scholarly journals Design and Research of Inductive Oil Pollutant Detection Sensor Based on High Gradient Magnetic Field Structure

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 638
Author(s):  
Wei Li ◽  
Chenzhao Bai ◽  
Chengjie Wang ◽  
Hongpeng Zhang ◽  
Lebile Ilerioluwa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Signal To Noise Ratio ◽  
Detection Accuracy ◽  
Iron Particles ◽  
Signal To Noise ◽  
Gradient Magnetic Field ◽  
High Gradient ◽  
Copper Particles ◽  
Pollutant Detection ◽  
Noise Ratio

An inductive oil pollutant detection sensor based on a high-gradient magnetic field structure is designed in this paper, which is mainly used for online detection and fault analysis of pollutants in hydraulic and lubricating oil systems. The innovation of the sensor is based on the inductance detection method. Permalloy is embedded in the sensing region of the sensor, so that the detection area generates a high gradient magnetic field to enhance the detection accuracy of the sensor. Compared with traditional inductive sensors, the sensor has a significant improvement in detection accuracy, and the addition of permalloy greatly improves the stability of the sensor’s detection unit structure. The article theoretically analyzes the working principle of the sensor, optimizes the design parameters and structure of the sensor through simulation, determines the best permalloy parameters, and establishes an experimental system for verification. Experimental results show that when a piece of permalloy is added to the sensing unit, the signal-to-noise ratio (SNR) of iron particles is increased by more than 20%, and the signal-to-noise ratio of copper particles is increased by more than 70%. When two pieces of permalloy are added, the signal-to-noise ratio for iron particles is increased by more than 70%, and the SNR for copper particles is increased several times. This method raises the lower limit of detection for ferromagnetic metal particles to 20 μm, and the lower limit for detection of non-ferromagnetic metal particles to 80 μm, which is the higher detection accuracy of the planar coil sensors. This paper provides a new and faster online method for pollutant detection in oil, which is of great significance for diagnosing and monitoring the health of oil in mechanical systems.

scholarly journals Signal-to-noise ratio, T2 , and T2* for hyperpolarized helium-3 MRI of the human lung at three magnetic field strengths

2016 ◽  
Vol 78 (4) ◽  
pp. 1458-1463 ◽  
Author(s):  
Peter Komlosi ◽  
Talissa A. Altes ◽  
Kun Qing ◽  
Karen E. Mooney ◽  
G. Wilson Miller ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Human Lung ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Hyperpolarized Helium ◽  
Helium 3 ◽  
Noise Ratio ◽  
Field Strengths

scholarly journals HEART BEAT DETECTION IN NOISY ECG SIGNALS USING STATISTICAL ANALYSIS OF THE AUTOMATICALLY DETECTED ANNOTATIONS / ŠIRDIES DŪŽIŲ NUSTATYMAS IŠ IŠKRAIPYTŲ EKG SIGNALŲ ATLIEKANT AUTOMATIŠKAI APTIKTŲ ATSKAITŲ STATISTINĘ ANALIZĘ

2015 ◽  
Vol 7 (3) ◽  
pp. 300-303
Author(s):  
Andrius Gudiškis
Keyword(s):  
Signal To Noise Ratio ◽  
Heart Beat ◽  
High Signal ◽  
Detection Accuracy ◽  
Ecg Signal ◽  
Signal To Noise ◽  
Ecg Signals ◽  
Arterial Blood ◽  
Boundary Estimation ◽  
Noise Ratio

This paper proposes an algorithm to reduce the noise distortion influence in heartbeat annotation detection in electrocardiogram (ECG) signals. Boundary estimation module is based on energy detector. Heartbeat detection is usually performed by QRS detectors that are able to find QRS regions in a ECG signal that are a direct representation of a heartbeat. However, QRS performs as intended only in cases where ECG signals have high signal to noise ratio, when there are more noticeable signal distortion detectors accuracy decreases. Proposed algorithm uses additional data, taken from arterial blood pressure signal which was recorded in parallel to ECG signal, and uses it to support the QRS detection process in distorted signal areas. Proposed algorithm performs as well as classical QRS detectors in cases where signal to noise ratio is high, compared to the heartbeat annotations provided by experts. In signals with considerably lower signal to noise ratio proposed algorithm improved the detection accuracy to up to 6%. Širdies ritmas yra vienas svarbiausių ir daugiausia informacijos apie pacientų būklę teikiančių fiziologinių parametrų. Širdies ritmas nustatomas iš elektrokardiogramos (EKG), atliekant QRS regionų, kurie yra interpretuojami kaip širdies dūžio ãtskaitos, paiešką. QRS regionų aptikimas yra klasikinis uždavinys, nagrinėjamas jau keletą dešimtmečių, todėl širdies dūžių nustatymo iš EKG signalų metodų yra labai daug. Deja, šie metodai tikslūs ir patikimi tik esant dideliam signalo ir triukšmo santykiui. Kai EKG signalai labai iškraipomi, QRS aptiktuvai ne visada gali atskirti QRS regioną, o kartais jį randa ten, kur iš tikro jo būti neturėtų. Straipsnyje siūlomas algoritmas, kurį taikant sumažinama triukšmo įtaka nustatant iš EKG signalų QRS regionus. Tam naudojamas QRS aptiktuvas, kartu prognozuojantis širdies dūžio atskaitą. Remiamasi arterinio kraujo spaudimo signalo duomenimis, renkama atskaitų statistika ir atliekama jos analizė.

scholarly journals A block-wise frame difference method for real-time video motion detection

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878363 ◽  
Author(s):  
Han Wei ◽  
Qiao Peng
Keyword(s):  
Real Time ◽  
Motion Detection ◽  
Difference Method ◽  
Moving Objects ◽  
Signal To Noise Ratio ◽  
Detection Accuracy ◽  
Signal To Noise ◽  
Time Motion ◽  
Frame Difference ◽  
Noise Ratio

This article proposes a motion detection method for real-time video analysis. It is the fundamental principle that the parts of the moving objects and the local changes of the images captured by static cameras are strongly correlated. Peak signal-to-noise ratio calculated in a block can characterize the significance of the changes in this area. Moving objects can therefore be detected by thresholding the peak signal-to-noise ratio of the blocks between two adjacent frames. The block-wise scheme used in this frame difference method can explore the local correlation of the movement in both space and time domains. This approach is robust to analyze the video images with noise and high variance caused by environmental changes, such as illuminations changes. Compared with other methods, the proposed method can achieve relatively high detection accuracy with less computation time, where real-time motion detection is available. Experimental results show that the proposed method cost averagely 50% of the running time of ViBe with 3.5% increase of the F-score on detection accuracy.

A triple-drain MOSFET magnetic-field sensor

1985 ◽  
Vol 63 (6) ◽  
pp. 695-698 ◽  
Author(s):  
A. Nathan ◽  
A. M. J. Huiser ◽  
H. P. Baltes ◽  
H. G. Schmidt-Weinmar
Keyword(s):  
Magnetic Field ◽  
Surface Charge ◽  
Signal To Noise Ratio ◽  
Magnetic Field Sensor ◽  
Two Dimensional ◽  
Signal To Noise ◽  
Linear Region ◽  
Field Sensor ◽  
Device Geometry ◽  
Noise Ratio

The two-dimensional distributions of the potential, current, and surface charge for a magnetic-field-sensitive N-channel MOSFET have been computed numerically. The MOSFET is operated in the linear region and is based on a triple-drain configuration. The sensitivity as well as the signal-to-noise ratio is studied for a variety of channel geometries, and an optimal device geometry is presented.

Two recent developments in XMCD

1998 ◽  
Vol 5 (3) ◽  
pp. 992-994 ◽  
Author(s):  
F. Baudelet ◽  
J. M. Dubuisson ◽  
C. Hébert ◽  
C. Créoff ◽  
L. Pointal ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Pressures ◽  
Magnetic Circular Dichroism ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Second Development ◽  
Superconducting Device ◽  
Fast Switching ◽  
Technical Developments ◽  
Noise Ratio

This paper reports on two new technical developments concerning sample environments for X-ray magnetic circular dichroism (XMCD). The first measurements under high pressures of up to 30 GPa are described. The difficulties of combining the techniques of high pressure and XMCD are commented on. The second development involves the use of a fast-switching magnetic field. A new superconducting device is used to perform XMCD measurements on paramagnetic compounds in magnetic fields of up to 6 T. The small amplitude of the XMCD signal imposes, for a given signal-to-noise ratio, a noise less than a few 10−5. The signal-to-noise ratio is improved by the use of a series of acquisitions, switching the magnetic field between each acquisition. A very fast switching mechanism has been built based on mechanical rotation of a superconducting coil, with the sample kept in place inside the coil. The XMCD signals at the L II,III-edges of paramagnetic rare-earth compounds have been measured at 4.5 K in fields of up to 6 T with a switching time of 11 s.

scholarly journals Inference of the chromospheric magnetic field configuration of solar plage using the Ca II 8542 Å line

2020 ◽  
Vol 644 ◽  
pp. A43 ◽  
Author(s):  
A. G. M. Pietrow ◽  
D. Kiselman ◽  
J. de la Cruz Rodríguez ◽  
C. J. Díaz Baso ◽  
A. Pastor Yabar ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Numerical Models ◽  
Signal To Noise Ratio ◽  
Field Configuration ◽  
Magnetic Field Configuration ◽  
Signal To Noise ◽  
Plage Region ◽  
Noise Ratio ◽  
The Magnetic Field

Context. It has so far proven impossible to reproduce all aspects of the solar plage chromosphere in quasi-realistic numerical models. The magnetic field configuration in the lower atmosphere is one of the few free parameters in such simulations. The literature only offers proxy-based estimates of the field strength, as it is difficult to obtain observational constraints in this region. Sufficiently sensitive spectro-polarimetric measurements require a high signal-to-noise ratio, spectral resolution, and cadence, which are at the limit of current capabilities. Aims. We use critically sampled spectro-polarimetric observations of the Ca II 8542 Å line obtained with the CRISP instrument of the Swedish 1-m Solar Telescope to study the strength and inclination of the chromospheric magnetic field of a plage region. This will provide direct physics-based estimates of these values, which could aid modelers to put constraints on plage models. Methods. We increased the signal-to-noise ratio of the data by applying several methods including deep learning and PCA. We estimated the noise level to be 1 × 10−3 Ic. We then used STiC, a non-local thermodynamic equilibrium inversion code to infer the atmospheric structure and magnetic field pixel by pixel. Results. We are able to infer the magnetic field strength and inclination for a plage region and for fibrils in the surrounding canopy. In the plage we report an absolute field strength of |B| = 440 ± 90 G, with an inclination of 10° ±16° with respect to the local vertical. This value for |B| is roughly double of what was reported previously, while the inclination matches previous studies done in the photosphere. In the fibrillar region we found |B| = 300 ± 50 G, with an inclination of 50° ±13°.

scholarly journals Interelement Decoupling Strategies at UHF MRI

2021 ◽  
Vol 9 ◽  
Author(s):  
Irena Zivkovic
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Field ◽  
Signal To Noise Ratio ◽  
Larmor Frequency ◽  
Resonance Imaging ◽  
Signal To Noise ◽  
Ultrahigh Field ◽  
Coil Arrays ◽  
Noise Ratio ◽  
Rf Signal

Moving to the ultrahigh field magnetic resonance imaging (UHF MRI) brought many benefits such as potentially higher signal-to-noise ratio, contrast-to-noise ratio, and improved spectral resolution. The UHF MRI regime also introduced some challenges which could prevent full exploitation of mentioned advantages. A higher static magnetic field means increase in Larmor frequency, which further implies the shorter wavelength in a tissue. The shorter wavelength causes interferences of the RF signal and inhomogeneous excitation, which can be partially resolved by the introduction of the multichannel coil arrays. The biggest problem in UHF multichannel densely populated arrays is the existence of the interelement coupling, which should be minimized as much as possible. This article presents the nonconventional, recently developed decoupling techniques used in UHF MRI.

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