Frequency tuning allows flow direction control in microfluidic networks with passive features

Lab on a Chip ◽  
2017 ◽  
Vol 17 (9) ◽  
pp. 1552-1558 ◽  
Author(s):  
Rahil Jain ◽  
Barry Lutz
Keyword(s):  
Frequency Tuning ◽  
Flow Direction ◽  
Oscillating Flow ◽  
Resonance Frequencies ◽  
Microfluidic Networks ◽  
Direction Control ◽  
Parallel Resonance

A bidirectional pump created by rectifying oscillating flow driven at engineered fluidic series and parallel resonance frequencies.

scholarly journals Frequency Tuning in Inductive Power Transfer Systems

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 527
Author(s):  
Manuele Bertoluzzo ◽  
Giuseppe Buja
Keyword(s):  
Electric Vehicle ◽  
Power Supply ◽  
Frequency Tuning ◽  
The Other ◽  
Experimental Setup ◽  
Power Transfer ◽  
Inductive Power Transfer ◽  
Resonance Frequencies ◽  
Power Transfer Efficiency ◽  
Inductive Power

Inductive power transfer systems (IPTSs) systems are equipped with compensation networks that resonate at the supply frequency with the inductance of the transmitting and receiving coils to both maximize the power transfer efficiency and reduce the IPTS power sizing. If the network and coil parameters differ from the designed values, the resonance frequencies deviate from the supply frequency, thus reducing the IPTS efficiency. To cope with this issue, two methods of tuning the IPTS supply frequency are presented and discussed. One method is aimed at making resonant the impedance seen by the IPTS power supply, the other one at making resonant the impedance of the receiving stage. The paper closes by implementing the first method in an experimental setup and by testing its tuning capabilities on a prototypal IPTS used for charging the battery of an electric vehicle.

scholarly journals 0408 Flow Direction Control for Nano-Hydraulic Turbine utilizing Waterfalls

2012 ◽  
Vol 2012.49 (0) ◽  
pp. 040801-040802
Author(s):  
Kaika KIMOTO ◽  
Masahiro YAMAZAKI ◽  
Shingo OOIKE ◽  
Shouichiro IIO ◽  
Toshihiko IKEDA
Keyword(s):  
Flow Direction ◽  
Hydraulic Turbine ◽  
Direction Control

scholarly journals Symmetric resonator based tunable epsilon negative near zero index metamaterial with high effective medium ratio for multiband wireless applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md. Moniruzzaman ◽  
Mohammad Tariqul Islam ◽  
Ismail Hossain ◽  
Mohamed S. Soliman ◽  
Md Samsuzzaman ◽  
...  
Keyword(s):  
Refractive Index ◽  
Frequency Tuning ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Effective Medium ◽  
Negative Permittivity ◽  
Wireless Applications ◽  
Compact Size ◽  
Resonance Frequencies ◽  
Electric And Magnetic Fields

AbstractIn this paper, a tuned metamaterial (MTM) consisting of a symmetric split ring resonator is presented that exhibits epsilon negative (ENG), near zero permeability and refractive index properties for multiband microwave applications. The proposed metamaterial is constituted on a Rogers (RT-5880) substrate with 1.57 mm thickness and the electrical dimension of 0.14λ × 0.14λ, where wavelength, λ is calculated at 4.2 GHz. The symmetric resonating patch is subdivided into four equal and similar quartiles with two interconnecting split rings in each quartile. The quartiles are connected at the center of the substrate with a square metal strip with which four tuning metal strips are attached. These tuning metal strips are acted as spacers between four quartiles of the resonator patch. Numerical simulation of the proposed design is executed in CST microwave studio. The proposed MTM provides four resonances of transmission coefficient (S21) at 4.20 GHz, 10.14 GHz, 13.15 GHz, and 17.1 GHz covering C, X and Ku bands with negative permittivity, near zero permeability and refractive index. The calculated effective medium ratio (EMR) is 7.14 at 4.2 GHz indicates its compactness. The resonance frequencies are selective in nature which can be easily tuned by varying the length of the tuning metal stubs. The equivalent circuit of the proposed MTM is modelled in Advanced Design Software (ADS) that exhibits a similar S21 compared with CST simulation. Surface current, electric and magnetic fields are analyzed to explain the frequency tuning property and other performances of the MTM. Compact size, ENG with near zero permeability and refractive index along with frequency selectivity through tuning provides flexibility for frequency selective applications of this MTM in wireless communications.

Barrel-Stave Flextensional Transducers for Sonar Applications

1995 ◽  
Author(s):  
D. F. Jones ◽  
D. J. Lewis ◽  
C. G. Reithmeier ◽  
G. A. Brownell
Keyword(s):  
Frequency Tuning ◽  
Low Cost ◽  
Low Frequency ◽  
Quality Factors ◽  
Active Components ◽  
Sound Sources ◽  
Resonance Frequencies ◽  
Sonar Systems ◽  
Defence Research ◽  
Flextensional Transducers

Abstract Barrel-stave flextensional transducers are low frequency underwater projectors that can be used as active components in long-range sonar systems or as versatile sound sources in oceanographic applications. The advantages offered by this type of flextensional transducer include low frequency, high power, small size, low weight, post-assembly frequency tuning, and low cost due to simplicity in its design and assembly. The construction of three barrel-stave projectors, investigated at the Defence Research Establishment Atlantic (DREA) in recent years, is briefly described. The performance goals for each of these projectors are shown to be consistent with the criteria that distinguish the first three classes in the Brigham-Royster classification scheme for flextensional transducers. Important in-water performance parameters, such as the resonance frequencies, transmitting voltage responses, source levels, mechanical quality factors, and electroacoustic efficiencies, are presented. In addition, these parameters are compared to those of other experimental and commercial barrel-stave flextensional designs.

An Experimental Study of Heat Transfer of a Porous Channel Subjected to Oscillating Flow

2000 ◽  
Vol 123 (1) ◽  
pp. 162-170 ◽  
Author(s):  
H. L. Fu ◽  
K. C. Leong ◽  
X. Y. Huang ◽  
C. Y. Liu
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Surface Temperature ◽  
Steady Flow ◽  
High Speed ◽  
Flow Direction ◽  
Porous Channel ◽  
Oscillating Flow ◽  
Oscillating Flows ◽  
Nusselt Numbers

Experiments have been conducted to study the heat transfer of a porous channel subjected to oscillating flow. The surface temperature distributions for both steady and oscillating flows were measured. The local and length-averaged Nusselt numbers were analyzed. The experimental results revealed that the surface temperature distribution for oscillating flow is more uniform than that for steady flow. Due to the reversing flow direction, there are two thermal entrance regions for oscillating flow. The length-averaged Nusselt number for oscillating flow is higher than that for steady flow. The length-averaged Nusselt number for both steady and oscillating flows increase linearly with a dimensionless grouping parameter k*/kfDe/L1/2Pe*1/2. The porous channel heat sink subjected to oscillating flow can be considered as an effective method for cooling high-speed electronic devices.

scholarly journals A Langasite Crystal Microbalance Coated with Graphene Oxide-Platinum Nanocomposite as a Volatile Organic Compound Sensor: Detection and Discrimination Characteristics

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 334 ◽  
Author(s):  
Ainan Leong ◽  
Tridib Saha ◽  
Varghese Swamy ◽  
Narayanan Ramakrishnan
Keyword(s):  
Graphene Oxide ◽  
Resonance Frequency ◽  
Film Surface ◽  
Series Resonance ◽  
Wave Resonator ◽  
Resonance Frequencies ◽  
Volatile Organic ◽  
Sensitivity And Selectivity ◽  
In Series ◽  
Parallel Resonance

We propose a novel langasite crystal microbalance (LCM) sensor with a graphene-based sensing medium to detect and discriminate volatile organic compounds (VOCs) at room temperature. A thin film of graphene oxide embedded with Pt nanostructures (GO-Pt nanocomposite) was deposited on the electrode surface of the LCM, a thickness-shear acoustic wave resonator. Ethyl acetate, acetic acid, and ethanol were chosen as typical VOCs for this study. Sensitivity and selectivity of coated LCM were investigated for different concentrations of the VOCs by analysing the resonant properties of the sensor. When exposed to VOCs, a negative shift in series resonance frequency was observed due to the mass loading of VOC molecules. Simultaneously, changes in equivalent resistance and parallel resonance frequency of the sensor were also observed due to the interaction of VOCs with charge carriers on the GO-Pt nanocomposite film surface. This dual measurement of both series and parallel resonance frequencies allowed for detection and discrimination of VOCs. Moreover, the high thermal stability of langasite makes the proposed sensor suitable even for harsh environmental conditions.

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