scholarly journals Cardiovascular System Interactions With The Local Earth Magnetic Field Fluctuations: A Cohort Study

2021 ◽  
Author(s):  
Greta Ziubryte ◽  
Gediminas Jarusevicius ◽  
Mantas Landauskas ◽  
Minvydas Ragulskis ◽  
Rollin McCraty ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cardiovascular System ◽  
High Frequency ◽  
Low Frequency ◽  
Local Magnetic Field ◽  
Coronary Syndrome ◽  
Increased Risk ◽  
Earth Magnetic Field ◽  
Field Activity ◽  
Human Cardiovascular System

Abstract Background: Geomagnetic storms strongly affect the human cardiovascular system, misbalancing adaptive mechanisms and causing severe adaptive stress responses at all levels of body regulation. Most physiological changes occur after a defined period following geomagnetic climate alterations, this ‘delay period’ lasts for 2-3 days. Methods: In total, 4730 patients admitted between 2015 and 2017 due to acute coronary syndrome (ACS) and acute onset of arrhythmias have been included into the study.Results: Higher time varying magnetic field (TVMF) activity in low frequency ranges is associated with lower number of admissions due to ACS, while higher TVMF activity in high frequency ranges is associated with increased risk for ACS occurrence. The greater TVMF activity in low frequency ranges is associated with higher rates of admission due to cardiac arrhythmias. Additional ACS analysis showed that red blood cell count decreases with increased MF strength in low frequency ranges, while white blood cells and platelets count increases in the same MF frequency ranges. The highest serum osteocalcin level was found 3 days after certain MF strength changes in low frequency ranges in patients with ACS. Strong correlations were found between more than 2 cases of AMI per day and MF strength changes 2- and 3- days before admission. Conclusions: Earth’s local magnetic field is strongly related on human cardiovascular system metabolism and neural regulation. Increased Magnetic field activity in low frequency ranges is associated with heart metabolism and may induce better cardiovascular health, while increased magnetic field activity in high frequency ranges leads to heart problems especially to occurrence of ischemic heart disease and arterial hypertension.

scholarly journals ANALYSIS OF HIGH-FREQUENCY C-CORE MAGNETIC FLUX LEAKAGES FOR BONE TUMOR WITH INDUCTION HEATING BY USING MULTI-COIL

2019 ◽  
Author(s):  
Metharak Jokpudsa ◽  
Supawat Kotchapradit ◽  
Chanchai Thongsopa ◽  
Thanaset Thosdeekoraphat
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Tumor Tissue ◽  
Low Frequency ◽  
Heat Energy ◽  
High Frequencies ◽  
Frequency Magnetic Field ◽  
High Frequency Magnetic Field ◽  
The Magnetic Field ◽  
Flux Leakage

High-frequency magnetic field has been developed pervasively. The induction of heat from the magnetic field can help to treat tumor tissue to a certain extent. Normally, treatment by the low-frequency magnetic field needed to be combined with magnetic substances. To assist in the induction of magnetic fields and reduce flux leakage. However, there are studies that have found that high frequencies can cause heat to tumor tissue. In this paper present, a new magnetic application will focus on the analysis of the high-frequency magnetic nickel core with multi-coil. In order to focus the heat energy using a high-frequency magnetic field into the tumor tissue. The magnetic coil was excited by 915 MHz signal and the combination of tissues used are muscle, bone, and tumor. The magnetic power on the heating predicted by the analytical model, the power loss density (2.98e-6 w/m3) was analyzed using the CST microwave studio.

scholarly journals Solitary potential structures observed in the magnetosheath by the Cluster spacecraft

2003 ◽  
Vol 10 (1/2) ◽  
pp. 3-11 ◽  
Author(s):  
J. S. Pickett ◽  
J. D. Menietti ◽  
D. A. Gurnett ◽  
B. Tsurutani ◽  
P. M. Kintner ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Time Series Data ◽  
Broad Band ◽  
Low Frequency ◽  
Bow Shock ◽  
Local Magnetic Field ◽  
Series Data ◽  
The Individual ◽  
Almost All ◽  
The Magnetic Field

Abstract. Bipolar pulses of ~ 25-100 µs in duration have been observed in the wave electric field data obtained by the Wideband plasma wave instrument on the Cluster spacecraft in the dayside magnetosheath. These pulses are similar in almost all respects to those observed on several spacecraft over the last few years. They represent solitary potential structures, and in this case, electron phase space holes. When the time series data containing the bipolar pulses on Cluster are transformed to the frequency domain by a windowed FFT, the pulses appear as typical broad-band features, extending from the low-frequency cutoff of the bandpass filter, ~ 1 kHz, up to as great as 20-40 kHz in some cases, with decreasing intensity as the frequency increases. The upper frequency cutoff of the broad band is an indication of the individual pulse durations (1/f). The solitary potential structures are detected when the local magnetic field is contained primarily in the spin plane, indicating that they propagate along the magnetic field. Their frequency extent and intensity seem to increase as the angle between the directions of the magnetic field and the plasma flow decreases from 90°. Of major significance is the finding that the overall profile of the broad-band features observed simultaneously by two Cluster spacecraft, separated by a distance of over 750 km, are strikingly similar in terms of onset times, frequency extent, intensity, and termination. This implies that the generation region of the solitary potential structures observed in the magnetosheath near the bow shock is very large and may be located at or near the bow shock, or be connected with the bow shock in some way.

Synchronization of low-frequency oscillations in the human cardiovascular system

2009 ◽  
Vol 19 (3) ◽  
pp. 033112 ◽  
Author(s):  
A. S. Karavaev ◽  
M. D. Prokhorov ◽  
V. I. Ponomarenko ◽  
A. R. Kiselev ◽  
V. I. Gridnev ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Low Frequency ◽  
Low Frequency Oscillations ◽  
Human Cardiovascular System

A parametric study of the vertical electric source

Geophysics ◽  
1995 ◽  
Vol 60 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Louise Pellerin ◽  
Gerald W. Hohmann
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Host Response ◽  
Low Frequency ◽  
Signal Strength ◽  
Phase Response ◽  
Vertical Magnetic Field ◽  
Electric Source ◽  
Measured Response ◽  
Quadrature Response

Measurement of the vertical magnetic field caused by a vertical electric source (VES) is an attractive exploration option because the measured response is caused by only 2-D and 3-D structures. The absence of a host response markedly increases the detectability of confined structures. In addition, the VES configuration offers advantages such as alleviating masking resulting from conductive overburden and the option of having a source functioning in a collapsed borehole. Applications of the VES, as in mineral exploration, seafloor exploration, and process monitoring such as enhanced oil recovery, are varied, but we limit this study to a classic mining problem—the location of a confined, conductive target at depth in the vicinity of a borehole. By analyzing the electromagnetic responses of a thin, vertical prism, a horizontal slab and an equidimensional body, we investigate the resolving capabilities, identify survey design problems, and provide interpretational insight for vertical magnetic field responses arising from a VES. Data acquisition problems, such as electrode contact within a borehole, are not addressed. Current channeling is the dominant mechanism by which a 2-D or 3-D target is excited. The response caused by currents induced in the target is relatively unimportant compared to that of channeled currents. At low frequencies, the in‐phase response results from galvanic currents from the source electrodes channeled through the target. The quadrature response, at all frequencies, results from currents induced in the host and channeled through the target. At high frequencies, in‐phase currents are also induced in the host and channeled through the target. Hence, the quadrature response and the high‐frequency in‐phase response are quite sensitive to the host resistivity. Time‐domain magnetic field responses show the same behavior as the quadrature component. Interpretation of low‐frequency vertical magnetic field measurements is straightforward for a source placed along strike of the target and a profile line traversing the target. The target is located under a sign reversal or null in the field for a flat‐lying or vertical target. A dipping target has an asymmetrical response, with reduced amplitude on the downdip lobe. The target is located between the maximum lobe and the null. Although the vertical magnetic field caused by a VES for a 2-D or 3-D structure is purely anomalous, the host layering can affect signal strength by more than an order of magnitude. A general knowledge of the location of the target and host layering is helpful in maximizing signal strength. In practice boreholes are not vertical. An angled source can introduce a response because of the horizontal component that can overwhelm the VES response. For low‐frequency, in‐phase, or magnetometric resistivity (MMR) measurements made with a source angled at less than 30 degrees from the vertical, the host response caused by a horizontal electric source (HES) is negligible, and the free space response is easily computed and removed from the total response leaving a response that can be interpreted as that being caused by a VES. The high‐frequency, in‐phase response and the quadrature response at any frequency caused by a HES are strongly dependent on the host resistivity and dominate the scattered response. The measured response, therefore, must be interpreted using sophisticated techniques that take source geometry and host resistivity into account.

Filamentation and collapse of Langmuir waves in a weak magnetic field

1982 ◽  
Vol 28 (1) ◽  
pp. 19-36 ◽  
Author(s):  
P. Rolland ◽  
S. G. Tagare
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Small Angle ◽  
Nonlinear Interaction ◽  
High Frequency ◽  
Weak Magnetic Field ◽  
Low Frequency ◽  
Langmuir Waves ◽  
The Magnetic Field

The filamentation and collapse of Langmuir waves in a weak magnetic field are analysed in two particular cases of low-frequency acoustic perturbations: (i) adiabatic perturbations which correspond to subsonic collapse, and (ii) nonadiabatic perturbations which correspond to supersonic collapse. Here the existence of Langmuir filaments and Langmuir collapse in a weak magnetic field are due to nonlinear interaction of high-frequency Langmuir waves (which make small angle with the external magnetic field) with low-frequency acoustic perturbations along the magnetic field.

scholarly journals Impact of TBI, PTSD, and Hearing Loss on Tinnitus Progression in a US Marine Cohort

2019 ◽  
Vol 184 (11-12) ◽  
pp. 839-846 ◽  
Author(s):  
Royce E Clifford ◽  
Dewleen Baker ◽  
Victoria B Risbrough ◽  
Mingxiong Huang ◽  
Kate A Yurgil
Keyword(s):  
Hearing Loss ◽  
Traumatic Stress ◽  
High Frequency ◽  
Low Frequency ◽  
Treatment Programs ◽  
Post Traumatic Stress ◽  
Increased Risk ◽  
Before And After ◽  
Post Traumatic ◽  
New Onset

Abstract Introduction Mild TBI (TBI) is associated with up to a 75.7% incidence of tinnitus, and 33.0% of tinnitus patients at the US Veterans Administration carry a diagnosis of post-traumatic stress syndrome (PTSD). Yet factors contributing to new onset or exacerbation of tinnitus remain unclear. Materials and Methods Here we measure intermittent and constant tinnitus at two time points to ascertain whether pre-existing or co-occurring traumatic brain injury (TBI), hearing loss, or post-traumatic stress disorder (PTSD) predicts new onset, lack of recovery and/or worsening of tinnitus in 2,600 United States Marines who were assessed before and after a combat deployment. Results Ordinal regression revealed that constant tinnitus before deployment was likely to continue after deployment (odds ratio [OR] = 28.62, 95% confidence interval [CI]: 9.84,83.26). Prior intermittent tinnitus increased risk of post-deployment constant tinnitus (OR = 4.95, CI: 2.97,8.27). Likelihood of tinnitus progression increased with partial PTSD (OR = 2.39, CI: 1.50,3.80) and TBI (OR = 1.59, CI: 1.13,2.23), particularly for blast TBI (OR = 2.01, CI: 1.27,3.12) and moderate to severe TBI (OR = 2.57, CI: 1.46,4.51). Tinnitus progression also increased with low frequency hearing loss (OR = 1.94, CI: 1.05,3.59), high frequency loss (OR = 3.01, CI: 1.91,4.76) and loss across both low and high frequency ranges (OR = 5.73, CI: 2.67,12.30). Conclusions Screening for pre-existing or individual symptoms of PTSD, TBI, and hearing loss may allow for more focused treatment programs of comorbid disorders. Identification of those personnel vulnerable to tinnitus or its progression may direct increased acoustic protection for those at risk.

High-Frequency and Low-Frequency Oscillations in a Plasma in a Magnetic Field

1966 ◽  
Vol 21 (11) ◽  
pp. 2421-2421
Author(s):  
Kiyoe Kato ◽  
Takaya Kawabe ◽  
Mikiko Koganei ◽  
Eiich Kawasaki
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Low Frequency ◽  
Low Frequency Oscillations
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