Dispersion and Pressure Sensitivity of Carbon Nanofiber-Reinforced Polyurethane Cement

Nan Yang; Kexin Zhang; Quansheng Sun

doi:10.3390/app8122375

Dispersion and Pressure Sensitivity of Carbon Nanofiber-Reinforced Polyurethane Cement

Applied Sciences ◽

10.3390/app8122375 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2375 ◽

Cited By ~ 3

Author(s):

Nan Yang ◽

Kexin Zhang ◽

Quansheng Sun

Keyword(s):

Axial Load ◽

Carbon Nanofiber ◽

Critical Value ◽

Variation Coefficient ◽

Pressure Sensitivity ◽

Simple Method ◽

Resistance Variation ◽

Percolation Thresholds ◽

Percolation Zone ◽

Sensitivity Characteristic

The sensitivity of carbon nanofiber polyurethane cement (CNFPUC) was evaluated to determine whether the cement can act as an intelligent reinforcement material. The percolation thresholds at different polymer-to-cement ratios were determined through experimentation. Taking a specific carbon nanofiber (CNF) content of the percolation zone, several CNFPUC mixtures with different poly-ash ratios and silica fume contents were made. They were then sampled from the mixture and poured into a hexahedron CNFPUC test block; the coefficient of variation of resistance and the piezoresistive characteristics under axial load were examined and the blocks were examined by scanning electron microscope. The sensitivity of the CNFPUC mixture was evaluated via the resistance variation coefficient of a sample hexahedron. For different CNF dosages, the critical value of the variation coefficient was used to assess the sensitivity characteristic by fitting the conic curve. These findings may provide a novel and simple method for determining the sensitivity of CNFPUC mixtures.

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The Stability of an Axially–Loaded Continuous Beam

Journal of the Royal Aeronautical Society ◽

10.1017/s0368393100119534 ◽

1955 ◽

Vol 59 (535) ◽

pp. 506-509

Author(s):

A. M. Dobson

Keyword(s):

Axial Load ◽

Classical Method ◽

Complete Solution ◽

Critical Value ◽

Continuous Beam ◽

Independent Variables ◽

A Value ◽

Method Of Solution ◽

Axially Loaded ◽

The Stability

The Classical method of solution of the stability of an axially–loaded continuous beam is by means of the three moments equation, using the Berry Functions, which are functions of the axial load. As the axial load approaches a value equal to the critical value for a pin–jointed beam, the Berry Functions tend to infinity, and the use of the three moments equations —(i. e. treating the end fixing moments as the independent variables)—leads to certain difficulties in the complete solution of the problem.The major difficulty lies in the question of stability. The critical value is determined by the vanishing of the determinant of the coefficients of the fixing moments in the three moments equations. This value could be found by plotting the determinant against end load (c. f. Pippard and Pritchard). However, in a problem involving a large number of bays, the calculation necessary to do this is likely to be considerable, for there may be many branches to the curve.

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Fabrication of highly pressure-sensitive, hydrophobic, and flexible 3D carbon nanofiber networks by electrospinning for human physiological signal monitoring

Nanoscale ◽

10.1039/c8nr08341j ◽

2019 ◽

Vol 11 (13) ◽

pp. 5942-5950 ◽

Cited By ~ 25

Author(s):

Zhiyuan Han ◽

Zhiqiang Cheng ◽

Ying Chen ◽

Bo Li ◽

Ziwei Liang ◽

...

Keyword(s):

Carbon Nanofiber ◽

Physiological Signals ◽

Ultrahigh Pressure ◽

Pressure Sensitivity ◽

Physiological Signal ◽

Pressure Sensitive ◽

Signal Monitoring

A versatile 3D carbon nanofiber network with an ultrahigh pressure-sensitivity is prepared to monitor human physiological signals.

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Increased Mechanical Properties of Carbon Nanofiber Mats for Possible Medical Applications

Fibers ◽

10.3390/fib7110098 ◽

2019 ◽

Vol 7 (11) ◽

pp. 98 ◽

Cited By ~ 8

Author(s):

Trabelsi ◽

Mamun ◽

Klöcker ◽

Sabantina ◽

Großerhode ◽

...

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Cell Growth ◽

Carbon Nanofiber ◽

Thermal Stabilization ◽

Medical Application ◽

Simple Method ◽

Precursor Polymers ◽

Nanofiber Mats ◽

Pan Nanofiber

Carbon fibers belong to the materials of high interest in medical application due to their good mechanical properties and because they are chemically inert at room temperature. Carbon nanofiber mats, which can be produced by electrospinning diverse precursor polymers, followed by thermal stabilization and carbonization, are under investigation as possible substrates for cell growth, especially for possible 3D cell growth applications in tissue engineering. However, such carbon nanofiber mats may be too brittle to serve as a reliable substrate. Here we report on a simple method of creating highly robust carbon nanofiber mats by using electrospun polyacrylonitrile/ZnO nanofiber mats as substrates. We show that the ZnO-blended polyacrylonitrile (PAN) nanofiber mats have significantly increased fiber diameters, resulting in enhanced mechanical properties and thus supporting tissue engineering applications.

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Free-standing supercapacitors from Kraft lignin nanofibers with remarkable volumetric energy density

Chemical Science ◽

10.1039/c8sc04936j ◽

2019 ◽

Vol 10 (10) ◽

pp. 2980-2988 ◽

Cited By ~ 29

Author(s):

Philipp Schlee ◽

Servann Herou ◽

Rhodri Jervis ◽

Paul R. Shearing ◽

Dan J. L. Brett ◽

...

Keyword(s):

Energy Density ◽

Carbon Nanofiber ◽

Kraft Lignin ◽

Free Standing ◽

Simple Method

A very simple method to enhance the low volumetric energy density of free-standing carbon nanofiber electrodes.

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Highly Stretchable Dry Electrode Composited with Carbon Nanofiber (CNF) for Wearable Device

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17816 ◽

2020 ◽

Vol 20 (8) ◽

pp. 4708-4713

Author(s):

Dong-Hyun Beak ◽

Hachul Jung ◽

Dahye Kwon ◽

Seung-A Lee ◽

SongWoo Yoon ◽

...

Keyword(s):

Carbon Nanofiber ◽

Electric Circuit ◽

Strain Sensors ◽

Wearable Device ◽

Electromechanical Property ◽

Simple Method ◽

Dry Electrode ◽

Stretchable Electrode ◽

Highly Stretchable ◽

Electrocardiogram Ecg

In this work, we present a highly stretchable dry electrode composited with carbon nanofiber (CNF) for wearable device by simple method. The fabricated electrodes were assembled with snap connector for connect with electric circuit and sticky polymer for improving adhesion strength on the skin. We evaluated the electrical and mechanical properties depending on the weight % (wt%) and thickness of CNF/elastomer composited stretchable electrode. From the results, the electrical characteristic was improved as increasing concentrations of CNF and their dropping volume. And we evaluated a stretchability and electromechanical property using with cycling test. Through these tests, we have demonstrated that fabricated dry electrode has outstanding stretchability and durability under stretching condition. Finally, electrocardiogram (ECG) was measured with these electrodes. The results of ECG measurement showed similar or larger signal that of commercial wet electrode. Consequently, these results are expected to apply as a wearable device such as a bio-signal measurement and strain sensors.

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Magnetoelastic Buckling of a Thin Plate

Journal of Applied Mechanics ◽

10.1115/1.3601173 ◽

1968 ◽

Vol 35 (1) ◽

pp. 53-58 ◽

Cited By ~ 110

Author(s):

F. C. Moon ◽

Yih-Hsing Pao

Keyword(s):

Magnetic Field ◽

Axial Load ◽

Uniform Magnetic Field ◽

Field Experiments ◽

Equilibrium Configuration ◽

Critical Value ◽

Transverse Magnetic ◽

Field Equations ◽

Magnetostatic Field ◽

Characteristic Values

The instability of a column under axial load is well known. A similar phenomenon is discussed in this paper for a beam-plate in a transverse magnetic field. Experiments show that the beam may buckle (in the sense of an Euler column) when the uniform magnetic field strength reaches a critical value. A mathematical model is proposed with distributed magnetic torques along the plate. A nontrivial adjacent equilibrium configuration satisfying the magnetostatic field equations is shown to exist for characteristic values of the external magnetic field. Results as predicted from this model compare favorably with experiments.

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A simple way for producing holographic filters suitable for image improvement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108271 ◽

1978 ◽

Vol 36 (1) ◽

pp. 226-227

Author(s):

K.-H. Herrmann ◽

E. Reuber ◽

P. Schiske

Keyword(s):

Transfer Functions ◽

Diffraction Order ◽

Lateral Position ◽

Simple Method ◽

Spatial Frequencies ◽

Resolution Electron ◽

Wiener Filters ◽

Image Improvement ◽

Optical Reconstruction ◽

Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

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Rotary Beveling for In Situ Thin-Section Microscopy of Cell Cultures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100099192 ◽

1981 ◽

Vol 39 ◽

pp. 550-551

Author(s):

Dean A. Handley ◽

Jack T. Alexander ◽

Shu Chien

Keyword(s):

Cell Growth ◽

Cell Cultures ◽

Molecular Interactions ◽

Convenient Method ◽

Petri Dish ◽

Simple Method ◽

Thin Section Microscopy ◽

Thin Sectioning ◽

Organic Fluids

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.

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