A computational analysis of magnetized hybrid Darcy-Forchheimer nanofluid flow across a flat surface is presented in this work.For the study of heat and mass transfer aspects viscous dissipation,activation energy,Joul...A computational analysis of magnetized hybrid Darcy-Forchheimer nanofluid flow across a flat surface is presented in this work.For the study of heat and mass transfer aspects viscous dissipation,activation energy,Joule heating,thermal radiation,and heat generation effects are considered.The suspension of nanoparticles singlewalled carbon nanotubes(SWCNTs)and multi-walled carbon nanotubes(MWCNTs)are created by hybrid nanofluids.However,single-walled carbon nanotubes(SWCNTs)produce nanofluids,with water acting as conventional fluid,respectively.Nonlinear partial differential equations(PDEs)that describe the ultimate flow are converted to nonlinear ordinary differential equations(ODEs)using appropriate similarity transformation.The ODEs are dealt with numerically by means of MATLAB’s inbuilt routine function bvp4c.Velocity,temperature,and concentration profiles are explained pictorially whereas Sherwood number,local skin friction coefficient,and Nusselt number values are represented through bar charts.Thermal radiation and activation parameters shows direct impact on flow field.Furthermore,hybrid nanofluid admits a higher magnitude of velocity and temperature than nanofluid,but the concentration profile exhibits the opposite trend.The notable findings of the present investigation have significant applications in heat combustion and cooling chambers,space technology,the ceramics industry,paint and conductive coatings,bio-sensors,and many more.展开更多
Epoxy resin modified by nanometric γ-alumina or multi-walled carbon nanotubes (MCNTs) was prepared with solution mixingmethod, and the wear resistance of the composite was studied. The results show that when an optim...Epoxy resin modified by nanometric γ-alumina or multi-walled carbon nanotubes (MCNTs) was prepared with solution mixingmethod, and the wear resistance of the composite was studied. The results show that when an optimum amount of nanometricalumina or MCNTs is filled in epikote51 (E51), the wear resistance of the composite will increase. When 8 wt pct nanometricγ-alumina is filled in E51, the wear resistance of the composite increases to 230%. When 10% MCNTs is filled in E51, thewear resistance of the composite increases to 226%. When nanometric alumina is filled in, the wear resistance of modifiedepikote51 will increase as the cure temperature is heightened.展开更多
Carbon nanotubes(CNTs) have the ideal structure to be used as templates for nanomaterials, especially for nanowires,and the tungsten nanowire is an important nanomaterial that is used as a strengthening phase. Therefo...Carbon nanotubes(CNTs) have the ideal structure to be used as templates for nanomaterials, especially for nanowires,and the tungsten nanowire is an important nanomaterial that is used as a strengthening phase. Therefore, we have proposed to apply mesoporous CNT(mCNT) as a template to prepare tungsten nanowires. However, the tungsten precursor should fill the hollow tube of mCNT firstly, and very few related studies have been reported. In this paper, we have systematically studied the filling process of ammonium metatungstate(AMT) aqueous solution. The results reveal that owing to the mesopores in the mCNT sidewall, the AMT can be encapsulated into the tube at room temperature(RT) and we can fully fill it without destroying the structure. In addition, vibration and solute concentration are also important factors. Besides,the mesoporous sidewall and hollow tubular core structure of mCNT are prerequisites to realize full filling. Furthermore,tungsten nanowires have been obtained after reduction of AMT in mCNTs.展开更多
It has been well recognized that the development and use of artificial materials with high osteogenic ability is one of the most promising means to replace bone grafting that has exhibited various negative effects.The...It has been well recognized that the development and use of artificial materials with high osteogenic ability is one of the most promising means to replace bone grafting that has exhibited various negative effects.The biomimetic features and unique physiochemical properties of nanomaterials play important roles in stimulating cellular functions and guiding tissue regeneration.But efficacy degree of some nanomaterials to promote specific tissue formation is still not clear.We hereby comparatively studied the osteogenic ability of our treated multiwalled carbon nanotubes(MCNTs)and the main inorganic mineral component of natural bone,nano-hydroxyapatite(nHA)in the same system,and tried to tell the related mechanism.In vitro culture of human adiposederived mesenchymal stem cells(HASCs)on the MCNTs and nHA demonstrated that although there was no significant difference in the cell adhesion amount between on the MCNTs and nHA,the cell attachment strength and proliferation on the MCNTs were better.Most importantly,the MCNTs could induce osteogenic differentiation of the HASCs better than the nHA,the possible mechanism of which was found to be that the MCNTs could activate Notch involved signaling pathways by concentrating more proteins,including specific bone-inducing ones.Moreover,the MCNTs could induce ectopic bone formation in vivo while the nHA could not,which might be because MCNTs could stimulate inducible cells in tissues to form inductive bone better than nHA by concentrating more proteins including specific bone-inducing ones secreted from M2 macrophages.Therefore,MCNTs might be more effective materials for accelerating bone formation even than nHA.展开更多
Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a ...Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a dropping method. The obtained Co3O4 and Co3O4- MCNT were characterized and investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Quantitative analysis of glucose was performed using the amperometric (i–t) method, and plot of current difference versus concentration of glucose was linear in the range of 1.0–122μmol/L, with a linear correlation coefficient (R^2) of 0.9983 and limit of detection (LOD) of 0.28μmol/L. Sensitivity of this sensor was evaluated as 2550μA L mmol^-1 cm^-2. This new sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.展开更多
文摘A computational analysis of magnetized hybrid Darcy-Forchheimer nanofluid flow across a flat surface is presented in this work.For the study of heat and mass transfer aspects viscous dissipation,activation energy,Joule heating,thermal radiation,and heat generation effects are considered.The suspension of nanoparticles singlewalled carbon nanotubes(SWCNTs)and multi-walled carbon nanotubes(MWCNTs)are created by hybrid nanofluids.However,single-walled carbon nanotubes(SWCNTs)produce nanofluids,with water acting as conventional fluid,respectively.Nonlinear partial differential equations(PDEs)that describe the ultimate flow are converted to nonlinear ordinary differential equations(ODEs)using appropriate similarity transformation.The ODEs are dealt with numerically by means of MATLAB’s inbuilt routine function bvp4c.Velocity,temperature,and concentration profiles are explained pictorially whereas Sherwood number,local skin friction coefficient,and Nusselt number values are represented through bar charts.Thermal radiation and activation parameters shows direct impact on flow field.Furthermore,hybrid nanofluid admits a higher magnitude of velocity and temperature than nanofluid,but the concentration profile exhibits the opposite trend.The notable findings of the present investigation have significant applications in heat combustion and cooling chambers,space technology,the ceramics industry,paint and conductive coatings,bio-sensors,and many more.
文摘Epoxy resin modified by nanometric γ-alumina or multi-walled carbon nanotubes (MCNTs) was prepared with solution mixingmethod, and the wear resistance of the composite was studied. The results show that when an optimum amount of nanometricalumina or MCNTs is filled in epikote51 (E51), the wear resistance of the composite will increase. When 8 wt pct nanometricγ-alumina is filled in E51, the wear resistance of the composite increases to 230%. When 10% MCNTs is filled in E51, thewear resistance of the composite increases to 226%. When nanometric alumina is filled in, the wear resistance of modifiedepikote51 will increase as the cure temperature is heightened.
文摘Carbon nanotubes(CNTs) have the ideal structure to be used as templates for nanomaterials, especially for nanowires,and the tungsten nanowire is an important nanomaterial that is used as a strengthening phase. Therefore, we have proposed to apply mesoporous CNT(mCNT) as a template to prepare tungsten nanowires. However, the tungsten precursor should fill the hollow tube of mCNT firstly, and very few related studies have been reported. In this paper, we have systematically studied the filling process of ammonium metatungstate(AMT) aqueous solution. The results reveal that owing to the mesopores in the mCNT sidewall, the AMT can be encapsulated into the tube at room temperature(RT) and we can fully fill it without destroying the structure. In addition, vibration and solute concentration are also important factors. Besides,the mesoporous sidewall and hollow tubular core structure of mCNT are prerequisites to realize full filling. Furthermore,tungsten nanowires have been obtained after reduction of AMT in mCNTs.
基金The authors acknowledge the financial supports from the National Natural Science Foundation of China(No.31771042)Fok Ying Tung Education Foundation(No.141039)+1 种基金State Key Laboratory of New Ceramic and Fine Processing Tsinghua University,Fund of Key Laboratory of Advanced Materials of Ministry of Education(No.2020AML10)International Joint Research Center of Aerospace Biotechnology and Medical Engineering,Ministry of Science and Technology of China,and the 111 Project(No.B13003).
文摘It has been well recognized that the development and use of artificial materials with high osteogenic ability is one of the most promising means to replace bone grafting that has exhibited various negative effects.The biomimetic features and unique physiochemical properties of nanomaterials play important roles in stimulating cellular functions and guiding tissue regeneration.But efficacy degree of some nanomaterials to promote specific tissue formation is still not clear.We hereby comparatively studied the osteogenic ability of our treated multiwalled carbon nanotubes(MCNTs)and the main inorganic mineral component of natural bone,nano-hydroxyapatite(nHA)in the same system,and tried to tell the related mechanism.In vitro culture of human adiposederived mesenchymal stem cells(HASCs)on the MCNTs and nHA demonstrated that although there was no significant difference in the cell adhesion amount between on the MCNTs and nHA,the cell attachment strength and proliferation on the MCNTs were better.Most importantly,the MCNTs could induce osteogenic differentiation of the HASCs better than the nHA,the possible mechanism of which was found to be that the MCNTs could activate Notch involved signaling pathways by concentrating more proteins,including specific bone-inducing ones.Moreover,the MCNTs could induce ectopic bone formation in vivo while the nHA could not,which might be because MCNTs could stimulate inducible cells in tissues to form inductive bone better than nHA by concentrating more proteins including specific bone-inducing ones secreted from M2 macrophages.Therefore,MCNTs might be more effective materials for accelerating bone formation even than nHA.
基金the financial support of this study by the National Natural Science Foundation of China(NSFC, No. 31860468)
文摘Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a dropping method. The obtained Co3O4 and Co3O4- MCNT were characterized and investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Quantitative analysis of glucose was performed using the amperometric (i–t) method, and plot of current difference versus concentration of glucose was linear in the range of 1.0–122μmol/L, with a linear correlation coefficient (R^2) of 0.9983 and limit of detection (LOD) of 0.28μmol/L. Sensitivity of this sensor was evaluated as 2550μA L mmol^-1 cm^-2. This new sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.
