Ejection and Motion Behaviors Simulation for Multi-Jet Electrospinning

2015 ◽  
Vol 645-646 ◽  
pp. 281-286
Author(s):  
Wen Wang Li ◽  
Zhi Wei Luo ◽  
Xiang Wang ◽  
Jian Yi Zheng ◽  
Gao Feng Zheng ◽  
...  
Keyword(s):  
Simulation Model ◽  
Applied Voltage ◽  
Industrial Application ◽  
Good Method ◽  
Repulsive Force ◽  
Maxwell Theory ◽  
Key Factor ◽  
Single Jet ◽  
Stretching Ratio ◽  
Stretching Process

Multi-jet ejection is the key factor to promote the industrial application of electrospinning technology. Simulation model based on Maxwell theory was built up to investigate the ejection and motion behaviors of multi charged jets. The charge Coulomb repulsive force among adjacent jet was introduced into the simulation model, which enhanced the instability motion and promoted the stretching process of charged jets. The stretching ratio of charged jet increased with the increasing of injection distance, applied voltage, distance between spinneret and collector. But stretching ratio of charged jet decreased with the increasing of distance between charged jets. Stretching ratio in multi-jet electrospinning was larger than that in single-jet electrospinning. The maximal stretching ratio of charged jet was larger than 9000 in the nine jets electrospinning mode. This work provided a good method to investigate the controlling technology of multi-jet electrospinning.

Industrial application of a simulation model for high pressure polymerization of ethylene

1996 ◽  
Vol 20 ◽  
pp. S1625-S1630 ◽  
Author(s):  
Antonio Lopez ◽  
Juan J. Pedraza ◽  
Bernardo del Amo
Keyword(s):  
High Pressure ◽  
Simulation Model ◽  
Industrial Application

The Sequential Analysis of Film Deformation Behavior during Successive Biaxial Stretching Process

2013 ◽  
Vol 747 ◽  
pp. 611-614 ◽  
Author(s):  
Yoshiyuki Kushizaki ◽  
Masayoshi Tokihisa ◽  
Hideki Tomiyama ◽  
Toshiro Yamada
Keyword(s):  
Constitutive Equation ◽  
Deformation Behavior ◽  
Draw Ratio ◽  
Sequential Analysis ◽  
Machine Direction ◽  
Material Constants ◽  
Biaxial Stretching ◽  
Experimental Deformation ◽  
Stretching Ratio ◽  
Stretching Process

The deformation behavior of Polypropylene (PP) film during successive biaxial stretching process which consists of machine direction (MD) stretching process with a roll drawing and transverse direction (TD) stretching with a tentering was analyzed sequentially by using a finite element method (FEM). In order to analyze it, stress-strain curves of casted PP film and uni-axially oriented PP film in MD were measured and fitted into the constitutive equation that the authors developed previously, respectively, and then, material constants for both films were obtained. Deformation behavior during successive biaxial stretching were calculated by applying the constitutive equation with the material constants of casted PP film for MD stretching and uni-axially oriented PP film in MD for TD stretching, respectively. Analytical conditions were the draw ratio of 5 for MD analysis and the stretching ratio of 9.5 for TD analysis. The authors also experimentally measured the thickness of film during and after MD and TD stretching using a pilot plant under the same conditions as analytical condition. Calculated results were able to express qualitatively the experimental deformation behavior of PP film such as the neck-in phenomena during MD stretching and the change of film thickness during MD and TD stretching.

Electrohydrodynamic Printing via Spinneret with Conductive Probe

2013 ◽  
Vol 562-565 ◽  
pp. 1155-1160
Author(s):  
Yi Hong Lin ◽  
Guang Qi He ◽  
Hai Yan Liu ◽  
Jin Wei ◽  
Jian Yi Zheng ◽  
...  
Keyword(s):  
Field Strength ◽  
Applied Voltage ◽  
Industrial Application ◽  
Control Level ◽  
Direct Write ◽  
Electrical Field ◽  
Nano Structure ◽  
Electrical Field Strength ◽  
Electrohydrodynamic Printing ◽  
The Stability

Stability jet ejection and precision deposition are the two keys for industrial application of electrohydrodynamic printing. In this paper, inserted conductive probe is utilized to gain stability jet, which would increase the electrical field strength, reduce the back flow, onset and sustaining voltage. Lower applied voltage would enhance the stability of electrospun jet, in which fine jet can be used to direct-write orderly Micro/Nano-structure. With the guidance and constrain of inserted probe, the oscillating angle range of electrohydrodynamic jet is decreased to 3°from 15°, and the width of printed structures is 21μm in average that is much narrower than that printed from spinneret without probe (74μm in average). Spinneret with tip provides a good way to improve the control level of electrohydrodynamic printing, which would accelerate the industrial application of electrohydrodynamic printed Micro/Nano structure.

scholarly journals Uncertainty Analysis of Mixing Efficiency Variation in Passive Micromixers due to Geometric Tolerances

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Irina Stanciu
Keyword(s):  
Simulation Model ◽  
Numerical Study ◽  
Geometric Parameters ◽  
Mixing Efficiency ◽  
Mixing Performance ◽  
Probabilistic Simulation ◽  
Geometric Tolerances ◽  
The Monte Carlo Method ◽  
Key Factor ◽  
Geometric Layout

The geometric layout is the key factor for enhancing the efficiency of the fluid mixing in passive micromixers. Therefore, by adjusting the geometric design and by controlling the geometric parameters, one can enhance the mixing process. However, through any fabrication process, the geometric parameters present slight, inherent variation from the designed values than might affect the performance of the micromixer. This paper proposes a numerical study on the influence of the unavoidable geometric tolerances on the mixing efficiency in passive micromixers. A probabilistic simulation model, based on the Monte Carlo method, is developed and implemented for this purpose. An uncertainty simulation model shows that significant deviations from the deterministic design can appear due to small variations in the geometric parameters values and demonstrates how a more realistic mixing performance can be estimated.

Synthesis and magnetic character of Fe–N/BN nanocomposite

2021 ◽  
Author(s):  
Haiyan Wang ◽  
Changchun Wang ◽  
Lele Song ◽  
Li Liu
Keyword(s):  
Surface Energy ◽  
Saturation Magnetization ◽  
Ball Milling ◽  
Industrial Application ◽  
Magnetic Nanocomposite ◽  
Experimental Conditions ◽  
Reaction Method ◽  
Grain Sizes ◽  
Key Factor

In this work, Fe2N magnetic nanocomposite was synthesized via an in-situ reaction method of ball milling. In this method, Fe and h-BN were used as iron source and nitrogen source, respectively. We found that ball milling could increase the surface energy and make the sample to be amorphous, which is the key factor in synthesizing Fe2N nanocomposite. The as-synthesized nano-sized Fe–N could disperse in the BN matrix uniformly. It is worth noting that we can obtain Fe2N with different grain sizes by controlling the experimental conditions. The saturation magnetization of Fe2N was measured and the value is about 0.03 emu/g. The excellent properties of Fe2N magnetic nanocomposite suggest that Fe2N magnetic nanocomposite could be widely used in industrial application.

Improving Preferred Orientation and Mechanical Properties of the PAN-Based Carbon Fiber Precursors by Using Saturated Steam Stretching Process

2014 ◽  
Vol 789 ◽  
pp. 148-153
Author(s):  
Han Qiu ◽  
Hui Fang Chen
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Testing Machine ◽  
Great Influence ◽  
Saturated Steam ◽  
Tensile Testing Machine ◽  
Pan Fiber ◽  
Increasing Temperature ◽  
Stretching Ratio ◽  
Stretching Process

The saturated steam stretching process of the PAN-based carbon fiber precursors was studied. The orientation,crystallinity, and mechanical properties of the PAN fiber were analyzed by means of X-ray diffraction and XQ-2 tensile testing machine. The results demonstrated that the property of PAN fiber was very sensitive to the temperature, and the tensile strength and orientation degree increased with increasing temperature, which might be attributed to the changes of the super molecular structure. The stretching ratio also had great influence on the crystalline orientation of PAN fiber. Therefore, the temperature and stretching ratio for a certain fiber of the stretching process were matched and limited.

scholarly journals Evaluation of Measures for the Control of Classical Swine Fever Using a Simulation Model

2007 ◽  
Vol 50 (1) ◽  
pp. 92-104 ◽  
Author(s):  
S. Karsten ◽  
G. Rave ◽  
J. Teuffert ◽  
J. Krieter
Keyword(s):  
Simulation Model ◽  
Control Strategy ◽  
Classical Swine Fever ◽  
Good Method ◽  
Control Measures ◽  
Contact Tracing ◽  
Optimal Control Strategy ◽  
Single Measure ◽  
Advantages And Disadvantages ◽  
Council Directive

Abstract. A stochastic and temporal simulation model has been developed to simulate the spread of classical swine fever among herds within a certain area due to farm contacts and local spread. Due to spatial as well as on-farm level heterogeneities in pig production the model allows for the importing of individual farm data. The control measures movement restrictions within protection and surveillance zones, pre-emptive slaughter in proximity to detected farms and animal contact tracing with subsequent culling, applied additionally to stamping-out infected farms, were compared in relation to their effect on the size and the duration of possible epidemics. Additionally, the effects of varying efficiency in contact tracing were analysed. An area with 2986 pig farms and a density of 1.34 farms per km² was generated stochastically for the analysis. When stamping-out infected herds was applied as a single measure, 532 farms became infected on average. The additional application of restriction zones led to a mean epidemic size of 8 infected farms. When all control measures were applied, 5 outbreaks occurred on average. However, the high number of herds depopulated in total curtailed the relative priority of this control strategy. Thus, the presented results point out the necessity to weigh up the advantages and disadvantages in the determination of the optimal control strategy. The simulation model is shown to be a good method to assess the possible consequences of different control measures. The control measures laid down in the EU Council Directive 2001/89/EC (stamping-out infected herds, contact tracing and implementation of restriction zones) seemed to be sufficient for the eradication of classical swine fever epidemics in a region of such farm density. A further reduction in the mean number of outbreaks could be observed when tracing efficiency increased and animal contacts were traced more quickly.

A MEMS Microphone Using Repulsive Force Sensors

2016 ◽  
Author(s):  
Mehmet Ozdogan ◽  
Shahrzad Towfighian
Keyword(s):  
Bias Voltage ◽  
Applied Voltage ◽  
Acoustic Waves ◽  
Capacitive Sensor ◽  
Force Sensor ◽  
Repulsive Force ◽  
Parallel Plates ◽  
Back Volume ◽  
Mems Microphone ◽  
Unit Module

We present a MEMS microphone that converts the mechanical motion of a diaphragm, generated by acoustic waves, to an electrical output voltage by capacitive fingers. The sensitivity of a microphone is one of the most important properties of its design. The sensitivity is proportional to the applied bias voltage. However, it is limited by the pull-in voltage, which causes the parallel plates to collapse and prevents the device from functioning properly. The presented MEMS microphone is biased by repulsive force instead of attractive force to avoid pull-in instability. A unit module of the repulsive force sensor consists of a grounded moving finger directly above a grounded fixed finger placed between two horizontally seperated voltage fixed fingers. The moving finger experiences an asymmetric electrostatic field that generates repulsive force that pushes it away from the substrate. Because of the repulsive nature of the force, the applied voltage can be increased for better sensitivity without the risk of pull-in failure. To date, the repulsive force has been used to engage a MEMS actuator such as a micro-mirror, but we now apply it for a capacitive sensor. Using the repulsive force can revolutionize capacitive sensors in many applications because they will achieve better sensitivity. Our simulations show that the repulsive force allows us to improve the sensitivity by increasing the bias voltage. The applied voltage and the back volume of a standard microphone have stiffening effects that significantly reduce its sensitivity. We find that proper design of the back volume and capacitive fingers yield promising results without pull-in instability.

A method to increase the dynamic deformation of a dielectric elastomer minimum energy structures rotary joint without increase of the voltage amplitude

2019 ◽  
Vol 30 (14) ◽  
pp. 2091-2098
Author(s):  
Shu Wang ◽  
Bo Huang ◽  
David McCoul ◽  
Xinbo Wang ◽  
Jianwen Zhao
Keyword(s):  
Duty Cycle ◽  
Applied Voltage ◽  
Dynamic Deformation ◽  
Minimum Energy ◽  
Dielectric Elastomer ◽  
Voltage Amplitude ◽  
Rotary Joint ◽  
Optimization Principle ◽  
Key Factor ◽  
The Moment

The traditional method to increase the dynamic deformation of a dielectric elastomer actuator is to increase the voltage applied on the dielectric elastomer. Based on the characteristics of dielectric elastomer minimum energy structures, a method to increase the deformation is proposed, which does not increase the applied voltage amplitude. We found that the frequency and duty cycle of the applied voltage will influence the range of deformation strongly, and the moment the power is switched off, [Formula: see text] is a key factor to the deformation range; therefore, the frequency and duty cycle can be optimized to obtain the largest deformation range with an expected vibrational frequency. Two groups of experiments were compared to validate this optimization principle, and the range of deformation with optimized parameters was found to be 1.67 times larger on average than with normal parameters.

scholarly journals Investigating the rheological properties of native plant latex

2014 ◽  
Vol 11 (90) ◽  
pp. 20130847 ◽  
Author(s):  
Georg Bauer ◽  
Christian Friedrich ◽  
Carina Gillig ◽  
Fritz Vollrath ◽  
Thomas Speck ◽  
...  
Keyword(s):  
Wound Healing ◽  
Natural Rubber ◽  
Rheological Properties ◽  
Industrial Application ◽  
Native Plant ◽  
Biological Functions ◽  
Flow Properties ◽  
Key Factor ◽  
Biochemical Components ◽  
Plant Latex

Plant latex, the source of natural rubber, has been of interest to mankind for millennia, with much of the research on its rheological (flow) properties focused towards industrial application. However, little is known regarding the rheology of the native material as produced by the plant, a key factor in determining latex's biological functions. In this study, we outline a method for rheological comparison between native latices that requires a minimum of preparatory steps. Our approach provides quantitative insights into the coagulation mechanisms of Euphorbia and Ficus latex allowing interpretation within a comparative evolutionary framework. Our findings reveal that in laboratory conditions both latices behave like non-Newtonian materials with the coagulation of Euphorbia latex being mediated by a slow evaporative process (more than 60 min), whereas Ficus appears to use additional biochemical components to increase the rate of coagulation (more than 30 min). Based on these results, we propose two different primary defensive roles for latex in these plants: the delivery of anti-herbivory compounds ( Euphorbia ) and rapid wound healing ( Ficus ).

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