The Effect of Magnetic Field on Magnetotactic Bacteria Behaviors

2008 ◽  
Vol 57 ◽  
pp. 61-66
Author(s):  
Hideharu Takahashi ◽  
Hiroshige Kikura ◽  
Tat Suo Iwasa ◽  
Shingo Watanabe ◽  
Masanori Aritomi
Keyword(s):  
Magnetic Field ◽  
Magnetotactic Bacteria ◽  
Behavior Control ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Video Cameras ◽  
Image Processing Techniques ◽  
Darkfield Microscopy ◽  
Processing Techniques ◽  
Observation Results

The motion of magnetotactic bacteria was observed using an optical darkfield microscopy. The images were taken using video cameras, and measured by image processing techniques. In our experiment, it was found that the bacteria motion was found to follow to magnetic field frequency within some range. The observation results indicate the possibility of the bacteria behavior control by magnetic field.

Controllability of a Magnetorheological Fluid Squeeze Film Damper under Sinusoidal Magnetic Field

2007 ◽  
Vol 334-335 ◽  
pp. 1089-1092 ◽  
Author(s):  
Chang Sheng Zhu
Keyword(s):  
Magnetic Field ◽  
Squeeze Film ◽  
Field Frequency ◽  
Mr Fluid ◽  
Magnetic Field Frequency ◽  
Squeeze Film Damper ◽  
Fluid Damper ◽  
Sinusoidal Magnetic Field ◽  
Mr Fluid Damper ◽  
The Magnetic Field

The controllability of a magnetorheological(MR) fluid squeeze film damper under a sinusoidal magnetic field was experimentally studied on a flexible rotor. It is shown that the frequency of the excitation magnetic field has a great effect on the controllability of the MR fluid damper. As the magnetic field frequency increases, the controllability of the MR fluid damper significantly reduces. There is a maximum frequency of the magnetic field for a given magnetic field strength or a minimum strength of the magnetic field for a given magnetic field frequency to make the dynamic behavior of the MR damper be controllable. When the magnetic field frequency is over the maximum one or the magnetic field strength is less than the minimum one, the controllability of the MR fluid damper almost completely disappears and the dynamic behavior of the MR fluid damper with the sinusoidal magnetic field is the same as that without the magnetic field.

A depth camera based approach for automatic control of video cameras in lecture halls

2014 ◽  
Vol 11 (3) ◽  
pp. 169-183
Author(s):  
Michael Winkler ◽  
Kai Michael Höver ◽  
Max Mühlhäuser
Keyword(s):  
Design Methodology ◽  
Depth Information ◽  
Skeleton Model ◽  
Content Type ◽  
Camera Control ◽  
Video Cameras ◽  
Image Processing Techniques ◽  
Processing Techniques ◽  
Future Work ◽  
Networking Architecture

Purpose – The purpose of this study is to present a depth information-based solution for automatic camera control, depending on the presenter’s moving positions. Talks, presentations and lectures are often captured on video to give a broad audience the possibility to (re-)access the content. As presenters are often moving around during a talk, it is necessary to steer recording cameras. Design/methodology/approach – We use depth information from Kinect to implement a prototypical application to automatically steer multiple cameras for recording a talk. Findings – We present our experiences with the system during actual lectures at a university. We found out that Kinect is applicable for tracking a presenter during a talk robustly. Nevertheless, our prototypical solution reveals potential for improvements, which we discuss in our future work section. Originality/value – Tracking a presenter is based on a skeleton model extracted from depth information instead of using two-dimensional (2D) motion- or brightness-based image processing techniques. The solution uses a scalable networking architecture based on publish/subscribe messaging for controlling multiple video cameras.

scholarly journals Hall-Effect Sensor Technique for No Induced Voltage in AC Magnetic Field Measurements Without Current Spinning

2021 ◽  
Author(s):  
Anand Lalwani ◽  
Ananth Saran Yalamarthy ◽  
Debbie Senesky ◽  
Maximillian Holliday ◽  
Hannah Alpert
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Hall Effect ◽  
Induced Voltage ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Ac Magnetic Field ◽  
Hall Effect Sensor ◽  
Offset Voltage ◽  
The Magnetic Field

Accurately sensing AC magnetic field signatures poses a series of challenges to commonly used Hall-effect sensors. In particular, induced voltage and lack of high-frequency spinning methods are bottlenecks in the measurement of AC magnetic fields. We describe a magnetic field measurement technique that can be implemented in two ways: 1) the current driving the Hall-effect sensor is oscillating at the same frequency as the magnetic field, and the signal is measured at the second harmonic of the magnetic field frequency, and 2) the frequency of the driving current is preset, and the measured frequency is the magnetic field frequency plus the frequency of the current. This method has potential advantages over traditional means of measuring AC magnetic fields used in power systems (e.g., motors, inverters), as it can reduce the components needed (subsequently reducing the overall cost and size) and is not frequency bandwidth limited by current spinning. The sensing technique produces no induced voltage and results in a low offset, thus preserving accuracy and precision in measurements. Experimentally, we have shown offset voltage values between 8 and 27 μT at frequencies ranging from 100 Hz to 1 kHz, validating the potential of this technique in both cases

scholarly journals Hall-Effect Sensor Technique for No Induced Voltage in AC Magnetic Field Measurements Without Current Spinning

2021 ◽  
Author(s):  
Anand Lalwani ◽  
Ananth Saran Yalamarthy ◽  
Debbie Senesky ◽  
Maximillian Holliday ◽  
Hannah Alpert
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Hall Effect ◽  
Induced Voltage ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Ac Magnetic Field ◽  
Hall Effect Sensor ◽  
Offset Voltage ◽  
The Magnetic Field

Accurately sensing AC magnetic field signatures poses a series of challenges to commonly used Hall-effect sensors. In particular, induced voltage and lack of high-frequency spinning methods are bottlenecks in the measurement of AC magnetic fields. We describe a magnetic field measurement technique that can be implemented in two ways: 1) the current driving the Hall-effect sensor is oscillating at the same frequency as the magnetic field, and the signal is measured at the second harmonic of the magnetic field frequency, and 2) the frequency of the driving current is preset, and the measured frequency is the magnetic field frequency plus the frequency of the current. This method has potential advantages over traditional means of measuring AC magnetic fields used in power systems (e.g., motors, inverters), as it can reduce the components needed (subsequently reducing the overall cost and size) and is not frequency bandwidth limited by current spinning. The sensing technique produces no induced voltage and results in a low offset, thus preserving accuracy and precision in measurements. Experimentally, we have shown offset voltage values between 8 and 27 μT at frequencies ranging from 100 Hz to 1 kHz, validating the potential of this technique in both cases

Remagnetization Core Losses In The Massive Amorphous FeCoYb Alloy

2017 ◽  
Vol 68 (4) ◽  
pp. 698-700
Author(s):  
Katarzyna Bloch ◽  
Marcin Nabialek ◽  
Konrad Gruszka
Keyword(s):  
Magnetic Field ◽  
Amorphous Alloy ◽  
Power Loss ◽  
Eddy Currents ◽  
Magnetic Hysteresis ◽  
Bulk Amorphous Alloy ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Core Losses ◽  
Additional Losses

In this paper were studied the influence of magnetic field frequency and induction on the total core power loss � which is divided into eddy current loss, hysteresis loss and anomally losses of the bulk amorphous alloy. The total core power loss of the investigated bulk amorphous alloy increases with magnetic field frequency and peak induction. It follows a power relation similar to what has been observed in classical ribbons. In the investigated alloy in addition to losses due to magnetic hysteresis and eddy currents, other additional losses are present. However additional losses, emerging simultaneously to the component associated with migration relaxations are very weakly dependent on the frequency and temperature.

Influence of the ac magnetic field frequency on the magnetoimpedance of amorphous wire

2006 ◽  
Vol 39 (9) ◽  
pp. 1718-1723 ◽  
Author(s):  
A P Chen ◽  
C García ◽  
A Zhukov ◽  
L Domínguez ◽  
J M Blanco ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Amorphous Wire ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Ac Magnetic Field

Effect of magnetic field frequency on the shape of GMAW welding arc and weld microstructure properties

2019 ◽  
Vol 6 (8) ◽  
pp. 0865e5 ◽  
Author(s):  
Zi Qi Guan ◽  
Hong Xu Zhang ◽  
Xiao Guang Liu ◽  
Alexandr Babkin ◽  
Yun Long Chang
Keyword(s):  
Magnetic Field ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Weld Microstructure ◽  
Welding Arc ◽  
Gmaw Welding

RESONANT MAGNETOELECTRIC EFFECTS IN Ni/Pb(Zr,Ti)O3/FeCo TRILAYERED SEMICIRCULAR COMPOSITES

2013 ◽  
Vol 20 (01) ◽  
pp. 1350004 ◽  
Author(s):  
H. HONG ◽  
Y. G. WANG ◽  
K. BI ◽  
F. G. CHEN
Keyword(s):  
Magnetic Field ◽  
Field Frequency ◽  
Zero Bias ◽  
Resonant Frequencies ◽  
Magnetoelectric Effects ◽  
Magnetic Field Frequency ◽  
Voltage Coefficient ◽  
The Magnetic Field ◽  
Effective Excitation ◽  
Multifunctional Devices

Magnetoelectric (ME) effect has been studied in semicircular composites with a negative magnetostrictive/piezoelectric/positive magnetostrictive Ni/Pb(Zr,Ti)O3/FeCo trilayered structure. The ME behavior of the Ni/Pb(Zr,Ti)O3/FeCo is different from those in previous studies and zero-bias ME effects and four remarkable resonant peaks have been observed in the dependence of the ME voltage coefficient on the magnetic field frequency in the 1–150 kHz range. The effective excitation of the acoustical oscillations provided by the positive and negative magnetostrictive layers is responsible for the multifrequency ME effects. The results open up a suitable way to make multifunctional devices with multi-resonant-frequencies and/or zero-bias operations.

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