Microfluidic inertial switch with high threshold and long pulse-width response

AbstractPLLA microparticles were successfully fabricated via pulsed-DC electrospray. In this study, we investigated the effect of the pulsed voltage characteristics (e.g. pulse frequency, pulse amplitude and pulse width) on the particle’s size. We found that pulse frequency, pulse amplitude, pulse width, and the combinations of these factors had a statistically significant effect on the particle’s size. The process conditions to obtain smaller particles with uniform shape and size are a low pulse frequency, high pulse amplitude, and long pulse width (or a high duty cycle).

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Demonstration of hysteresis in refractoriness of canine ventricular myocardium

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1988.255.6.h1342 ◽

1988 ◽

Vol 255 (6) ◽

pp. H1342-H1348

Author(s):

C. Giorgi ◽

M. Vermeulen ◽

R. Cardinal ◽

P. Savard ◽

R. Nadeau ◽

...

Keyword(s):

Pulse Width ◽

Cycle Length ◽

Ventricular Myocardium ◽

Ventricular Muscle ◽

Cycle Lengths ◽

Long Pulse ◽

Basic Cycle Length ◽

Canine Ventricular Myocardium

The properties and determinants of hysteresis during ventricular effective refractory period (VERP) measurements by an extrastimulus technique were determined in 15 anesthetized open-chest dogs as well as in isolated ventricular muscle (n = 6). VERP was determined both by decreasing the S1-S2 interval and also by increasing S1S2. Hysteresis was then calculated by subtracting the VERP obtained with the decreasing S1S2 from the VERP obtained with the increasing S1S2. The effects of basic cycle length, pulse width, stimulation intensity, and the number of basic drives on VERP and hysteresis were evaluated. VERP was shorter for long pulse width, high stimulation intensities, and shorter basic cycle lengths. These modifications were not associated with significant changes of hysteresis. VERP was shorter during decreasing S1S2 than during increasing S1S2. Hysteresis was greater with 6 basic drive cycles than with 12 (P less than 0.001) in both in vivo and in vitro preparations. The data suggest that 1) hysteresis occurs during VERP measurements; 2) hysteresis is independent of stimulation modality; and 3) hysteresis decreases with the number of basic drive cycles.

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Effect to Online Energy Measurement Device for Long-Pulse Laser by Laser Pulse Width

Chinese Journal of Lasers ◽

10.3788/cjl20103704.1088 ◽

2010 ◽

Vol 37 (4) ◽

pp. 1088-1092 ◽

Cited By ~ 1

Author(s):

魏继锋 Wei Jifeng ◽

关有光 Guan Youguang ◽

周山 Zhou Shan ◽

彭勇 Peng Yong ◽

胡晓阳 Hu Xiaoyang ◽

...

Keyword(s):

Laser Pulse ◽

Pulse Laser ◽

Pulse Width ◽

Energy Measurement ◽

Measurement Device ◽

Laser Pulse Width ◽

Long Pulse

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Spiral pulse generator with high voltage and μs long pulse width

High Power Laser and Particle Beams ◽

10.3788/hplpb20102204.0787 ◽

2010 ◽

Vol 22 (4) ◽

pp. 787-790

Author(s):

方进勇 Fang Jingyong ◽

江伟华 Jiang Weihua ◽

黄文华 Huang Wenhua

Keyword(s):

High Voltage ◽

Pulse Width ◽

Pulse Generator ◽

Long Pulse

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Pulse Characterization of Optically Triggered SiC Thyristors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.717-720.1179 ◽

2012 ◽

Vol 717-720 ◽

pp. 1179-1182 ◽

Cited By ~ 2

Author(s):

Nicolas Dheilly ◽

Gontran Pâques ◽

Sigo Scharnholz ◽

Dominique Planson

Keyword(s):

Pulse Width ◽

Short Pulse ◽

Fabrication Process ◽

Device Structure ◽

Current Pulses ◽

Short Pulse Width ◽

Current Densities ◽

Long Pulse ◽

Pulse Characterization

This paper deals with the pulse capabilities of 4H-SiC optically triggered thyristors. The device structure and the fabrication process are presented. The results of pulse characterizations are shown. Two types of current pulses were used, a short (pulse width of 10 µs) and a long (pulse width of 650 µs). Peak current densities of 17 kA.cm-2 and 4 kA.cm-2 were attained with short and long pulses respectively. The failures and degradation caused by these experiments are also shown in this paper.

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Study on Electrical Performance of a U-Type Microfluidic Acceleration Switch Using Salt Solution as the Sensitive Electrode

Sensors ◽

10.3390/s20247062 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7062

Author(s):

Teng Shen ◽

Yang Chen ◽

Jiaqing Chang ◽

Jianhui Zhang ◽

Xingxing Liu

Keyword(s):

Salt Solution ◽

Liquid Surface ◽

Electrical Performance ◽

Dynamic Threshold ◽

High Threshold ◽

Displacement Curve ◽

Flow Process ◽

Low Viscosity ◽

Inertial Switch ◽

Sensitive Electrode

The threshold of microfluidic inertial switch is excessively dependent on the size of the passive valve structure and the gas–liquid surface energy of working liquid. How to achieve high threshold and anti-high overload using liquid with low viscosity and low surface tension is a challenging work. Based on the designed U-type microfluidic inertial switch, the electrical characteristic of salt solution at microscale as well as the threshold and dynamic electrical performance of switch were studied. The VOF and CSD modules in CFD software were employed to analyze the dynamic flow process, and then the air–liquid surface moving displacement curve was compared by the theoretical model. A self-designed acceleration test platform was utilized to measure the static threshold, dynamic threshold, and anti-high overload of the inertial switch. The results show that the U-type microfluidics inertial switch using salt solution as sensitive electrode has better performance in power connection and anti-high overload. In particular, it also has the ability to achieve a range of dynamic threshold by changing the placement of the contact electrode, which can achieve rapid power on and off.

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Low-Frequency Pulse Width Modulation Design for HVAC Compressors

Volume 3: ASME/IEEE 2009 International Conference on Mechatronic and Embedded Systems and Applications; 20th Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2009-87611 ◽

2009 ◽

Cited By ~ 5

Author(s):

William Burke ◽

David Auslander

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Low Frequency ◽

Air Conditioner ◽

Saturation Power ◽

Compressor Power ◽

Pump Compressor ◽

Long Pulse ◽

Hysteresis Control ◽

Frequency Pulse

This paper discusses the design of low-frequency pulse width modulation for heating ventilation and air conditioning (HVAC) compressors. HVAC units are traditionally controlled using nonlinear control techniques like hysteresis control. Using a very long pulse width, this method can treat an on/off air conditioner or heat pump compressor as a variable input for which traditional linear (or nonlinear) controls can be applied. The key advantage of this method is direct control over the compressor power using tunable saturation. Power control is especially useful when considering load management and real time energy pricing.

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