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- Nanotechnology (15)
- Biotechnology (5)
- Ancient Chinese Mathematics (4)
- E-infinity Theory (El Naschie Space-time theory) (4)
- Electrospinning (3)
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- Homotopy perturbation method (3)
- Variational iteration method (3)
- Encyclopedia (2)
- Exp-function method (2)
- Fractal dimension (2)
- Fractional differential equations (2)
- Nanofiber (2)
- Review article (2)
- ALLOMETRIC SCALING LAWS; E-INFINITY THEORY; ELECTROSPUN NANOFIBERS; BODY-SIZE; BIOLOGY; FIBERS; BRAIN; MODEL (1)
- Air permeability (1)
- Allometrical scaling (1)
- Allometry (1)
- BOMBYX-MORI SILK; SPIDER SILK; MAMMALIAN-CELLS; FIBERS; POLYMER; SCIENCE (1)
- Beaded fiber (1)
- Bombyxmori (1)
- Bubbfil spinning (1)
- Bubble electrospinning (1)
- Bubble electrospinning; blown bubble spinning; nanoscale discontinuous material; nanoporous materials; non-linear differential equation; nanofibers; beads; instability; Chauchy's inequality; non-linear oscillator (1)
- Bubble; surface tension; bubble electrospinning; nanofiber (1)
- Calculus of variations (1)
- Cocoon (1)
- Concentration (1)
- Cryptomeria fortunei (1)
- Duffing equation (1)
- Electrospinning; multiple jets; mass production (1)
Articles 1 - 30 of 44
Full-Text Articles in Engineering
Criterion For An Oscillatory Charged Jet During The Bubble Spinning Process, Ji-Huan He, H.Y. Kong
Criterion For An Oscillatory Charged Jet During The Bubble Spinning Process, Ji-Huan He, H.Y. Kong
Ji-Huan He
The oscillatory diameter of the charged jet during the bubble electrospinning results in beads on the obtained nanofibers. We demonstrate that the applied voltage and the initial flow rate of the jet are the crucial parameters that are necessary to control morphology of the nanofibers. We also find that there is a criterion for production of smooth nanofibers without beads. The theory developed in this paper can be extended to the classical electrospinning and the blown bubble-spinning.
Fractal Harmonic Law And Waterproof/Dustproof, Hai-Yan Kong, Rou-Xi Chen, Ji-Huan He
Fractal Harmonic Law And Waterproof/Dustproof, Hai-Yan Kong, Rou-Xi Chen, Ji-Huan He
Ji-Huan He
The fractal harmonic law admits that the friction between the pure water and the moving surface is the minimum when fractal dimensions of water in Angstrom scale are equal to fractal dimensions of the moving surface in micro scale. In the paper, the fractal harmonic law is applied to demonstrate the mechanism of waterproof/ dustproof. The waterproof phenomenon of goose feathers and lotus leaves is illustrated to verify our results and experimental results agree well with our theoretical analysis.
Fractional Calculus For Nanoscale Flow And Heat Transfer, Hong-Yan Liu, Ji-Huan He, Zheng-Biao Li
Fractional Calculus For Nanoscale Flow And Heat Transfer, Hong-Yan Liu, Ji-Huan He, Zheng-Biao Li
Ji-Huan He
Purpose – Academic and industrial researches on nanoscale flows and heat transfers are an area of increasing global interest, where fascinating phenomena are always observed, e.g. admirable water or air permeation and remarkable thermal conductivity. The purpose of this paper is to reveal the phenomena by the fractional calculus. Design/methodology/approach – This paper begins with the continuum assumption in conventional theories, and then the fractional Gauss’ divergence theorems are used to derive fractional differential equations in fractal media. Fractional derivatives are introduced heuristically by the variational iteration method, and fractal derivatives are explained geometrically. Some effective analytical approaches to fractional …
Local Fractional Variational Iteration Method For Fractal Heat Transfer In Silk Cocoon Hierarchy, Ji-Huan He
Local Fractional Variational Iteration Method For Fractal Heat Transfer In Silk Cocoon Hierarchy, Ji-Huan He
Ji-Huan He
A local fractional equation is established for fractal heat transfer in silk cocoon hierarchy, and the local fractional variational iteration method is adopted to solve the equation analytically. The result can well explain the intriguing phenomenon for pupa's survival at extremes of weather from negative 40 degrees to 50 degrees.
Homotopy Perturbation Method With An Auxiliary Term, Ji-Huan He
Homotopy Perturbation Method With An Auxiliary Term, Ji-Huan He
Ji-Huan He
The two most important steps in application of the homotopy perturbation method are to construct a suitable homotopy equation and to choose a suitable initial guess. The homotopy equation should be such constructed that when the homotopy parameter is zero, it can approximately describe the solution property, and the initial solution can be chosen with an unknown parameter, which is determined after one or two iterations. This paper suggests an alternative approach to construction of the homotopy equation with an auxiliary term; Dufing equation is used as an example to illustrate the solution procedure
Effect Of Temperature On Surface Tension Of A Bubble And Hierarchical Ruptured Bubbles For Nanofiber Fabrication, Ji-Huan He
Ji-Huan He
Polymer bubbles can be used to fabrication of nanofibers using the bubble electrospinning. Temperature is one of the most effective parameters to control the spinning process. Suitable choice of inner and outer temperatures results in a minimal surface tension. A bubble under electronic field will be broken to form daughter bubble cascades, which can be used for nanofiber fabrication.
Review On Fiber Morphology Obtained By Bubble Electrospinning And Blown Bubble Spinning, Ji-Huan He, Hai-Yan Kong, Rui-Rui Yang, Hao Dou, Naeem Faraz, Liang Wang, Chao Feng
Review On Fiber Morphology Obtained By Bubble Electrospinning And Blown Bubble Spinning, Ji-Huan He, Hai-Yan Kong, Rui-Rui Yang, Hao Dou, Naeem Faraz, Liang Wang, Chao Feng
Ji-Huan He
Here we show an intriguing phenomenon in the bubble electrospinning process that the ruptured film might be stripped upwards by an electronic force to form a very thin and long plate-like strip, which might been received in the metal receiver as discontinuous backbone-like wrinkled materials, rather than smooth nanofibers or microspheres. The processes are called the bubble electrospinning. The electronic force can be replaced by a blowing air, and the process is called as the blown bubble spinning. We demonstrate that the size and thickness of the ruptured film are the crucial parameters that are necessary to understand the various …
Effects Of Co2 And Temperature On Biomass Of Parasitic Plants, Ji-Huan He
Effects Of Co2 And Temperature On Biomass Of Parasitic Plants, Ji-Huan He
Ji-Huan He
A general model, based on consistence of metabolic rates of a parasitic plant and its host, is suggested in the paper, that characterizes the effect of atmospheric CO2 concentration and temperature on parasite biomass. The model reveals that the increase of global mean surface temperature and CO2 might lead to an unexpected threat from parasite plants to Cryptomeria fortunei which are more than a millennium year old in Mount Tian-Mu, Zhejiang province, People’s Republic of China. The threat triggers serious disease and death in a very short time. The paper also suggests a reasonable approach to the control of biomass …
The Variational Iteration Method Which Should Be Followed, Ji-Huan He, Guo-Cheng Wu, F. Austin
The Variational Iteration Method Which Should Be Followed, Ji-Huan He, Guo-Cheng Wu, F. Austin
Ji-Huan He
This paper proposes three standard variational iteration algorithms for solving differential equations, integro-differential equations, fractional differential equations, fractal differential equations, differential-difference equations and fractional/fractal differential-difference equations. The physical interpretations of the fractional calculus and the fractal derivative are given and an application to discrete lattice equations is discussed. The paper then examines the acceleration of some iteration formulae with particular emphasis being placed on the exponential Padé approximant that is suggested for solitary solutions and the sinusoidal Padé approximant that is usually used for periodic and compacton solutions. The paper points out that there may not be any physical meaning …
Soliton Perturbation, Ji-Huan He
Soliton Perturbation, Ji-Huan He
Ji-Huan He
Glossary Soliton A soliton is a nonlinear pulse-like wave that can exist in some nonlinear systems. The isolated wave can propagate without dispersing its energy over a large region of space; collision of two solitons leads to unchanged forms, solitons also exhibit particlelike properties. Soliton perturbation theory The soliton perturbation theory is used to study the solitons that are governed by the various nonlinear equations in presence of the perturbation terms. Homotopy perturbation method The homotopy perturbationmethod is a useful tool to the search for solitons without the requirement of presence of small perturbations. In this method, a homotopy is …
Solitons And Compactons, Ji-Huan He, Shun-Dong Zhu
Solitons And Compactons, Ji-Huan He, Shun-Dong Zhu
Ji-Huan He
Article Outline Glossary Definition of the Subject Introduction Solitons Compactons Generalized Solitons and Compacton-like Solutions Future Directions Cross References Bibliography Glossary Soliton A soliton is a stable pulse-like wave that can exist in some nonlinear systems. The soliton, after a collision with another soliton, eventually emerges unscathed. Compacton A compacton is a special solitary traveling wave that, unlike a soliton, does not have exponential tails. Generalized soliton A generalized soliton is a soliton with some free parameters. Generally a generalized soliton can be expressed by exponential functions. 8458 S Solitons and Compactons Compacton-like solution A compcton-like solution is a special …
Biomimic Fabrication Of Electrospun Nanofibers With High-Throughput, Ji-Huan He, Yong Liu, Lan Xu, Jian-Yong Yu, Gang Sun
Biomimic Fabrication Of Electrospun Nanofibers With High-Throughput, Ji-Huan He, Yong Liu, Lan Xu, Jian-Yong Yu, Gang Sun
Ji-Huan He
Spider-spun fiber is of extraordinary strength and toughness comparable to those of electrospun fiber, the later needs a very high voltage (from several thousands voltage to several ten thousands voltages) applied to water-soluble protein “soup” that was produced by a spider, furthermore, its mechanical strength dramatically decreases comparable to spider silk. A possible mechanism in spider-spinning process is given, the distinct character in spider-spinning is that its spinneret consists of millions of nano scale tubes, and a bubble can be produced at the apex of each nano-tube. The surface tension of each bubble is extremely small such that it can …
Effect Of Concentration On Electrospun Polyacrylonitrile (Pan) Nanofibers, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu
Effect Of Concentration On Electrospun Polyacrylonitrile (Pan) Nanofibers, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu
Ji-Huan He
Abstract: An allometrical scaling relationship between the diameter of electrospun nanofiber and solution concentration is established, the scaling exponent differs greatly between different polymers and the same polymer with different molecules or the same molecules with different properties. The diameter of electrospun polyacrylonitrile (PAN) nanofibers increases approximately linearly with solution concentration.
Max-Min Approach To Nonlinear Oscillators, Ji-Huan He
Max-Min Approach To Nonlinear Oscillators, Ji-Huan He
Ji-Huan He
This paper suggests a novel method called max-min method. Maximal and minimal solution thresholds of a nonlinear problem can be easily found, and an approximate solution of the nonlinear equation can be easily deduced using He Chengtian’s interpolation, which has millennia history. Application of the method to nonlinear oscillators is systematically illustrated, illustrating examples show the present technology is very convenient and effective
Comment On ‘He’S Frequency Formulation For Nonlinear Oscillators’, Ji-Huan He
Comment On ‘He’S Frequency Formulation For Nonlinear Oscillators’, Ji-Huan He
Ji-Huan He
Geng and Cai suggested a modified He’s frequency–amplitude formulation for nonlinear oscillators (Geng and Cai 2007 Eur. J. Phys. 28 923–31). We point out the accuracy of both the original one and the modified version depends upon the chosen location point, and so far we have no general rule for the location choice. The method of weighted residuals is suggested to overcome the shortcoming.
An Improved Amplitude-Frequency Formulation For Nonlinear Oscillators, Ji-Huan He
An Improved Amplitude-Frequency Formulation For Nonlinear Oscillators, Ji-Huan He
Ji-Huan He
A brief introduction to amplitude-frequency formulae for nonlinear oscillators is given, an improved one is suggested
Controlling Numbers And Sizes Of Beads In Electrospun Nanofibers, Yong Liu, Ji-Huan He, Jian-Yong Yu, Hong-Mei Zeng
Controlling Numbers And Sizes Of Beads In Electrospun Nanofibers, Yong Liu, Ji-Huan He, Jian-Yong Yu, Hong-Mei Zeng
Ji-Huan He
Abstract BACKGROUND: Electrospinning is a powerful and effective method to produce nanofibers. Beads have been observed widely in electrospun products, but effects of solvents, weight concentrations and salt additives on the number and morphology of beads in the electrospinning process have not been systematically studied. RESULTS: Both theoretical analysis and experimental results show that beads strongly depend upon solvents, weight concentrations and salt additives. Either a suitable weight concentration or a suitable salt additive can completely prevent the occurrence of beads in the electrospinning process; solvents can affect the number of beads and the morphology of electrospun fibers. CONCLUSION: Beads …
Geometrical Approach To Length-Biomass Allometry In Predominantly Bidimensional Seaweeds, Ji-Huan He
Geometrical Approach To Length-Biomass Allometry In Predominantly Bidimensional Seaweeds, Ji-Huan He
Ji-Huan He
Scosati studied experimentally length-biomass allometry in primary producers (vascular plants and unicellular microalgae), and found the allometric exponent (0.5, 95% confidence) differs significantly from the “universal” value, 0.25 suggested by Niklas and Enquist. Here, a geometrical similarity is proposed to elucidate Scosati’s findings.
A New Resistance Formulation For Carbon Nanotubes, Ji-Huan He
A New Resistance Formulation For Carbon Nanotubes, Ji-Huan He
Ji-Huan He
A new resistance formulation for carbon nanotubes is suggested using fractal approach. The new formulation is also valid for other nonmetal conductors including nerve fibers, conductive polymers, and molecular wires. Our theoretical prediction agrees well with experimental observation.
Non-Ionic Surfactants For Enhancing Electrospinability And For The Preparation Of Electrospun Nanofibers, Shu-Qiang Wang, Ji-Huan He, Lan Xu
Non-Ionic Surfactants For Enhancing Electrospinability And For The Preparation Of Electrospun Nanofibers, Shu-Qiang Wang, Ji-Huan He, Lan Xu
Ji-Huan He
Abstract BACKGROUND: Electrospinning is widely used to produce nanofibers; however, not every polymer can be electrospun into nanofibers. To enhance electrospinability, much effort has been made in designing new apparatus, such as vibration-electrospinning, magneto-electrospinning and bubble-electrospinning. RESULTS: A representative non-ionic surfactant, TritonR X-100, is used to enhance electrospinability. The surfactant is added to an electrospun poly(vinyl pyrrolidone) polymer solution, and a dramatic reduction in surface tension is observed. As a result, a moderate voltage is needed to produce fine nanofibers, which are commonly observed during the conventional electrospinning procedure only at elevated voltage. CONCLUSION: The novel strategy produces smaller nanofibers …
An Elementary Introduction To Recently Developed Asymptotic Methods And Nanomechanics In Textile Engineering, Ji-Huan He
An Elementary Introduction To Recently Developed Asymptotic Methods And Nanomechanics In Textile Engineering, Ji-Huan He
Ji-Huan He
This review is an elementary introduction to the concepts of the recently developed asymptotic methods and new developments. Particular attention is paid throughout the paper to giving an intuitive grasp for Lagrange multiplier, calculus of variations, optimization, variational iteration method, parameter-expansion method, exp-function method, homotopy perturbation method, and ancient Chinese mathematics as well. Subsequently, nanomechanics in textile engineering and E-infinity theory in high energy physics, Kleiber's 3/4 law in biology, possible mechanism in spider-spinning process and fractal approach to carbon nanotube are briefly introduced. Bubble-electrospinning for mass production of nanofibers is illustrated. There are in total more than 280 references
Electrospun Nanofibres And Their Applications, Ji-Huan He, Yong Liu, Lu-Feng Mo, Yu-Qin Wan, Lan Xu
Electrospun Nanofibres And Their Applications, Ji-Huan He, Yong Liu, Lu-Feng Mo, Yu-Qin Wan, Lan Xu
Ji-Huan He
This Update covers all aspects of electrospinning as used to produce Nanofibres. It contains an array of colour diagrams, mathematical models, equations and detailed references. It will be invaluable to anyone who is interested in using this technique and also to those interested in finding out more about the subject. Electrospinning is the cheapest and the most straightforward way to produce nanomaterials. Electrospun Nanofibres are very important for the scientific and economic revival of developing countries. Electrospinning was developed from electrostatic spraying and now represents an attractive approach for polymer biomaterials processing, with the opportunity for control over morphology, porosity …
Nano Bubble Dynamics In Spider Spinning System, Ji-Huan He
Nano Bubble Dynamics In Spider Spinning System, Ji-Huan He
Ji-Huan He
A possible mechanism in the spider-spinning process is illustrated and a nanobubble dynamical model is suggested. The spinning system consists of thousands of nano scale spigots and a bubble can be produced at the apex of each nano-spigot. Nano-effect enables the dragline silk to have of extraordinary strength and toughness, while the extremely small surface tension of nanobubbles enables the spider to use an awfully small force during the spinning procedure.
Nonlinear Oscillator With Discontinuity By Parameter-Expansion Method, Shu-Qiang Wang, Ji-Huan He
Nonlinear Oscillator With Discontinuity By Parameter-Expansion Method, Shu-Qiang Wang, Ji-Huan He
Ji-Huan He
The parameter-expansion method is applied to a nonlinear oscillator with discontinuity. One iteration is sufficient to obtain a highly accurate solution, which is valid for the whole solution domain. Comparison of the obtained solution with the exact one shows that the method is very effective and convenient.
Electrospinning: A Promising Technology For Discontinuous And Continuous Nanofibers, Ji-Huan He
Electrospinning: A Promising Technology For Discontinuous And Continuous Nanofibers, Ji-Huan He
Ji-Huan He
No abstract provided.
Exp-Function Method To Solve The Nonlinear Dispersive K(M,N) Equations, Xin-Wei Zhou, Yi-Xin Wen, Ji-Huan He
Exp-Function Method To Solve The Nonlinear Dispersive K(M,N) Equations, Xin-Wei Zhou, Yi-Xin Wen, Ji-Huan He
Ji-Huan He
Some new exact solutions are obtained for the nonlinear dispersive K(m, n) equations using the exp-function method. The results show that the method is straightforward and concise and its applications are promising.
Hierarchy Of Wool Fibers And Fractal Dimensions, Jie Fan, Jun-Fang Liu, Ji-Huan He
Hierarchy Of Wool Fibers And Fractal Dimensions, Jie Fan, Jun-Fang Liu, Ji-Huan He
Ji-Huan He
Wool fiber shows excellent advantages in warmth-retaining and many other practical properties possibly due to its hierarchical structure. Its fractal dimension of wool fiber is calculated which is very close to the Golden Mean, 1.618. The present study might provide a new interpretation for the reason why wool fiber has so many excellent properties
Fatalness Of Virus Depends Upon Its Cell Fractal Geometry, Ji-Huan He
Fatalness Of Virus Depends Upon Its Cell Fractal Geometry, Ji-Huan He
Ji-Huan He
Why do more complex viruses (e.g., HIV, AIDS-virus and SARS coronavirus) tend to be more fatal? The paper concludes that the cell fractal geometry of viruses is the key. This paper also suggests two possible new approaches using nanotechnology and temperature to cure or prevent virus infection
Recent Development Of The Homotopy Perturbation Method, Ji-Huan He
Recent Development Of The Homotopy Perturbation Method, Ji-Huan He
Ji-Huan He
The homotopy perturbation method is extremely accessible to non-mathematicians and engineers. The method decomposes a complex problem under study to a series of simple problems that are easy to be solved. This note gives an elementary introduction to the basic solution procedure of the homotopy perturbation method. Particular attention is oaid to constructing a suitable homotopy equation.
Variational Approach For Nonlinear Oscillators, Ji-Huan He
Variational Approach For Nonlinear Oscillators, Ji-Huan He
Ji-Huan He
We propose a novel variational approach for limit cycles of a kind of nonlinear oscillators. Some examples are given to illustrate the effectiveness and convenience of the method. The obtained results are valid for the whole solution domain with high accuracy. (c) 2006 Elsevier Ltd. All rights reserved.