A Fluid-Jet Amplifier With Flat Saturation Characteristics

1969 ◽  
Vol 91 (4) ◽  
pp. 734-739 ◽  
Author(s):  
W. S. Griffin
Keyword(s):  
Maximum Output ◽  
Noise Levels ◽  
Output Pressure ◽  
Control Signals ◽  
Maximum Value ◽  
Control Port ◽  
Differential Control ◽  
Percent Decrease

A proportional fluid-jet amplifier has been developed which exhibits flat saturation characteristics and also has reasonable gains, differential output pressures, and noise levels. The amplifier’s output pressure did not drop below 68 percent of its maximum value for any differential control-port pressure in excess of that which caused maximum receiver output. A three-stage, gain block showed less than 3.5 percent decrease in differential output pressure for control signals as high as 200 times their maximum output value.

A Design and Research on GMM Precision Flow Pump

2014 ◽  
Vol 602-605 ◽  
pp. 117-121
Author(s):  
De Hui Liu ◽  
Li Wen Liu ◽  
Gang Tang ◽  
Hong Min Wen ◽  
Quan Guo Lu
Keyword(s):  
Maximum Output ◽  
Output Pressure ◽  
Pump Flow ◽  
Magnetostrictive Materials ◽  
Giant Magnetostrictive Materials ◽  
New Type ◽  
Driving Source ◽  
Flow Pump

A new type of the precision flow pump is developed with the giant magnetostrictive materials as the driving source. Experiment has been conducted to test the performance of the pump with designed key components. The pump as the preloading mechanism, adopting an elastomer instead of a spring, not only simplifies the structure, but also improves the performance of the pump. A design is also made to some key components such as the giant magnetostrictive rod and driving coil. The result of experiment shows that the pump flow resolution records 1 ml/min~400ml/min and the maximum output pressure 0.6 MPa, which means the performance of this kind of pump is superior to ordinary diaphragm pumps.

Triangular Prism and Slit Electrode Pair for ECF Jetting Fabricated by Thick Micromold and Electroforming as Micro Hydraulic Pressure Source for Soft Microrobots

2016 ◽  
Vol 10 (4) ◽  
pp. 470-478 ◽  
Author(s):  
Joon-Wan Kim ◽  
◽  
Thanh V. X. Nguyen ◽  
Kazuya Edamura ◽  
Shinichi Yokota ◽  
...  
Keyword(s):  
Fabrication Process ◽  
Dielectric Fluid ◽  
Electrode Pair ◽  
Hydraulic Pressure ◽  
Triangular Prism ◽  
Maximum Output ◽  
Output Pressure ◽  
Mems Fabrication ◽  
Micromechanical Systems ◽  
Air Compressors

In this paper, we propose a triangular prism and slit electrode pair (TPSE) and its micromechanical systems (MEMS) fabrication process for a novel micropump using electro-conjugate fluid (ECF), which is based on a thick photoresist (KMPR) micromold (≥ 500 μm) and nickel electroforming. ECF is a kind of functional and dielectric fluid. The strong and active jet flow of an ECF is generated between two electrodes surrounded by the ECF when a high direct-current voltage is applied to the electrode pair. The micropumps generated by the ECF jetting can be used as micro hydraulic pressure sources for soft microrobots. By substituting these ECF micropumps for bulky air compressors or hydraulic pumps utilized in soft robots, we can realize advanced soft microrobots in which the driving sources are embedded. An MEMS-based TPSE for an ECF micropump was successfully fabricated by using the proposed MEMS fabrication process. The maximum output pressure without a flow and the flow rate without a load were 24.6 kPa and 27.5 mm3/s, respectively, at an applied voltage of 2 kV. The experimental results show that the MEMS-fabricated TPSE is a good candidate for electrode-type ECF micropumps utilized in various applications of soft microrobots whose pressure sources are embedded inside.

Static and Dynamic Analysis of Selective Leverage System Gear Train

2020 ◽  
Vol 17 (2) ◽  
pp. 1189-1195
Author(s):  
Tiau See Ping ◽  
Salihatun Md Salleh ◽  
Muhammad Al Hafiz Yusoff ◽  
Ainul Husna Mohd Yusoff ◽  
Nasrull Abd Rahman ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Gear Train ◽  
Maximum Output ◽  
Static And Dynamic Analysis ◽  
Dynamic Motion ◽  
Output Torque ◽  
Maximum Value ◽  
Motion Study ◽  
Malleable Cast ◽  
Static Simulation

Nowadays, the mechanical advantage is strongly emphasized in a mechanical system. Therefore, the most modern gearboxes are used to increase the torque without also increasing their output speed while reducing it. In this study, Selective Leverage System (SLS) gear train is generated in Solidworks 2016 and together with dynamic motion study and static simulation analysis. Dynamic motion analysis is performed to provide output speed of SLS gear train. It can be concluded that the gear system runs with unchanged speed (RPM) for input and output which is approximately the same with theoretical value in Selective Leverage System patent. The maximum output torque is evaluated by using theoretical calculation. At every 90° rotation, maximum value of output torque is produced. The results are validated and compared to the analytical value of patent. For static simulation analysis, the stress distribution of T-shaped lever of Selective Leverage System gear train is identified by using composite material compared to the existing gear materials. The static simulation analysis between Aluminium Alloy, S45C Steel, Malleable Cast Iron and Glass Filled Polyamide are compared and composite materials are capable to be used as a material of gear train components instead of current material, S45C Steel for better result.

Effects of catecholamines and potassium on cardiovascular performance in the rabbit

1992 ◽  
Vol 73 (4) ◽  
pp. 1413-1418 ◽  
Author(s):  
D. J. Paterson ◽  
G. J. Blake ◽  
S. P. Leitch ◽  
S. M. Phillips ◽  
H. F. Brown
Keyword(s):  
Blood Pressure ◽  
Cardiac Arrest ◽  
Systolic Blood Pressure ◽  
Healthy Subjects ◽  
Plasma Potassium ◽  
Aortic Flow ◽  
Maximum Output ◽  
Output Pressure ◽  
Cardiovascular Performance ◽  
Exercise Induced

Resting subjects risk cardiac arrest if plasma potassium ([K+]p) is raised rapidly to 7–9 mM, but brief bouts of exhaustive exercise in healthy subjects can give similar [K+]p without causing cardiac problems. We investigated the effects of [K+]p and catecholamines on systolic blood pressure (SBP) and mean aortic flow (MAF) in anesthetized rabbits and on maximum output pressure (MOP) in isolated working rabbit hearts. In six rabbits, hyperkalemia (11.4 +/- 0.4 mM) caused a fall in SBP from 116 +/- 6 to 49 +/- 6 mmHg and in MAF from 373 +/- 30 to 181 +/- 53 ml/min (P < 0.01). Raising [K+]p (11.6 +/- 0.3 mM) with norepinephrine (NE) (1.3 micrograms.kg-1.min-1 iv), however, increased SBP from 108 +/- 7 to 150 +/- 6 mmHg (P < 0.01) and MAF from 347 +/- 42 to 434 +/- 35 ml/min (P < 0.01). In 19 isolated working hearts, perfusion with 8 mM K+ Tyrode and then 12 mM K+ Tyrode reduced MOP from 87 +/- 3 (control 4 mM K+) to 67 +/- 3 (8 mM K+) and 51 +/- 2 cmH2O (12 mM K+) (P < 0.01); 12 mM K+ Tyrode with 0.08 microM NE or epinephrine, however, increased MOP from 67 +/- 6 (in 8 mM K+) to 85 +/- 6 cmH2O (NE) and from 58 +/- 2 to 76 +/- 5 cmH2O (epinephrine) (P < 0.01). Catecholamines may therefore play a key role in protecting the heart from exercise-induced hyperkalemia.

scholarly journals Noise levels of a track-laying tractor during field operations in the vineyard

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Pietro Catania ◽  
Mariangela Vallone
Keyword(s):  
Sound Pressure ◽  
Health And Safety ◽  
Sound Level ◽  
Noise Levels ◽  
Test Conditions ◽  
Maximum Value ◽  
Sound Levels ◽  
Class 1 ◽  
Level Meter ◽  
Almost All

Noise in agriculture is one of the risk factors to be taken into account in the assessment of the health and safety of workers; in particular, it is known that the tractor is a source of high noise. The Italian Low Decree 81/2008 defined the requirements for assessing and managing noise risk identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This paper concerns the analysis of the noise risk arising from the use of a tracklaying tractor during field operations carried out in the vineyard. The objective of this study was to evaluate the noise level that comes close to the ear of the operator driving the tractor measuring the values of equivalent sound level (Leq(A)) and peak sound pressure (LCpk). We considered four options related to the same tractor coupled with the following tools to perform some farming operations: rototilling, chisel plough, flail mowers and vibro farmer. We considered three test conditions: T1 in flat (slope 0%), T2 uphill and T3 downhill (both 30% slope). The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. Each survey lasted 2 minutes, with an interval of measurement equal to 0.5 s. The tests were performed in compliance with the standards ISO 9612 and ISO 9432. The results show that the measured sound levels exceed the limits allowed by the regulations in almost all the test conditions; values exceeding the threshold limit of 80 dB(A) were recorded coming up to a maximum value of 92.8 dB(A) for flail mowers in test T1. When limits imposed by the regulations are exceeded, the operator is obliged to wear the appropriate Personal Protective Equipment.

scholarly journals Experimental Investigation of Double-End Pumped Tm, Ho: GdVO4 Laser at Cryogenic Temperature

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 798
Author(s):  
Yanqiu Du ◽  
Tongyu Dai ◽  
Hui Sun ◽  
Hui Kang ◽  
Hongyang Xia ◽  
...  
Keyword(s):  
Pump Power ◽  
Peak Power ◽  
Continuous Wave ◽  
Maximum Output Power ◽  
Operating Mode ◽  
Maximum Output ◽  
Continuous Wave Laser ◽  
Pump Mode ◽  
Maximum Value ◽  
Output Characteristics

We describe comparatively cryogenically cooled Tm, Ho: GdVO4 lasers with an emission wavelength of 2.05 μm under continuous wave and pulse operating mode. By varying the transmittance of output couplers to be 0.40 for a continuous wave laser, the maximum output power of 7.4 W was generated with a slope efficiency of 43.3% when the absorbed pump power was increased to 18.7 W. For passively Q-switched lasers, the output characteristics were researched through altering pump mode radius. When the pump mode radius focused into the Tm, Ho: GdVO4 center equaled near 600 μm, the peak power was increased to be the maximum value of 9.9 kW at the absorbed pump power of 11.8 W. The pulse energy of 0.39 mJ was achieved at the same absorbed pump power with repetition of 5.7 kHz.

scholarly journals Design and Testing of a Valveless Piezoelectric Pump with Conical Vortex Diodes

2020 ◽  
Vol 306 ◽  
pp. 04003
Author(s):  
Lei Zou ◽  
Kai Li ◽  
Jun Huang
Keyword(s):  
Flow Resistance ◽  
Reverse Flow ◽  
Maximum Output ◽  
Piezoelectric Pump ◽  
Element Analysis ◽  
Output Pressure ◽  
Drive Frequency ◽  
The Difference ◽  
Conical Vortex ◽  
Valveless Piezoelectric Pump

The valveless piezoelectric pump delivers fluid based on the difference of flow resistance of internal tube. In this paper, a vortex diode with conical tangential tube is proposed, which possesses the great characteristic of reverse cut-off, and the analysis of the forward and reverse flow resistance of the conical vortex diode is verified by finite element analysis. Then, a valveless piezoelectric pump with conical vortex diodes as the internal channel is designed, and the prototype is manufactured. The results of the output performance experiment show that the maximum output flow rate of the valveless piezoelectric pump is 10.44 g/min at the drive frequency of 45Hz, and the maximum output pressure is 560 Pa at the drive frequency of 35Hz. The proposal of the valveless piezoelectric pump provides a good reference for more new types of valveless piezoelectric pumps.

scholarly journals Incomplete vesicular docking limits synaptic strength under high release probability conditions

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Gerardo Malagon ◽  
Takafumi Miki ◽  
Van Tran ◽  
Laura C Gomez ◽  
Alain Marty
Keyword(s):  
Synaptic Vesicle ◽  
Synaptic Vesicles ◽  
Calcium Concentration ◽  
Site Occupancy ◽  
Calcium Entry ◽  
Maximum Output ◽  
Calcium Dependent ◽  
Maximum Value ◽  
Voltage Dependent ◽  
External Calcium

Central mammalian synapses release synaptic vesicles in dedicated structures called docking/release sites. It has been assumed that when voltage-dependent calcium entry is sufficiently large, synaptic output attains a maximum value of one synaptic vesicle per action potential and per site. Here we use deconvolution to count synaptic vesicle output at single sites (mean site number per synapse: 3.6). When increasing calcium entry with tetraethylammonium in 1.5 mM external calcium concentration, we find that synaptic output saturates at 0.22 vesicle per site, not at 1 vesicle per site. Fitting the results with current models of calcium-dependent exocytosis indicates that the 0.22 vesicle limit reflects the probability of docking sites to be occupied by synaptic vesicles at rest, as only docked vesicles can be released. With 3 mM external calcium, the maximum output per site increases to 0.47, indicating an increase in docking site occupancy as a function of external calcium concentration.

Research on Piezoelectric Micropump of Combination of Active and Passive Valves

2014 ◽  
Vol 680 ◽  
pp. 271-275
Author(s):  
Jing Sun ◽  
Ping Zeng ◽  
Hai Long Lu
Keyword(s):  
Maximum Output ◽  
Dual Chamber ◽  
Piezoelectric Pump ◽  
Single Chamber ◽  
Output Pressure ◽  
Output Flow ◽  
Active Valve ◽  
Pump Valve ◽  
Output Characteristics ◽  
Single Cavity

In order to improve the output characteristics of active piezoelectric pump valve, Research on dual-chamber tandem piezoelectric pump of combination of active and passive valves is proposed, And dual-chamber tandem piezoelectric pump of combination of active and passive valves is designed and study. The results show that maximum output flow of dual-chamber tandem piezoelectric pump of combination of active and passive valves is 540ml/min, the most output pressure is 27kPa,the maximum output flow of single-cavity active valve piezoelectric pump is 160ml/min;the most output pressure is 9.8kPa, obtained the conclusion that output flow and output pressure of the dual-chamber tandem of combination of active and passive valve is superior to single chamber active valve piezoelectric pump.

scholarly journals A Piezoelectric Resonance Pump Based on a Flexible Support

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 169 ◽  
Author(s):  
Jiantao Wang ◽  
Xiaolong Zhao ◽  
Xiafei Chen ◽  
Haoren Yang
Keyword(s):  
Volume Change ◽  
Structural Parameters ◽  
Peak Voltage ◽  
Output Pressure ◽  
Piezoelectric Resonance ◽  
Flexible Support ◽  
Pump Chamber ◽  
Chamber Height ◽  
Maximum Value ◽  
Resonance Principle

Small volume changes are important factors that restrict the improvement of the performance of a piezoelectric diaphragm pump. In order to increase the volume change of the pump chamber, a square piezoelectric vibrator with a flexible support is proposed in this paper and used as the driving unit of the pump. The pump chamber diaphragm was separated from the driving unit, and the resonance principle was used to amplify the amplitude of the pump diaphragm. After analyzing the working principle of the piezoelectric resonance pump and establishing the motion differential equation of the vibration system, prototypes with different structural parameters were made and tested. The results show that the piezoelectric resonance pump resonated at 236 Hz when pumping air. When the peak-to-peak voltage of the driving power was 220 V, the amplitude of the diaphragm reached a maximum value of 0.43933 mm, and the volume change of the pump was correspondingly improved. When the pump chamber height was 0.25 mm, the output flow rate of pumping water reached a maximum value of 213.5 mL/min. When the chamber height was 0.15 mm, the output pressure reached a maximum value of 85.2 kPa.

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