scholarly journals Effect of bubble size on nanofiber diameter in bubble electrospinning

2016 ◽  
Vol 20 (3) ◽  
pp. 845-848 ◽  
Author(s):  
Zhong-Fu Ren ◽  
Fang-Zhi Kong ◽  
Fei-Yan Wang ◽  
Gui-Fang Hu
Keyword(s):  
Mathematical Model ◽  
Surface Tension ◽  
Theoretical Analysis ◽  
Bubble Size ◽  
Nanofiber Diameter ◽  
Spinning Process ◽  
Experiment Verification

Polymer bubbles are widely used for fabrication of nanofibers. Bubble size affects not only bubble's surface tension, but also fiber's morphology. A mathematical model is established to reveal the effect of bubble size on the spinning process, and the experiment verification shows the theoretical analysis is reliable.

scholarly journals Fabrication of Beltlike Fibers by Electrospinning

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1087 ◽  
Author(s):  
Yan-Qing Liu ◽  
Chun-Hui He ◽  
Xiao-Xia Li ◽  
Ji-Huan He
Keyword(s):  
Surface Tension ◽  
Polyethylene Glycol ◽  
Theoretical Analysis ◽  
Minimal Surface ◽  
Crystallite Size ◽  
Zro2 Nanoparticles ◽  
One Dimensional ◽  
Theoretical Predictions ◽  
Spinning Process ◽  
Moving Jet

Electrospinning is always used to fabricate one-dimensional nanofibers. Cylindrical fibers are formed during the spinning process due to the minimal-surface principle. However, when the moving jet has high rigidity, which can counteract the surface tension for a minimal surface, beltlike fibers can be obtained. Using the Hall–Petch effect, the rigidity of the moving jet can be greatly enhanced by adding nanoparticles. Polyethylene glycol with a nanometric crystallite size of 4 nm and ZrO2 nanoparticles are used as additives in the experiment, a theoretical analysis is carried out, and the theoretical predictions are verified experimentally.

scholarly journals The Muskat problem with surface tension and equal viscosities in subcritical $$L_p$$-Sobolev spaces

2021 ◽  
Author(s):  
Anca-Voichita Matioc ◽  
Bogdan-Vasile Matioc
Keyword(s):  
Mathematical Model ◽  
Surface Tension ◽  
Global Existence ◽  
Sobolev Spaces ◽  
Existence Of Solutions ◽  
Well Posedness ◽  
Global Existence Of Solutions ◽  
Muskat Problem ◽  
The Mathematical Model ◽  
Quasilinear Parabolic

AbstractIn this paper we establish the well-posedness of the Muskat problem with surface tension and equal viscosities in the subcritical Sobolev spaces $$W^s_p(\mathbb {R})$$ W p s ( R ) , where $${p\in (1,2]}$$ p ∈ ( 1 , 2 ] and $${s\in (1+1/p,2)}$$ s ∈ ( 1 + 1 / p , 2 ) . This is achieved by showing that the mathematical model can be formulated as a quasilinear parabolic evolution problem in $$W^{\overline{s}-2}_p(\mathbb {R})$$ W p s ¯ - 2 ( R ) , where $${\overline{s}\in (1+1/p,s)}$$ s ¯ ∈ ( 1 + 1 / p , s ) . Moreover, we prove that the solutions become instantly smooth and we provide a criterion for the global existence of solutions.

Mathematical Model Establishment and Analysis on the Pipe Deformation under External Pressure with the Ovality

2013 ◽  
Vol 760-762 ◽  
pp. 2263-2266
Author(s):  
Kang Yong ◽  
Wei Chen
Keyword(s):  
Mathematical Model ◽  
Theoretical Analysis ◽  
Yield Strength ◽  
Residual Stresses ◽  
Numerical Simulations ◽  
Significant Influence ◽  
External Pressure ◽  
Pipe Diameter ◽  
Axial Loads ◽  
The Stability

Beside the residual stresses and axial loads, other factors of pipe like ovality, moment could also bring a significant influence on pipe deformation under external pressure. The Standard of API-5C3 has discussed the influences of deformation caused by yield strength of pipe, pipe diameter and pipe thickness, but the factor of ovality degree is not included. Experiments and numerical simulations show that with the increasing of pipe ovality degree, the anti-deformation capability under external pressure will become lower, and ovality affecting the stability of pipe shape under external pressure is significant. So it could be a path to find out the mechanics relationship between ovality and pipe deformation under external pressure by the methods of numerical simulations and theoretical analysis.

Attenuation of pulsations in the reciprocating compressor piping system with an elbow-shaped surge tank

2018 ◽  
Vol 233 (5) ◽  
pp. 1677-1689
Author(s):  
Quyang Ma ◽  
Guoan Yang ◽  
Mengjun Li
Keyword(s):  
Mathematical Model ◽  
Theoretical Analysis ◽  
Frequency Analysis ◽  
Transfer Matrix Method ◽  
Piping System ◽  
Pulsation Frequency ◽  
Reciprocating Compressor ◽  
Pressure Pulsations ◽  
Surge Tank ◽  
The Mathematical Model

An elbow-shaped surge tank is proposed to suppress the pressure pulsations. The transfer matrix method was developed and the mathematical model was established to predict the distribution of pressure pulsations in the piping system (on which a surge tank was already installed) with an elbow-shaped surge tank. Simulation work of the whole piping system was performed. The results show that the elbow-shaped surge tank has good performance to attenuate the pressure pulsations. The frequency analysis shows that the amplitude for the first pulsation frequency is attenuated to a low level. The impulse response was analyzed to examine the efficiency of suppressing pulsations by using the suppressor. The theoretical analysis showed that there exists the optimal suppression performance when setting the distance between the elbow-shaped surge tank and the existing one. Meanwhile, modifying the ratio of length to diameter with a fixed surge volume could also impact the pressure pulsations. The analysis results can be used as a reference in designing and installing the elbow-shaped surge tank.

A Mathematical Model for Rotor-Spun Composite Yarn Spinning Process

2009 ◽  
Vol 80 (6) ◽  
pp. 487-490 ◽  
Author(s):  
Rui-Hua Yang ◽  
Shan-Yuan Wang
Keyword(s):  
Mathematical Model ◽  
Composite Yarn ◽  
Spinning Process

scholarly journals Theoretical Analysis and Adaptive Synchronization of a 4D Hyperchaotic Oscillator

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
T. Fonzin Fozin ◽  
J. Kengne ◽  
F. B. Pelap
Keyword(s):  
Mathematical Model ◽  
Adaptive Control ◽  
Theoretical Analysis ◽  
Electronic Circuit ◽  
Adaptive Synchronization ◽  
Uncertain Parameters ◽  
Exponential Nonlinearity ◽  
Dynamical Properties ◽  
Hyperchaotic Systems ◽  
Good Agreement

We propose a new mathematical model of the TNC oscillator and study its impact on the dynamical properties of the oscillator subjected to an exponential nonlinearity. We establish the existence of hyperchaotic behavior in the system through theoretical analysis and by exploiting electronic circuit experiments. The obtained numerical results are found to be in good agreement with experimental observations. Moreover, the new technique on adaptive control theory is used on our model and it is rigorously proven that the adaptive synchronization can be achieved for hyperchaotic systems with uncertain parameters.

scholarly journals Multiple-Jet Needleless Electrospinning Approach via a Linear Flume Spinneret

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2052 ◽  
Author(s):  
Liang Wei ◽  
Chengkun Liu ◽  
Xue Mao ◽  
Jie Dong ◽  
Wei Fan ◽  
...  
Keyword(s):  
Process Parameters ◽  
Applied Voltage ◽  
Mass Production ◽  
Solution Concentration ◽  
Average Error ◽  
High Quality ◽  
Needleless Electrospinning ◽  
Nanofiber Diameter ◽  
Multiple Jets ◽  
Spinning Process

There is a great limitation to improving the quality and productivity of nanofibers through the conventional single-needle method. Using needleless electrospinning technology to generate multiple jets and enhance the productivity of nanofibers has attracted lots of interest for many years. This study develops a novel linear flume spinneret to fabricate nanofibers. Multiple jets with two rows can be formed simultaneously on the surface of the spinneret. The solution concentration has a significant impact on the average nanofiber diameter compared with applied voltage and collection distance. The effects of different spinning process parameters on the productivity of nanofibers are investigated. High-quality nanofibers with small nanofiber diameter and error can be fabricated successfully. The average nanofiber diameter is 108 ± 26 nm. The average error is 24%. The productivity of nanofibers can reach 4.85 ± 0.36 g/h, which is about 24 times more than that of the single-needle method. This novel linear flume spinneret needleless electrospinning technology exhibits huge potential for mass production of nanofibers in the field of industrialization.

Motion Control of an Electromechanical Micro Robot

2020 ◽  
Vol 63 (6) ◽  
pp. 57-65
Author(s):  
Ruzil Safiullin ◽  
Keyword(s):  
Mathematical Model ◽  
Theoretical Analysis ◽  
Motion Control ◽  
Elastic Element ◽  
Human Life ◽  
Robotic Systems ◽  
System Of Equations ◽  
Functional Modules ◽  
Innovative Technologies ◽  
Micro Robot

Currently, the development of innovative technologies in the field of electromechanics are microelectrome-chanical systems. They are widely used both in various industries and in domestic conditions of human life. An algorithm and a mathematical model of the design of an electromechanical composite microrobot have been developed. A system of equations of mechanics and electrodynamics was used to describe its metrological char-acteristics. By solving this system of equations, a theoretical analysis of the operation of its engine with a spiral secondary elastic element is carried out. Using the mechatronic approach, the buoyancy and coordination of its functional modules are studied. The results of this article will be useful for engineers involved in the design and operation of micro robots using robotic systems in the fields of biotechnology and biomechanics.

A mathematical model for the wet-spinning process

1993 ◽  
Vol 4 (4) ◽  
pp. 341-360 ◽  
Author(s):  
H. Ockendon ◽  
E. L. Terrill
Keyword(s):  
Mathematical Model ◽  
Fluid Flow ◽  
Hydrodynamic Force ◽  
Wet Spinning ◽  
Fluid Inertia ◽  
Spreading Process ◽  
Characteristic Ratio ◽  
Spin Bath ◽  
Spinning Process ◽  
Two Parameters

A mathematical model for the hydrodynamic flow and fibre deflections in a wet-spinning process is presented. The model is characterized by two parameters: α which is a characteristic ratio of the hydrodynamic force to the tension force acting on a fibre, and β which is a characteristic ratio of the fibre drag to the fluid inertia. The model is applied to three situations: (i) the spin bath of the process where α ≪ 1 and β ≫ 1, (ii) the preheat bath where α is order 1 and β ≫ 1, (iii) a fibre spreading process where α is order 1 and β is order 1 or smaller. In each case, analytical results are obtained for the fluid flow and fibre deflections and compared with experiment.

Fractional Order Modeling and Analysis of Buck-Boost Converter

2015 ◽  
Vol 789-790 ◽  
pp. 842-848
Author(s):  
Li Feng Yi ◽  
Kai Ru Zhang ◽  
Jun Liu
Keyword(s):  
Mathematical Model ◽  
Theoretical Analysis ◽  
Fractional Calculus ◽  
Simulation Model ◽  
Fractional Order ◽  
Theoretical Foundation ◽  
Boost Converter ◽  
Modeling And Analysis ◽  
Simulation Results ◽  
Conduction Mode

Considered the theoretical foundation of fractional order, the fractional mathematical model of the Buck-Boost converter in continuous conduction mode operation is built and analyzed in theory. Based on the improved Oustaloup fractional calculus for filter algorithm, the simulation model is framed by using the Matlab/Simulink software. And the simulation results are compared with that of integer order. It proves the correctness of the fractional order mathematical model and the theoretical analysis.

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