scholarly journals Exceeding natural resonance frequency limit of monodisperse Fe3O4 nanoparticles via superparamagnetic relaxation

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Ning-Ning Song ◽  
Hai-Tao Yang ◽  
Hao-Liang Liu ◽  
Xiao Ren ◽  
Hao-Feng Ding ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Fe3o4 Nanoparticles ◽  
Frequency Limit ◽  
Superparamagnetic Relaxation ◽  
Natural Resonance ◽  
Natural Resonance Frequency

A Review of Recent Developments in Atomic Force Microscopy Systems With Application to Manufacturing and Biological Processes

2003 ◽  
Author(s):  
Karthik Laxminarayana ◽  
Nader Jalili
Keyword(s):  
Resonance Frequency ◽  
Intermolecular Forces ◽  
Minimal Amount ◽  
Contact Mode ◽  
Tapping Mode ◽  
Atomic Force ◽  
Natural Resonance ◽  
Target Sample ◽  
Recent Developments ◽  
Natural Resonance Frequency

The atomic force microscope (AFM) system has evolved into a useful tool for direct measurements of microstructural parameters and intermolecular forces at nanoscale level with atomic-resolution characterization. Typically, these microcantilever systems are operated in three open-loop modes; non-contact mode, contact mode, and tapping mode. In order to probe electric, magnetic, and/or atomic forces of a selected sample, the non-contact mode is utilized by moving the cantilever slightly away from the sample surface and oscillating the cantilever at or near its natural resonance frequency. Alternatively, the contact mode acquires sample attributes by monitoring interaction forces while the cantilever tip remains in contact with the target sample. The tapping mode of operation combines qualities of both the contact and non-contact modes by gleaning sample data and oscillating the cantilever tip at or near its natural resonance frequency while allowing the cantilever tip to impact the target sample for a minimal amount of time. Recent research on AFM systems has focused on many fabrication and manufacturing processes at molecular levels due to its tremendous surface microscopic capabilities. This paper provides a review of such recent developments in AFM imaging systems with emphasis on operational modes, microcantilever dynamic modeling and control. Due to the important contributions of AFM systems to manufacturing, this paper also provides a comprehensive review of recent applications of different AFM systems in these important areas.

Spin sprayed Ni(–Zn)–Co ferrite films with natural resonance frequency exceeding 3GHz

2007 ◽  
Vol 101 (9) ◽  
pp. 09M502 ◽  
Author(s):  
Koichi Kondo ◽  
Shigeyoshi Yoshida ◽  
Hiroshi Ono ◽  
Masanori Abe
Keyword(s):  
Resonance Frequency ◽  
Natural Resonance ◽  
Ferrite Films ◽  
Natural Resonance Frequency

High-frequency electromagnetic properties of soft magnetic Nd2Co17 micron flakes fractured along c crystal plane with natural resonance frequency exceeding 10 GHz

2016 ◽  
Vol 108 (9) ◽  
pp. 092406 ◽  
Author(s):  
Yongbo Zhang ◽  
Peng Wang ◽  
Tianyong Ma ◽  
Ying Wang ◽  
Liang Qiao ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
High Frequency ◽  
Crystal Plane ◽  
Electromagnetic Properties ◽  
Soft Magnetic ◽  
Natural Resonance ◽  
Natural Resonance Frequency

Study of the Acoustic Oscillations of Flow Over Cavities: Part 2 — Sound Reduction

2002 ◽  
Author(s):  
Pascal He´mon ◽  
Xavier Amandole`se ◽  
Franc¸oise Santi ◽  
Jan Wojciechowski
Keyword(s):  
Resonance Frequency ◽  
Helmholtz Resonator ◽  
Sound Level ◽  
Broadband Noise ◽  
Two Dimensional ◽  
Acoustic Oscillations ◽  
Deep Cavity ◽  
Natural Resonance ◽  
Sound Reduction ◽  
Natural Resonance Frequency

We present experimental results obtained with a deep cavity, like an Helmholtz resonator, excited by an airflow. The resonance under the action of the vortices generated in the shear layer is well described and quantified. The mounting of actuators, based on a few piezo-electric elements, allows to generate a series of two-dimensional vortices forced at a frequency which is different than the natural resonance frequency. The sound level in the cavity is strongly decreased and the broadband noise of the turbulence only remains.

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