scholarly journals Control of Néel-type Magnetic Kinks Confined in a Square Nanostructure by Spin-Polarized Currents

2021 ◽  
Vol 9 ◽  
Author(s):  
Ji-Pei Chen ◽  
Jia-Qiang Lin ◽  
Xiao Song ◽  
Yuan Chen ◽  
Zhi-Feng Chen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Topological Structure ◽  
Topological Properties ◽  
Micromagnetic Simulations ◽  
On Demand ◽  
Current Pulses ◽  
Spin Polarized ◽  
Degenerate States ◽  
The Individual ◽  
And Control

Magnetic skyrmion in chiral magnet exhibits a variety of unique topological properties associated with its innate topological structure. This inspires a number of ongoing searching for new topological magnetic textures. In this work, we used micromagnetic simulations and Monte Carlo simulations to investigate an exotic Néel-type magnetic kinks in square-shaped nanostructures of chiral magnets, which performs rather stably in the absence of magnetic field. The individual magnetic kink can reside in one of the four possible corners, and carry possibly upward or downward core polarity, constituting eight degenerate states. In addition, these kinks also exhibit unique behaviors of generation, stability and dynamics, as revealed by micromagnetic simulations. It was found that such kinks can be created, annihilated, displaced, and polarity-reversed on demand by applying a spin-polarized current pulse, and are easily switchable among the eight degenerate states. In particularly, the kinks can be switched toward the ferromagnetic-like states and backward reversibly by applying two successive current pulses, indicating the capability of writing and deleting the kink structures. These findings predict the existence of Néel-type magnetic kinks in the square-shaped nanostructures, as well as provide us a promising approach to tailor the kinks by utilizing the corners of the nanostructures, and control these states by spin-polarized currents. The present work also suggests a theoretical guide to explore other chiral magnetic textures in nanostructures of polygon geometries.

Design of a Magnetic Field-Based Multi Degree-of-Freedom Orientation Sensor Using the Distributed-Multiple-Pole Model

2007 ◽  
Author(s):  
Kok-Meng Lee ◽  
Hungsun Son
Keyword(s):  
Magnetic Field ◽  
Real Time ◽  
Rotating Shaft ◽  
Precision Control ◽  
Real Time Measurement ◽  
Angular Measurements ◽  
Orientation Sensor ◽  
The Individual ◽  
And Control ◽  
Spinning Shaft

Precision control of a tiltable spinning shaft requires real-time measurement of the inclination. Conventional single-axis encoders, though capable of providing high-resolution (linear or angular) measurements, rely on mechanical linkages (that often introduce frictions, backlashes, and singularities) to constrain the device so that the three-DOF motion can be deduced from the individual orthogonal measurements. Vision-based sensors, which have the attractive features of being non-contact, are limited to low speed measurements. We present here an efficient method for designing a magnetic field-based orientation sensor for devices where orientation control of a rotating shaft under the influence of a magnetic field is required. The ability to characterize the magnetic fields and forces in addition to orientation sensing can offer a number of advantages in real-time computation and control.

scholarly journals A Novel Design of a 3D Racetrack Memory Based on Functional Segments in Cylindrical Nanowire Arrays

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2403
Author(s):  
Javier Rial ◽  
Mariana P. Proenca
Keyword(s):  
Low Cost ◽  
Memory Device ◽  
Nanowire Arrays ◽  
High Yield ◽  
Magnetic Domains ◽  
Micromagnetic Simulations ◽  
Current Pulses ◽  
Spin Polarized ◽  
Innovative Idea ◽  
Vertically Aligned

A racetrack memory is a device where the information is stored as magnetic domains (bits) along a nanowire (track). To read and record the information, the bits are moved along the track by current pulses until they reach the reading/writing heads. In particular, 3D racetrack memory devices use arrays of vertically aligned wires (tracks), thus enhancing storage density. In this work, we propose a novel 3D racetrack memory configuration based on functional segments inside cylindrical nanowire arrays. The innovative idea is the integration of the writing element inside the racetrack itself, avoiding the need to implement external writing heads next to the track. The use of selective magnetic segments inside one nanowire allows the creation of writing and storage sections inside the same track, separated by chemical constraints identical to those separating the bits. Using micromagnetic simulations, our study reveals that if the writing section is composed of two segments with different coercivities, one can reverse its magnetization independently from the rest of the memory device by applying an external magnetic field. Spin-polarized current pulses then move the information bits along selected tracks, completing the writing process by pushing the new bit into the storage section of the wire. Finally, we have proven the efficacy of this system inside an array of 7 nanowires, opening the possibility to use this configuration in a 3D racetrack memory device composed of an array of thousands of nanowires produced by low-cost and high-yield template-electrodeposition methods.

scholarly journals Isolated skyrmion, skyrmion lattice and antiskyrmion lattice creation through magnetization reversal in Co/Pd nanostructure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sateesh Kandukuri ◽  
V. Satya Narayana Murthy ◽  
P. K. Thiruvikraman
Keyword(s):  
Current Density ◽  
Magnetization Reversal ◽  
Energy Efficient ◽  
Pulse Width ◽  
Density Current ◽  
Topological Properties ◽  
Magnetic Systems ◽  
Micromagnetic Simulations ◽  
Spin Polarized ◽  
Moriya Interaction

AbstractSkyrmion and antiskyrmion spin textures are axisymmetric inhomogeneous localized objects with distinct chirality in magnetic systems. These spin textures are potential candidates for the next generation energy-efficient spintronic applications due to their unique topological properties. Controlled and effective creation of the spin textures is required to use in conventional and neuromorphic computing applications. Here we show by micromagnetic simulations creating an isolated skyrmion, skyrmion lattice and antiskyrmion lattice through the magnetization reversal in Co/Pd multilayer nanostructure using spin-polarized current. The spin textures' stability depends on the spin-polarized current density, current pulse width, and Dzyaloshinskii–Moriya interaction (DMI). Antiskyrmions are evolved during the formation of a single skyrmion and skyrmion lattice. Skyrmion and antiskyrmion lattices together are observed for lower pulse width, 0.05 ns. Our micromagnetic studies suggest that the two distinct lattice phases' evolution could help to design the topological spin textures-based devices.

ABOUT UNIFORMITY OF THE PHENOMENOLOGY AND THE MATHEMATICAL DESCRIPTION OF SO-CALLED « JOINED» ACTION OF HAZARDS AND COMBINED TOXICITY (ON THE EXAMPLE OF A COMBIBATION OF THE FLUORIDE AND THE STATIC MAGNETIC FIELD)

2016 ◽  
pp. 13-20
Author(s):  
B. A. Katsnelson ◽  
M. P. Sutunkova ◽  
N. A. Tsepilov ◽  
V. G. Panov ◽  
A. N. Varaksin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Point Of View ◽  
Whole Body ◽  
Surface Model ◽  
Combined Toxicity ◽  
Fluoride Solution ◽  
Adverse Action ◽  
Biochemical Indices ◽  
And Control

Sodium fluoride solution was injected i.p. to three groups of rats at a dose equivalent to 0.1 LD50 three times a week up to 18 injections. Two out of these groups and two out of three groups were sham-injected with normal saline and were exposed to the whole body impact of a 25 mT static magnetic field (SMF) for 2 or 4 hr a day, 5 times a week. Following the exposure, various functional and biochemical indices were evaluated along with histological examination and morphometric measurements of the femur in the differently exposed and control rats. The mathematical analysis of the combined effects of the SMF and fluoride based on the a response surface model demonstrated that, in full correspondence with what we had previously found for the combined toxicity of different chemicals, the combined adverse action of a chemical plus a physical agent was characterized by a tipological diversity depending not only on particular effects these types were assessed for but on the dose and effect levels as well. From this point of view, the indices for which at least one statistically significant effect was observed could be classified as identifying (I) mainly single-factor action; (II) additive unidirectional action; (III) synergism (superadditive unidirectional action); (IV) antagonism, including both subadditive unidirectional action and all variants of contradirectional action.

scholarly journals Interactive effects between travel behaviour and COVID-19: a questionnaire study

2021 ◽  
Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee
Keyword(s):  
Early Stage ◽  
Travel Behaviour ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Individual Level ◽  
Passenger Volume ◽  
Spatial Autoregressive ◽  
Railway Passenger ◽  
The Individual ◽  
And Control

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.

scholarly journals Medicolegal Causation Investigation of Bacterial Endocarditis Associated with an Oral Surgery Practice Using the INFERENCE Approach

2021 ◽  
Vol 18 (14) ◽  
pp. 7530
Author(s):  
Putri Dianita Ika Meilia ◽  
Maurice P. Zeegers ◽  
Herkutanto ◽  
Michael D. Freeman
Keyword(s):  
Oral Surgery ◽  
Invasive Procedure ◽  
Bacterial Endocarditis ◽  
Infection Prevention And Control ◽  
Healthcare Associated Infection ◽  
Department Of Health ◽  
The Individual ◽  
Healthcare Associated ◽  
And Control ◽  
Causation Analysis

Investigating causation is a primary goal in forensic/legal medicine, aiming to establish the connection between an unlawful/negligent act and an adverse outcome. In malpractice litigation involving a healthcare-associated infection due to a failure of infection prevention and control practices, the medicolegal causal analysis needs to quantify the individual causal probabilities to meet the evidentiary requirements of the court. In this paper, we present the investigation of the most probable cause of bacterial endocarditis in a patient who underwent an invasive procedure at a dental/oral surgical practice where an outbreak of bacterial endocarditis had already been identified by the state Department of Health. We assessed the probability that the patient’s endocarditis was part of the outbreak versus that it was an unrelated sporadic infection using the INFERENCE (Integration of Forensic Epidemiology and the Rigorous Evaluation of Causation Elements) approach to medicolegal causation analysis. This paper describes the step-by-step application of the INFERENCE approach to demonstrate its utility in quantifying the probability of causation. The use of INFERENCE provides the court with an evidence-based, transparent, and reliable guide to determine liability, causation, and damages.

P6547The energy cost of His bundle pacing can be curtailed

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
F Zanon ◽  
L Marcantoni ◽  
G Pastore ◽  
E Baracca ◽  
C Picariello ◽  
...  
Keyword(s):  
Pulse Duration ◽  
Safety Margin ◽  
Significant Saving ◽  
His Bundle ◽  
His Bundle Pacing ◽  
On Demand ◽  
Mild Reduction ◽  
Ventricular Activation ◽  
The Individual ◽  
Current Drain

Abstract Introduction His bundle pacing (HBP) allows physiological ventricular activation and prevents the electrical and mechanical desynchronization generally induced by myocardial stimulation, which can increase the risk of atrial fibrillation and heart failure. On the other hand, reliable HBP capture often requires higher energy than conventional myocardial pacing. This reduces the expected life of the stimulator and might limit the diffusion of HBP in the clinical practice. Purpose Decreasing HBP current drain by careful management of stimulation safety margin and pulse duration. Methods In 28 patients undergoing DDD pacing with HBP, a third lead was implanted in RV apex to provide back-up pacing on demand. HBP and apical leads were connected, respectively, to the V1 and V2 channels of a 3-chamber stimulator. When HBP was effective, apical sensing occurred within the VV delay and prevented V2 stimulation. In contrast, in case of HBP failure, V2 sensing was missing and apical back-up pacing was promptly delivered at the end of the VV delay. The availability of a back-up pulse on demand allowed reducing the HBP safety margin with no risk. Furthermore, the individual HBP strength-duration curve was derived in the aim of optimizing the Hisian pulse parameters, which are the major determinants of the device current drain. Results Correct back-up inhibition by successful HBP and stimulation in the event of capture loss was achieved in all the patients. The latency from Hisian pacing to apical sensing averaged 96±14 ms. According to the pacemaker counters, no back-up pulse was delivered in daily life in 59% of patients. In the remaining, the prevalence of back-up stimulation never exceeded 15% of paced ventricular cycles. The high HBP threshold was essentially due to an increased rheobase (1.2±0.6 V), while the chronaxie ranged from 0.30 to 0.53 ms in 71% of patients (median 0.44 ms), exceeding 0.6 ms only in 29% of the cases. An average current saving of 5.4±3.0 μA was obtained at the expense of a mild reduction in HBP safety margin (from 1.6±0.2 to 1.4±0.1 times). HBP and apical back-up Conclusions Back-up stimulation on demand is a reliable option to decrease HBP current drain and prolong the stimulator service life with full safety. In most of the cases, significant saving can be achieved by pulse shortening, as the chronaxie time is in the same range as with myocardial stimulation and longer pulses are not required. A pulse duration exceeding 0.6 ms is indicated in less than 1/3 of the implants.

Anti-craving biofeedback program in clinical course of pathological addictions

2017 ◽  
Vol 41 (S1) ◽  
pp. s879-s879
Author(s):  
I. Sosin ◽  
Y. Chuev ◽  
A. Volkov ◽  
O. Goncharova
Keyword(s):  
Individual Preference ◽  
Emotional States ◽  
Digital Information ◽  
External Monitoring ◽  
Computer Testing ◽  
Mode Of Life ◽  
Competing Interest ◽  
The Individual ◽  
Monitoring Module ◽  
And Control

IntroductionModern clinical narcology searches for anti-craving programs to overcome psychoactive substances (PAS) pathological addiction with bio-adaptive regulation of systems (BARS).Aims and objectivesTo develop computer modified biofeedback program integrated with Luscher test.MethodTwenty-two PAS addicts who were undergoing biofeedback modified psycho-training were examined. Computer rheoencephalogram (REG) was used as an external monitoring module.ResultsTechnologically novel biofeedback computer modification was developed with preceding Luscher computer testing for determination of the individual preference colour and the colour producing individual unpleasant associations in respondents. Consequently, biofeedback program was corrected differentially by changing standard colour templates for those personified on monitor. Cerebral hemodynamics condition transferred to individually designed for a particular respondent colour registers is used as a homeostatic parameter reflecting alcohol craving presence/absence: in case of the disordered REG parameters the signal reflects the respondent's unpleasant (negative) colour, and with no craving the screen is filled with positive, pleasant, favourite colour. During BARS auto-training the respondents’ skills to mediate present subjective clinical PAS craving manifestations with unpleasant colour and the experimental auto-training method have been mastered, and those psycho emotional states which displace PAS craving symbolic colour from the screen are selected, and it is substituted with favourite colour (symbol of healthy mode of life motivations).ConclusionsUsage of combined BARS biofeedback improved effectiveness of the training and allowed to objectivize and control the condition of the patient getting reliable visual and digital information about either regress or activation of PAS craving and potential relapse of addictive behaviour.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Magnetic Confinement and Control of Trajectories of Discharge Species in Atmospheric-Pressure Analytical Spark Discharges

1987 ◽  
Vol 41 (2) ◽  
pp. 200-207 ◽  
Author(s):  
Vahid Majidi ◽  
David M. Coleman
Keyword(s):  
Magnetic Field ◽  
Atmospheric Pressure ◽  
Magnetic Confinement ◽  
Post Discharge ◽  
Conducting Channel ◽  
Filamentary Structure ◽  
Spark Discharges ◽  
Time Space ◽  
Series Of Experiments ◽  
And Control

A series of experiments, designed to help characterize the behavior of an analytical spark discharge in an external pulsed magnetic field, is described. Results include controlled formation and deformation of a spark's post-discharge torus utilizing different magnetic field configurations. One manifestation of this research was discovery of a new filamentary structure which extends from the spark conducting channel to the magnet pole face(s). These features were investigated via their refracted light (Schlieren) and spectroscopic (time/space/wavelength-resolved) properties. Practical ramifications of this control are discussed.

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