Compact higher-order(HO)schemes for a new finite difference method,referred to as the Cartesian cut-stencil FD method,for the numerical solution of the convection-diffusion equation in complex shaped domains have been...
详细信息
Compact higher-order(HO)schemes for a new finite difference method,referred to as the Cartesian cut-stencil FD method,for the numerical solution of the convection-diffusion equation in complex shaped domains have been addressed in this *** Cartesian cut-stencil FD method,which employs 1-D quadratic transformation functions to map a non-uniform(uncut or cut)physical stencil to a uniform computational stencil,can be combined with compact HO Pad´e-Hermitian formulations to produce HO cut-stencil *** modified partial differential equation technique is used to develop formulas for the local truncation error for the cut-stencil HO *** effect of various HO approximations for Neumann boundary conditions on the solution accuracy and global order of convergence are *** numerical results for second-order and compact HO formulations of the Cartesian cut-stencil FD method have been compared for test problems using the method of manufactured solutions.
A simple one-pot reaction that serves to functionalize graphite nanosheets(graphene)and single-walled carbon nanotubes(SWNTs)with perfluorinated alkyl groups is *** radical addition of 1-iodo-1H,1H,2H,2H-perfluorodode...
详细信息
A simple one-pot reaction that serves to functionalize graphite nanosheets(graphene)and single-walled carbon nanotubes(SWNTs)with perfluorinated alkyl groups is *** radical addition of 1-iodo-1H,1H,2H,2H-perfluorododecane to ortho-dichlorobenzene suspensions of the carbon nanomaterial is initiated by thermal decomposition of benzoyl ***,UV photolysis of 1-iodo-perfluorodecane serves to functionalize the carbon ***-SWNTs,perfluorododecyl-graphene,and perfluorodecyl-graphene are characterized by infrared(Ir)and raman spectroscopy,X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA),and atomic force microscopy(AFm).The products show enhanced dispersability in CHCl3 as compared to unfunctionalized starting *** advantage of this one-pot functionalization procedure lies in the use of pristine graphite as starting material thereby avoiding the use of harsh oxidizing conditions.
Neuronal necroptosis-an emerging form of regulated cell death associated with neuroinflammatory signaling:Alzheimer’s disease(AD)is characterized by the presence of extracellular amyloid-β(Aβ)plaques and intracellu...
详细信息
Neuronal necroptosis-an emerging form of regulated cell death associated with neuroinflammatory signaling:Alzheimer’s disease(AD)is characterized by the presence of extracellular amyloid-β(Aβ)plaques and intracellular tau neurofibrillary tangles as well as progressive neuronal *** evidence has suggested that prolonged neuroinflammation with increased levels of cytokines,arising from neuronal injury,innate immune responses from glial cells,and peripheral inflammation,leads to neuronal death and AD progression.
Copper-decorated carbon nanotubes(CNTs) have important applications as precursors for ultraconductive copper wires. Tenorite-decorated CNTs(CuO-CNTs) are ideal candidates and are currently developed using laborious pr...
详细信息
Copper-decorated carbon nanotubes(CNTs) have important applications as precursors for ultraconductive copper wires. Tenorite-decorated CNTs(CuO-CNTs) are ideal candidates and are currently developed using laborious processes. For this reason, we have developed a facile and scalable method for the synthesis of CuO-CNTs from copper acetate. It was found that the optimal loading of copper acetate onto the CNTs was 23.1 wt% and that three 1-minute microwave treatments were sufficient for the decomposition of copper acetate to copper oxide. The loading of copper oxide onto the nanotubes was confirmed using X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and thermogravimetric analysis. The materials were characterised using X-ray diffraction and scanning electron microscopy.
Phasormeasurement units(PmUs)are fundamental tools in the applications of modern power systems,where synchronized phasor estimations are *** accuracy and dynamic performance requirements for phasor,frequency,and rate...
详细信息
Phasor measurement units(PmUs)are fundamental tools in the applications of modern power systems,where synchronized phasor estimations are *** accuracy and dynamic performance requirements for phasor,frequency,and rate of change of frequency(rOCOF)estimations are established in the IEEE Std.C37.118.1-2011 along with the IEEE Std.C37.118.1 a-2014,where two PmU performances are suggested:P class filters for applications requiring fast response and m class filters for applications requiring high rejection to aliased *** this paper,a methodology to design new phasor estimators that satisfy the P class and m class requirements in PmUs is *** proposed methodology is based on finite impulse response filters,brick-wall filters,and complex filter design concepts,where frequency range,time performance,harmonic rejection and out-of-band interference requirements are considered in its design.A comparative analysis using the reference model given by the IEEE Std.C37.118.1 is *** results show the effectiveness of the phasor estimators under steady-state and dynamic conditions according to the PmU standard,making them suitable tools for applications in power systems.
In this paper we present a full-geometry Computational Fluid Dynamics (CFD) modeling of air flow distribution from an automotive engine cooling fan. To simplify geometric modeling and mesh generation, different soluti...
详细信息
In this paper we present a full-geometry Computational Fluid Dynamics (CFD) modeling of air flow distribution from an automotive engine cooling fan. To simplify geometric modeling and mesh generation, different solution domains have been considered, the Core model, the Extended-Hub model, and the multiple reference Frame (mrF) model. We also consider the effect of blockage on the flow and pressure fields. The Extended-Hub model simplifies meshing without compromising accuracy. Optimal locations of the computational boundary conditions have been determined for the mrF model. The blockage results in significant difference in pressure rise, and the difference increases with increasing flow rates. results are in good agreement with data obtained from an experimental test facility. Finally, we consider Simplified Fan models which simplifies geometric modeling and mesh generation and significantly reduce the amount of computer memory used and time needed to carry out the calculations. Different models are compared in regards to efficiency and accuracy. The effect of using data from different planes is considered to optimize performance. The effect of blockage on simplified models is also considered.
Silica gel and mCm-41 synthesized mesoporous materials were treated with either oxygen(O_2),hexamethyldisiloxane(HmDSO) and organic vapors like ethanol(Et OH),and acrylonitrile(AN)inductive *** radiofrequency ...
详细信息
Silica gel and mCm-41 synthesized mesoporous materials were treated with either oxygen(O_2),hexamethyldisiloxane(HmDSO) and organic vapors like ethanol(Et OH),and acrylonitrile(AN)inductive *** radiofrequency power for the modification was fixed to 120 W and30 min,assuring a high degree of organic ionization energy in the *** surface properties were studied by infrared spectroscopy(FTIr),scanning electron microscopy,x-ray photoelectron spectroscopy and dynamic light scattering technique was used for characterizing size *** the silica and mCm-41 particles were modified by AN and HmDSO plasma gases,the surface morphology of the particles was changed,presenting another color,size or *** contrast,the treatments of oxygen and Et OH did not affect the surface morphology of both particles,but increased the oxygen content at the surface bigger than the AN and HmDSO plasma *** this study,we investigated the influence of different plasma treatments on changes in morphology and the chemical composition of the modified particles which render them a possible new adsorbent for utilization in sorptive extraction techniques for polar compounds.
It is theorized that enhanced thermal heating may result from exposing single-walled carbon nanotubes (SWNTs) embedded in a conductive host to radiofrequency (rF) electric fields. We examine the rF-induced (13.56...
详细信息
It is theorized that enhanced thermal heating may result from exposing single-walled carbon nanotubes (SWNTs) embedded in a conductive host to radiofrequency (rF) electric fields. We examine the rF-induced (13.56 mHz) heating behaviors of 95% metallic- and semiconducting-enriched SWNTs (m-/s-SWNTs) suspended in aqueous solutions with varying NaC1 molarity (0.001 mm-1 m). The heating effects were only evident for host molarities below 1 mm (equivalent to 0.1 S/m) at which the s-SWNT heating rates dominated those of the m-SWNTs. The heating effects were localized to aligned and aggregated "SWNT ropes" -1 cm in length that formed in suspension, parallel to the electric-field vector, during the rF exposure. For molarities above 1 mm, no enhancements were evident, owing to the large heating effects of the bulk ionic NaC1 suspensions, which were observed in previous studies. Although larger enhancement effects proportional to the host conductivity have been theoretically predicted for m-/s-SWNT suspensions, this was not observed most likely because of the aggregation and screening effects, which diminished the scattered electric field near the m-/s-SWNTs. Our research may further the development of better nanoparticle heating agents for applications such as non-invasive rF-induced cancer hyperthermia.
暂无评论