scholarly journals Electrostatically Tunable Nanomechanical Shallow Arches

2017 ◽  
Author(s):  
Syed N. R. Kazmi ◽  
Amal Z. Hajjaj ◽  
Pedro M. F. J. Costa ◽  
Mohammad I. Younis
Keyword(s):  
High Frequency ◽  
Room Temperature ◽  
Silicon On Insulator ◽  
Frequency Range ◽  
Shallow Arches ◽  
High Tunability ◽  
Band Pass ◽  
Dc Bias ◽  
Silicon Based ◽  
Good Agreement

We report an analytical and experimental study on the tunability of in-plane doubly-clamped nanomechanical arches under varied DC bias conditions at room temperature. For this purpose, silicon based shallow arches are fabricated using standard e-beam lithography and surface nanomachining of a highly conductive device layer on a silicon-on-insulator (SOI) wafer. The experimental results show good agreement with the analytical results with a maximum tunability of 108.14% for 180 nm thick arch with a transduction gap of 1 μm between the beam and the driving/sensing electrodes. The high tunability of shallow arches paves the ways for highly tunable band pass filtering applications in high frequency range.

ANALYSIS OF OPERATIONAL TRANSCONDUCTANCE AMPLIFIER FOR APPLICATION IN GHz FREQUENCY RANGE

2004 ◽  
Vol 14 (03) ◽  
pp. 690-695
Author(s):  
A. GHORI ◽  
P. GHOSH
Keyword(s):  
High Frequency ◽  
Current Mode ◽  
Silicon On Insulator ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Operational Transconductance Amplifier ◽  
Frequency Range ◽  
Pass Filter ◽  
Transconductance Amplifier ◽  
Band Pass

Operational Transconductance Amplifier (OTA) is an excellent current mode device suited very well for VLSI implementation. In this contribution we report realization of OTA using Silicon-On-Insulator (SOI) structure based MOSFETs and compared them to OTA designed with bulk MOSFET. SOI based OTA outperformed bulk MOSFET OTA giving close to 10 GHz improvement in high frequency f T . A band-pass filter was implemented with SOI based OTA with a center frequency of 7 GHz and a bandwidth of 480 kHz.

High Frequency Dielectric Response of the Ionic Liquid N-Methyl-N-ethylpyrrolidinium Dicyanamide

2007 ◽  
Vol 60 (1) ◽  
pp. 6 ◽  
Author(s):  
Simon Schrödle ◽  
Gary Annat ◽  
Douglas R. MacFarlane ◽  
Maria Forsyth ◽  
Richard Buchner ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
High Frequency ◽  
Dielectric Response ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Fast Rotation

A study of the room-temperature ionic liquid N-methyl-N-ethylpyrrolidinium dicyanamide by dielectric relaxation spectroscopy over the frequency range 0.2 GHz ≤ ν ≤ 89 GHz has revealed that, in addition to the already known lower frequency processes, there is a broad featureless dielectric loss at higher frequencies. The latter is probably due to the translational (oscillatory) motions of the dipolar ions of the IL relative to each other, with additional contributions from their fast rotation.

Hypersonic Velocity, Absorption and Relaxation in Molten CSNO3

1977 ◽  
Vol 32 (1) ◽  
pp. 57-60 ◽  
Author(s):  
H. E. Gunilla Knape ◽  
Lena M. Torell
Keyword(s):  
Relaxation Time ◽  
High Frequency ◽  
Viscosity Coefficient ◽  
Sound Waves ◽  
Frequency Range ◽  
Ultrasonic Velocities ◽  
Hypersonic Velocity ◽  
Frequency Shifts ◽  
Bulk Viscosity Coefficient ◽  
Good Agreement

Abstract Brillouin spectra of molten CSNO3 were investigated for scattering angles between 40 and 140° and in a temperature interval of 420-520 °C. An Ar+ singlemode laser was used for excitation and the total instrumental width was ~265 MHz. The measured frequency shifts and linewidths of the Brillouin components were used to determine velocities and attenuations of thermal sound waves in the frequency range 2.3-7.0 GHz. A dispersion of 4-5% was found between the present hyper­ sonic velocities and reported ultrasonic velocities. A considerable decrease in attenuation with frequency was observed in the investigated frequency range, with the value at high frequency ap­ proaching the classical attenuation. The results are in good agreement with Mountain's theory of a single relaxation time. The relaxation time of the bulk viscosity coefficient was calculated to 1.2×10-10S.

Approaches to Predicting the Vertical Transmissibility of a Suspension Seat With a Seated Subject

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Jun Wu ◽  
Meihuan Wang ◽  
Yi Qiu
Keyword(s):  
High Frequency ◽  
Dynamic Stiffness ◽  
The Other ◽  
Human Model ◽  
Apparent Mass ◽  
Frequency Range ◽  
Air Suspension ◽  
In Series ◽  
Inert Mass ◽  
Good Agreement

Abstract In this paper, four methods were put forward to predict the transmissibility of an air suspension seat with a seated subject. For characterizing the dynamics of the suspension seat, two of the methods were based on developing a model of the air suspension seat and calibrating the parameters using the transmissibilities of the suspension and complete seat respectively with an inert mass from the experiment. The other two methods substituted the detailed modeling of the seat by two dynamic stiffness connecting in series calculated from two same transmissibilities measured in the experiment. For characterizing the biodynamics of the human body, two of the methods took advantage of the normalized apparent mass from published papers to take the place of the human model, while the other two methods made use of one measured seat transmissibility with a subject to deduce the apparent masses of all the subjects. Good agreement was illustrated between the experiment and model prediction for all the four methods. In addition, it also exhibited that a large discrepancy can be resulted in, especially in the high-frequency range, if the seat model was substituted by one integrated dynamic stiffness.

Electron effective-mass values in GaxIn1−xSb alloys

1969 ◽  
Vol 47 (6) ◽  
pp. 631-636 ◽  
Author(s):  
Marcel J. Aubin ◽  
Mathew B. Thomas ◽  
Eric H. van Tongerloo ◽  
John C. Woolley
Keyword(s):  
Effective Mass ◽  
High Frequency ◽  
Room Temperature ◽  
Composition Range ◽  
Bridgman Technique ◽  
Scattering Parameter ◽  
Electron Effective Mass ◽  
High Frequency Dielectric Constant ◽  
The Matrix ◽  
Good Agreement

Room-temperature measurements of Faraday rotation, magneto–thermoelectric power, and infrared reflectance have been made on homogeneous coarsely polycrystalline n-type samples of GaxIn1−xSb alloys produced by the horizontal Bridgman technique. Using these data and a Kane equation for the (000) conduction band, values of the bottom of the band effective mass m00* have been determined over the composition range 0 < x < 0.85, i.e. the range in which the subsidiary [Formula: see text] minima make no contribution. The results from the three different techniques show very good agreement. From the data, values are obtained also for the square of the matrix element P2, the high-frequency dielectric constant ε∞, and the scattering parameter s for the various alloy specimens.

High Performance Microvalve Array

2005 ◽  
Author(s):  
Dong Gun Lee ◽  
Daniel D. Shin ◽  
Gregory P. Carman
Keyword(s):  
Flow Rate ◽  
Wafer Bonding ◽  
High Frequency ◽  
High Performance ◽  
Silicon On Insulator ◽  
Experimental Result ◽  
Measured Flow ◽  
Flap Thickness ◽  
Large Flow ◽  
Good Agreement

The fabrication, analysis, and testing of a large flow rate and high frequency microvalve array are presented in this paper. The array consists of 88-microvalves fabricated on a silicon-on-insulator (SOI) substrate. The SOI wafer simplifies the fabrication process and eliminates the need for multi-layer surface micromachining process and bulk wafer-bonding procedures. The analytical resonant frequency of the valve is up to 50 kHz and operates at high delta pressures (i.e. 0.14 MPa). The microvalves are fabricated with various flap widths ranging from 300 to 400 μm and flap thickness ranging from 10 to 13 μm. The results indicate that flap displacement and flow rate are strongly dependent on flap thicknesses and to a lesser degree on flap widths increases. The resonance frequency with valve flap thickness increases and width decreases. Comparison between predicted and measured flow rate shows good agreement. A flow rate up to 35 cc/sec was measured. A failure criterion is also presented using the fracture stress analysis and shows good agreement with experimental result.

scholarly journals On the forbidden graphene’s ZO (out-of-plane optic) phononic band-analog vibrational modes in fullerenes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jesús N. Pedroza-Montero ◽  
Ignacio L. Garzón ◽  
Huziel E. Sauceda
Keyword(s):  
High Frequency ◽  
Density Functional ◽  
Room Temperature ◽  
Bulk Material ◽  
Characteristic Line ◽  
Vibrational Modes ◽  
Frequency Range ◽  
Functional Theory ◽  
Phonon Band ◽  
Out Of Plane

AbstractThe study of nanostructures’ vibrational properties is at the core of nanoscience research. They are known to represent a fingerprint of the system as well as to hint the underlying nature of chemical bonds. In this work, we focus on addressing how the vibrational density of states (VDOS) of the carbon fullerene family (Cn: n = 20 → 720 atoms) evolves from the molecular to the bulk material (graphene) behavior using density functional theory. We find that the fullerene’s VDOS smoothly converges to the graphene characteristic line-shape, with the only noticeable discrepancy in the frequency range of the out-of-plane optic (ZO) phonon band. From a comparison of both systems we obtain as main results that: (1) The pentagonal faces in the fullerenes impede the existence of the analog of the high frequency graphene’s ZO phonons, (2) which in the context of phonons could be interpreted as a compression (by 43%) of the ZO phonon band by decreasing its maximum allowed radial-optic vibration frequency. And 3) as a result, the deviation of fullerene’s VDOS relative to graphene may hold important thermodynamical implications, such as larger heat capacities compared to graphene at room-temperature. These results provide insights that can be extrapolated to other nanostructures containing pentagonal rings or pentagonal defects.

scholarly journals Comparison of the fast Lyman-Alpha and LICOR hygrometers for measuring airborne turbulent fluctuations

2017 ◽  
Author(s):  
Astrid Lampert ◽  
Jörg Hartmann ◽  
Falk Pätzold ◽  
Lennart Lobitz ◽  
Peter Hecker ◽  
...  
Keyword(s):  
High Frequency ◽  
Frequency Noise ◽  
Closed Path ◽  
Mixing Ratio ◽  
Frequency Range ◽  
Absolute Value ◽  
Lyman Alpha ◽  
Airborne Measurements ◽  
Open Path ◽  
Good Agreement

Abstract. The properties of fast hygrometers, the Lyman-Alpha and different LICOR humidity sensors, are analysed in direct intercomparison flights on different airborne platforms. One vibration isolated closed-path and two non-isolated open path LICOR sensors were installed on the twin engine turbo-prop aircraft Dornier 128. The closed-path sensor provided absolute values and fluctuations of the water vapour mixing ratio in good agreement with the Lyman-Alpha. The signals of the two open-path sensors showed considerable high frequency noise, and the absolute value of the mixing ratio was observed to drift with time in this vibrational environment. On the helicopter-towed sonde Helipod with very low vibration level the open-path LICOR sensor agreed very well with the Lyman-Alpha over the entire frequency range up to 3 Hz. The results show that the LICOR sensors are well suited for airborne measurements of humidity fluctuations, provided that a vibrationsless environment is given, and this turns out to be more important than close sensor spacing.

The Giant Dielectric Constant of Y2NiMnO6 Ceramics for DC Bias

2017 ◽  
Vol 866 ◽  
pp. 277-281
Author(s):  
Naphat Albutt ◽  
Suejit Pechprasarn ◽  
Pattaraporn Damkoengsuntorn ◽  
Thanapong Sareein
Keyword(s):  
Dielectric Constant ◽  
Dielectric Permittivity ◽  
Room Temperature ◽  
Frequency Range ◽  
Electronic Components ◽  
Giant Dielectric ◽  
High Dielectric Permittivity ◽  
Dc Bias ◽  
Giant Dielectric Constant ◽  
High Dielectric

In this work, the uses of giant dielectric constant of Y2NiMnO6 ceramics were investigated in the frequency range from 1 kHz to 3 MHz. The Y2NiMnO6 ceramics were sintered at 1400 °C for 6, 12, 18 and 24 hours, respectively. The dielectric properties of Y2NiMnO6 ceramics were examined in dc bias from 0 to 1.5 volt at room temperature. We found that all sintering times displayed high dielectric permittivity at frequencies below 105 Hz, above which the values decreased significantly, applied dc bias also reduced dielectric permittivity. The peak of dielectric loss decreased significantly at high dc bias due to decreased contribution of dc conductivity in grain ceramics. This research has characterised electrical properties of Y2NiMnO6 ceramics which maybe suitable for electronic components including batteries and capacitors.

The Range Distribution of Nd Ions Implanted in Silicon-on-Insulator

2011 ◽  
Vol 306-307 ◽  
pp. 315-318
Author(s):  
Yi Liang ◽  
Hong Zhen Li ◽  
Shuang Li ◽  
Feng Xiang Wang ◽  
Xi Feng Qin
Keyword(s):  
Monte Carlo ◽  
Room Temperature ◽  
Silicon On Insulator ◽  
Monte Carlo Code ◽  
Experiment Data ◽  
Lateral Deviation ◽  
Projected Range ◽  
The Mean ◽  
The Difference ◽  
Good Agreement

In view of the influence of the projected range, the range straggling, and the lateral deviation of ions in materials on the property of photoelectric integration devices fabricated by ion implantation, the mean projected ranges and range straggling for energetic 200 – 500 keV neodymium (Nd) ions implanted in silicon-on-insulator (SOI) at room temperature were measured by means of Rutherford backscattering followed by spectrum analysis.The measured results are compared with Monte Carlo code (SRIM2006) predictions. Our results show that the measured values of the mean projected rangeRpare good agreement with the SRIM calculated values; for the range straggling ΔRp, the difference between the experiment data and the calculated results is much higher than that ofRp.

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