and NO reaction performance in different industrial applications. The simulation results show that monolithic catalysts shift from transition regime to reaction-controlled regime, while the cylinder-resolved catalysts shift from diffusion-controlled regime to transition regime as the reaction temperature decreases from 240 to 160 degrees C for SCR of NO. The monolithic catalyst with excellent mass transfer capacity and the catalyst with cylinder packing structure with high bulk density exhibit highest NO removal efficiency in the coking plant (-240 degrees C) and boiler system (-160 degrees C), respectively. The catalyst with Raschig ring packing structure exhibits the highest NO removal efficiency in the waste incineration plant (-200 degrees C) due to the compromise of reaction-diffusion behavior. A strategy of catalyst structures selection for SCR of NO reaction at different industrial applications based on the reaction-diffusion interaction is proposed, which could shed new light on boosting selective catalytic reduction of NO reaction.
This research proposes a novel type of variable stiffness tuned particle damper(TPD)for reducing vibrations in boring *** TPD integrates the developments of particle damping and dynamical vibration absorber,whose freq...
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This research proposes a novel type of variable stiffness tuned particle damper(TPD)for reducing vibrations in boring *** TPD integrates the developments of particle damping and dynamical vibration absorber,whose frequency tuning principle is established through an equivalent theoretical *** on the multiphaseflow theory of gas-solid,it is effective to obtain the equivalent damping and stiffness of the particle *** dynamic equations of the coupled system,consisting of a boring bar with the TPD,are built by Hamilton’s *** vibration suppression of the TPD is assessed by calculating the amplitude responses of the boring bar both with and without the TPD by the Newmark-beta ***,an improvement is proposed to the existing gas-solid flow theory,and a comparative analysis of introducing the stiffness term on the damping effect is *** parameters of the TPD are optimized by the genetic algorithm,and the results indicate that the optimized TPD effectively reduces the peak response of the boring bar system.
Coarse-grained discrete element methods (CGDEM) have received much attention due to their effective reduction of computational effort. However, compared to discrete element methods (DEM), coarse-grained discrete eleme...
Coarse-grained discrete element methods (CGDEM) have received much attention due to their effective reduction of computational effort. However, compared to discrete element methods (DEM), coarse-grained discrete element methods exhibit lower accuracy in modeling rough, inelastic spherical particles. This is partly because conventional coarse-graining strategies focus only on energy dissipation due to inelasticity. In this article, the impact of particle rotational inertia is incorporated into the translational energy dissipation in inter-particle collisions. A new formula for calculating the normal recovery coefficient is derived according to the strategy that dissipation in coarse-grained models is equal to real particles. The validation was conducted in both a bubbling bed and a spout-fluid bed. It turns out that collision modeling, which considers friction and roughness dissipation (CMF/R), provides better accuracy than CGDEM with the traditional coarsening strategy. Notably, in the 0.15 m height of the spout-fluid bed, CMF/R model shows a smaller relative error compared to DEM simulation experiments. The accuracy and versatility of the new model in calculating normal recovery coefficients were verified by the simulation results.
The intrinsic electrochemical activity and active sites of the battery-like electrode in supercapacitors originate from efficient charge transfer at the interface. A seamless all-carbon graphdiyne layer on CoNi2S4 yol...
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engineering multifunctional smart separators are important for the ongoing pursuit of fast-charging and safe batteries. Herein, a novel nanofibrous covalent organic framework (COF) based separator with well-designed h...
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engineering multifunctional smart separators are important for the ongoing pursuit of fast-charging and safe batteries. Herein, a novel nanofibrous covalent organic framework (COF) based separator with well-designed hierarchical porous channels is fabricated to effectively regulate mass transport for fast-charging and thermally stable lithium metal batteries (LMBs). Such a hierarchical porous separator consists of electrospun polyacrylonitrile nanofibers with macroporous channels (average diameter of 323 nm) and mesoporous channels (approximate to 7 nm) created between amide-group-bonded COF nanoparticles with intrinsic 1.6 nm lithiophilic microporous channels (PAN/AM-COF). Computational fluid dynamics and density functional theory calculations demonstrate that PAN/AM-COF can simultaneously facilitate high-speed and selective transport of Li+, as well as homogeneous deposition of Li, achieving high conductivity (3.33 mS cm-1) and high Li+ transference number (0.79). As a result, Li || LFP full cell with PAN/AM-COF displays superior cycling stability at 10 C with an acceptable capacity attenuation (0.037% per cycle) over 1000 cycles. Moreover, when operating under an extreme temperature of 100 degrees C, the Li || LFP full cell with PAN/AM-COF can still operate stably for 300 cycles at 30 C, highlighting its potential processing scalability for ultrafast-charging energy storage systems. This study gives insights into designing functional separators for fast-charging LMBs. Nanofibrous covalent organic framework-based separators with well-designed hierarchical porous channels and thermal stability are developed to effectively regulate mass transport for achieving rapid and uniform lithium-ions transport. The assembled lithium metal batteries with a high capacity of 97.2 mAh g-1 deliver 300 cycles under 30 C at the temperature of 100 degrees C. image
The dual-percolation polybutene-1 (PB)/poly(ethylene-co-octene) (POE)/carbon nanotube (CNT) composite foams with lightweight, high conductivity, and high-efficiency EMI shielding performance were successfully prepared...
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The dual-percolation polybutene-1 (PB)/poly(ethylene-co-octene) (POE)/carbon nanotube (CNT) composite foams with lightweight, high conductivity, and high-efficiency EMI shielding performance were successfully prepared via melt blending followed by supercritical carbon dioxide (sc-CO2) foaming. The CNTs' selective location in the PB phase of PB/POE/CNT composites was verified based on the kinetic/thermodynamic predictions and scanning electron microscopy observations. The dual percolation structure and porous microstructure of composites affecting the electrical conductivity and EMI shielding property were carefully evaluated. Owning to the bimodal porous structure of dual-percolation composite foams, in which large pores contributed to increasing porosity and small pores dedicated to maintaining the connectivity in conductive networks, the high void fraction and high conductivity were simultaneously achieved. The electromagnetic interference (EMI) shielding performance showed that the foamed PB/POE/CNT composites with 1.4 vol % CNTs loading displayed a 71% decrease in density, 43.2% increase in absorptivity, 41.1% increase in EMI shielding effectiveness (SE), and 76.4% increase in specific EMI SE, in comparation with the solid PB/POE/CNTs loaded with 1.6 vol % CNTs. Moreover, the foamed PB/POE/CNT composites with a 3.3 vol % CNT loading achieved a high EMI SE of 22.4 dB, satisfying the requirements of commercial EMI shielding materials (>= 20 dB).
The flexibility of coal-fired power plants is urgently required to accommodate high penetration of renewable powers. Quantitatively analyzing thermodynamic characteristics of single- and double- reheat boilers could p...
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The flexibility of coal-fired power plants is urgently required to accommodate high penetration of renewable powers. Quantitatively analyzing thermodynamic characteristics of single- and double- reheat boilers could provide meaningful information to enhance the flexibility of double-reheat boilers. In this study, the single- and double- reheat boiler models were developed and validation. The thermodynamic characteristics of the single-and double- reheat boilers under off-design working conditions and during transient processes are compared from the perspective of energy and exergy. Results show that the heat absorption and exergy storage of reheaters in the double-reheat boiler is similar to 1.4 and similar to 2.0 times those of the single-reheat boiler, respectively. The response time of the double-reheat boiler is similar to 400 s longer than that of the single-reheat boiler. The exergy storage change takes as high as 40% of the input exergy change that is caused by the coal feeding rate change in the double-reheat boiler, but only 25% in the single-reheat boiler. This work is expected to provide some detailed guidance of the flexible and efficient operation of double-reheat units.
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