High Magnetic Field Strength Research Articles

Investigating explosive events in a 3D quiet-Sun model: Transition region and coronal response

Transition region explosive events are characterized by the non-Gaussian profiles of the emission lines that form at transition region temperatures, and they are believed to be manifestations of small-scale reconnection events in the transition region. Traditionally, the enhanced emission at the line wings is interpreted as bi-directional outflows generated by the reconnection of oppositely directed magnetic fields. We investigate whether the 2D picture also holds in a more realistic setup of a 3D radiation magnetohydrodynamic (MHD) quiet-Sun model. We also compare the thermal responses in the transition region and corona of different events. We took a 3D self-consistent quiet-Sun model extending from the upper convection zone to the lower corona calculated using the MURaM code. We first synthesized the Si iv line profiles from the model and then located the profiles which show signatures of bi-directional flows. These tend to appear along network lanes, and most do not reach coronal temperatures. We isolated two hot events (around 1 MK) and one cool event (order of 0.1 MK) and examined the magnetic field evolution in and around these selected events. Furthermore, we investigated why some explosive events reach coronal temperatures, while most remain cool. We also examined the emission of these events as seen in the 174 AA passband of the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter and all coronal passbands of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). The field lines around two events reconnect at small angles (i.e., they undergo component reconnection). The third case is associated with the relaxation of a highly twisted flux rope. All three events reveal signatures in the synthesized EUI 174 AA images. The intensity variations in two events are dominated by variations of the coronal emissions, while the cool component seen in the respective channel contributes significantly to the intensity variation in one case. In comparison, one hot event is embedded in regions with higher magnetic field strength and heating rates while the densities are comparable, and the other hot event is heated to coronal temperatures mainly because of the low density. Small-scale heating events seen in the extreme-ultraviolet (EUV) channels of AIA or EUI might be hot or cool. Our results imply that the major difference between the events in which coronal counterparts dominate or not is the amount of converted magnetic energy and/or density in and around the reconnection region.

UGMRT Survey of EXoplanets Around M-dwarfs (GS-EXAM): Radio Observations of GJ 1151

Coherent radio emission with properties similar to planetary auroral signals has been reported from GJ 1151, a quiescent, slow-rotating mid-M star, by the LOFAR Two-meter (120–170 MHz) Sky Survey. The observed LOFAR emission is fairly bright at 0.89 mJy with 64% circular polarization, and the emission characteristics are consistent with the interaction between an Earth-sized planet with an orbital period of 1–5 days and the magnetic field of the host star. However, no short-period planet has been detected around GJ 1151. To confirm the reported radio emission caused by the putative planet around GJ 1151 and to investigate the nature of this emission, we carried out upgraded Giant Metrewave Radio Telescope observations of GJ 1151 at 150, 218, and 400 MHz over 33 hr across ten epochs. No emission was detected at any frequency. While at 150 and 218 MHz, nondetection could be due to the low sensitivity of our observations, at 400 MHz, the rms sensitivities achieved were sufficient to detect the emission observed with LOFAR at ∼20σ level. Our findings suggest that the radio emission is highly time variable, likely influenced by the star-planet system’s phase and the host star’s magnetic field. Additional observations below 170 MHz, at more frequent epochs (as the periodicity of the emission is unknown), especially during periods of high stellar magnetic field strength, are needed to confirm the emission.

The significance of magnetized thermal radiation on the magnetohydrodynamic (MHD) behavior of Williamson hybrid ferrofluids over a stretching sheet

The goal of this study is to investigate the fluid dynamics of a pseudoplastic Williamson nanofluid model, explicitly focusing on blood infused with magnetite (Fe2O3) and (Cu) copper nanoparticles, with the aim of enhancing its physiological and industrial applications. This research offers a novel approach by integrating the Williamson fluid model with magnetic nanoparticles, which has not been widely explored in biomedical applications like antitumor therapy and magnetic hyperthermia. The study is mathematically modeled using partial differential equations (PDEs) accounting for the deformation vortices of a stretching surface. These governing equations are transformed into ordinary differential equations (ODEs) via similarity transformations and solved numerically using the Runge-Kutta (R-K) 4th-order method coupled with the shooting technique. The velocity and temperature fields are then analyzed through MATLAB simulations. Results indicate that increasing the Williamson, radiation, and nanoparticle volume fraction parameters elevates the fluid temperature, whereas higher magnetic field strength, Prandtl number, and stretching parameter values reduce it. The novelty of this work lies in its application of the Williamson nanofluid model to real-time medical applications, such as cancer treatment through magnetic hyperthermia, and its potential use in advanced biomedical devices.

Synthetic measurements of runaway electron synchrotron emission in the SPARC tokamak.

With plasma currents up to 8.7 MA, the SPARC tokamak runs the risk of forming multi-MA beams of relativistic "runaway" electrons (REs), which could damage plasma facing components if unmitigated. The infrared (IR) and visible imaging and visible spectroscopy systems in SPARC are designed with measurements of synchrotron emission from REs in mind. Synchrotron radiation is emitted by REs along their direction of motion, opposite the plasma current. Matched clockwise and counterclockwise wide views are proposed to detect synchrotron and background radiation, allowing observation of RE synchrotron emission in both plasma current configurations. Due to SPARC's high toroidal magnetic field strength, 12.2T on axis, the synchrotron light spectrum is expected to peak in the visible-IR wavelength range. The synthetic diagnostic tool, Synchrotron Orbit-Following Toolkit, is used to model synchrotron images and spectra for three scenarios, with appropriate magnetic equilibria for each: REs generated during plasma current ramp-up, steady-state flat-top (although unlikely, but serving as a reference), and disruptions. Required time resolutions, achievable spatial coverage, and appropriate spectral ranges for various RE energies are assessed.

Design and optimization of a novel solenoid with high magnetic uniformity

Currently, solenoids are extensively utilized in various research fields due to their flexibility of fabrication and high magnetic field strength. However, the internal magnetic field of the solenoid itself exhibits some non-uniformity defects, which limits its application in some domains. This article proposes a novel single winding tightly wound solenoid structure with an improved magnetic field uniformity. To optimize the magnetic field near the aperture of the conventional solenoid, an auxiliary solenoid with a gradually changing diameter is included at each end of the solenoid. By adjusting different parameters of the auxiliary solenoid, the edge effect of the solenoid was reduced, and its overall magnetic field uniformity was improved. The optimization of the auxiliary solenoids is achieved through GA-KAN network techniques. Finite element simulation results with the optimized parameters show that the proportion of uniform areas can be improved by more than five times. The research results are a reference for high-precision electromagnetic sensing applications based on solenoids.

Interplanetary Causes and Impacts of the 2024 May Superstorm on the Geosphere: An Overview

The recent superstorm of 2024 May 10–11 is the second largest geomagnetic storm in the space age and the only one that has simultaneous interplanetary data (there were no interplanetary data for the 1989 March storm). The May superstorm was characterized by a sudden impulse (SI+) amplitude of +88 nT, followed by a three-step storm main-phase development, which had a total duration of ∼9 hr. The cause of the first storm main phase with a peak SYM-H intensity of −183 nT was a fast-forward interplanetary shock (magnetosonic Mach number M ms ∼ 7.2) and an interplanetary sheath with a southward interplanetary magnetic field component B s of ∼40 nT. The cause of the second storm's main phase with an SYM-H intensity of −354 nT was a deepening of the sheath B s to ∼43 nT. A magnetosonic wave (M ms ∼ 0.6) compressed the sheath to a high magnetic field strength of ∼71 nT. Intensified B s of ∼48 nT were the cause of the third and most intense storm main phase, with an SYM-H intensity of −518 nT. Three magnetic cloud events with B s fields of ∼25–40 nT occurred in the storm recovery phase, lengthening the recovery to ∼2.8 days. At geosynchronous orbit, ∼76 keV to ∼1.5 MeV electrons exhibited ∼1–3 orders of magnitude flux decreases following the shock/sheath impingement onto the magnetosphere. The cosmic-ray decreases at Dome C, Antarctica (effective vertical cutoff rigidity <0.01 GV) and Oulu, Finland (rigidity ∼0.8 GV) were ∼17% and ∼11%, respectively, relative to quiet-time values. Strong ionospheric current flows resulted in extreme geomagnetically induced currents of ∼30–40 A in the subauroral region. The storm period is characterized by strong polar-region field-aligned currents, with ∼10 times intensification during the main phase and equatorward expansion down to ∼50° geomagnetic (altitude-adjusted) latitude.

Radiation therapy systems using linear accelerator, importance of its components and their development

Given the importance of devices used in the field of medicine in terms of diagnosis and treatment, and the great importance of this topic in accelerating early diagnosis and saving the lives of the largest possible number of people, we decided to study one of these devices to better define its components and review some of the difficulties. Many linear accelerators for hybrid magnetic resonance imaging have been developed as a result of the need to profit from directed images of tissues and various body sections during radiation therapy (linear accelerators). There are now a number of linear accelerators for magnetic resonance imaging that cover both low and high magnetic field strengths as well as two directions of the beam field; these systems have the potential to be beneficial. This technology has only recently been used in clinical trials. However, its continued usage as a routine radiation therapy procedure is certain. The majority of the key elements and difficulties encountered in the creation of such technology as well as its present state are outlined in this review article.

Exploring the potential of a setup for combined quantification of hydrogen in natural gas – Raman and NMR spectroscopy

An accurate measurement of the amount fraction of hydrogen in gas mixtures is mandatory for practical applications, requiring methods that are fast, continuous, robust, and cost-effective. This study compares the performance of Raman and benchtop NMR process spectroscopy for determining the hydrogen amount fraction in gas mixtures. A setup was designed to integrate both techniques, enabling measurements of the same sample. Tests were conducted with gravimetrically prepared gas mixtures of reference quality ranging from 1.20 cmol/mol to 85.83 cmol/mol of hydrogen. The results demonstrate that Raman spectroscopy provides superior performance, with a minimal root mean square error (RMSE) of 0.22 cmol/mol and excellent linearity. In contrast, benchtop NMR spectroscopy faced challenges, such as overlapping peaks and longer measurement times, resulting in a higher RMSE of 0.71 cmol/mol. Raman spectroscopy proves to be particularly well-suited for practical applications due to its high accuracy and linearity. Meanwhile, benchtop NMR spectroscopy holds potential for future enhancements through ongoing technological advances, such as higher magnetic field strengths. In summary, the results from our study indicate that Raman spectroscopy is already a serviceable method for precise hydrogen quantification, whereas benchtop NMR spectroscopy can be attributed potential for future applications.

Radiation RMHD Accretion Flows around Spinning AGNs: A Comparative Study of MAD and SANE State

In our study, we examine a 2D radiation, relativistic, magnetohydrodynamics accretion flow around a spinning supermassive black hole. We begin by setting an initial equilibrium torus around the black hole, with an embedded initial magnetic field inside the torus. The strength of the initial magnetic field is determined by the plasma beta parameter, which is the ratio of the gas pressure to the magnetic pressure. In this paper, we perform a comparative study of the magnetically arrested disc (MAD) and standard and normal evolution (SANE) states. We observe that the MAD state is possible for comparatively high initial magnetic field strength flow. Additionally, we also adopt a self-consistent two-temperature model to evaluate the luminosity and energy spectrum for our model. We observe that the total luminosity is mostly dominated by bremsstrahlung luminosity compared to the synchrotron luminosity due to the presence of a highly dense torus. We also identify similar quasi-periodic oscillations for both MAD and SANE states based on power-density spectrum analysis. Furthermore, our comparative study of the energy spectrum does not reveal any characteristic differences between MAD and SANE states. Last, we note that the MAD state is possible for both prograde and retrograde accretion flow.

(Invited) The Influence of Magnetic Fields on the Oxygen Evolution Reaction Catalyzed By Cobalt-Iron Oxide Nanowire Arrays

To mitigate climate change through the establishment of a renewable energy infrastructure, advancements in energy storage technologies are imperative. Electrochemical water splitting via electrolyzers enables the conversion of electrical energy into chemical energy. However, the performance of these devices, particularly that of the oxygen evolution reaction (OER) occurring at the anode, still needs to be improved. Previous studies have demonstrated that magnetic fields can induce convective flow to the electrode through Lorentz and Kelvin force effects, thereby improving the mass transport.[1] In contrast to the Lorentz force, the Kelvin force can be substantially increased by introducing magnetic nanostructures to create high magnetic field gradients in the vicinity of the electrode surface.[2] Given the magnetic properties inherent to many earth-abundant metal-based and nanostructured electrocatalysts promising for the OER, there is potential for intelligently designing electrodes to leverage magnetic field effects in the future. However, a comprehensive understanding of these magnetic field effects is currently lacking. In the scope of this work, we aimed to systematically investigate the influence of magnetic fields on the oxygen evolution reaction. Considering the substantial magnetic field gradients generated by magnetic nanowires, we fabricated arrays of freestanding cobalt-iron oxide nanowires to explore the influence of magnetic fields on the oxygen evolution reaction catalyzed by these nanostructured electrocatalysts. Templated electrodeposition of cobalt-iron alloy into the pores of anodic aluminum oxide membranes enabled a straightforward control over nanowire diameter and length. Subsequent removal of the aluminum oxide template in alkaline solution yielded cobalt-iron oxide nanowires composed to 60% of Fe and 40% of Co standing freely on an electrochemically stable gold substrate. Superimposing a magnetic field during water oxidation on the so-prepared nanowire arrays resulted in an increase in the measured oxidation current (see Figure). To deconvolute the contributions of the Lorentz and Kelvin force, experiments were conducted in two different magnetic field orientations: either parallel or perpendicular to the electrode surface. In the parallel orientation, a linear correlation between the increase in current and the strength of the applied magnetic field was observed. In contrast, when the magnetic field was aligned perpendicular to the electrode surface, a plateau in the current enhancement manifested at higher magnetic field strengths, indicating different dominant effects in the two configurations.[1] K. Ngamchuea, K. Tschulik, R. G. Compton, Magnetic control: Switchable ultrahigh magnetic gradients at Fe3O4 nanoparticles to enhance solution-phase mass transport, Nano Res. 2015, 8, 3293–3306.[2] L. M. Monzon, J. Coey, Magnetic fields in electrochemistry: The Kelvin force. A mini-review, Electrochem. commun. 2014, 42, 42–45. Figure 1

The motional Stark effect diagnostic for ITER.

An overview of the plans for the motional Stark effect (MSE) diagnostic installation on the International Thermonuclear Experimental Reactor (ITER) is presented. The MSE diagnostic uniquely provides spatially localized magnetic field measurements inside the plasma. These are used to constrain equilibrium reconstructions to determine q(r), the safety factor as a function of minor radius. Meeting the system requirements to deliver q-profiles and related quantities with the specified radial resolution of 20 points over the minor radius, 10ms time resolution, and better than 10% accuracy is challenging. MSE systems observe the D/H-α emission near 656.3nm from neutral beams. As the beam atoms traverse the magnetic field, B⃗, at high velocity, v⃗, they experience a Lorentz electric field, v⃗×B⃗, which causes the spectral emission to be split and polarized due to the Stark effect. Traditional MSE-LP (line polarization) measurements determine the direction of the magnetic field in the observation volume using polarimetric analysis of the detected light. The harsh conditions of ITER are expected to deposit thin films of contaminants on the first mirror, which would alter the polarization state of reflected light significantly. On ITER, the combination of high magnetic field strength and high energy beams makes the Stark spectrum resolution suitable for the determination of the magnetic field magnitude from the line shift, so this approach has been selected. Every aspect of the measurement system must be planned for the burning plasma environment and carefully analyzed ahead of time. Current status and plans for the system are presented.

Improvement of plastic deformation property and current carrying capacity of Bi2212 wires through low oxygen partial pressure post-annealing of precursor

The performance of superconducting magnets is greatly dependent on the size and uniformity of the superconducting filaments within the wire. However, in the fabrication of Bi2Sr2CaCu2Ox (Bi2212) wires using ceramic oxide as the superconducting filaments, we face multiple challenges including filament fragility, poor uniformity, and non-smooth Ag/superconductor interfaces. These challenges primarily stem from the significantly lower plastic deformation capability of ceramic oxide powder filaments compared to metal matrices. To address these challenges, this study focuses on the modification of ceramic oxide precursor powders. Through the utilization of low-temperature, low oxygen partial pressure (pO2) heat treatment, we have observed significant changes in the Cu chemical states and lattice parameters within the Bi2212 grains. These alterations have proven to be highly effective in reducing the energy required for grain sliding and, in turn, enhancing the plastic deformation properties of the Bi2212 oxide filament. Furthermore, post-annealing the oxide powder under low pO2 conditions narrows the gap in plastic deformability between the Ag sheath and the oxide filaments, resulting in improved filament uniformity and a smoother Ag/oxide interface in Bi2212 wires. Notably, the Bi2212 grains exhibit an orderly arrangement within the wires. As a result of these improvements, the critical current density (Jc) of the final wires increases by an impressive 70 %. The outcomes of this study are not only crucial for producing Bi2212 magnets with higher magnetic field strength, improved magnetic field uniformity, and enhanced operational stability, but also offer fresh insights and methodologies for advancing the field of superconducting materials.

The Optimization of Microwave Field Characteristics for ODMR Measurement of Nitrogen-Vacancy Centers in Diamond

A typical solid-state quantum sensor can be developed based on negatively charged nitrogen-vacancy (NV−) centers in diamond. The electron spin state of NV− can be controlled and read at room temperature. Through optical detection magnetic resonance (ODMR) technology, temperature measurement can be achieved at the nanoscale. The key to ODMR technology is to apply microwave resonance to manipulate the electron spin state of the NV−. Therefore, the microwave field characteristics formed near the NV− have a crucial impact on the sensitivity of ODMR measurement. This article mainly focuses on the temperature situation in cellular applications and simulates the influence of structural parameters of double open loop resonant (DOLR) microwave antennas and broadband large-area (BLA) microwave antennas on the microwave field’s resonance frequency, quality factor Q, magnetic field strength, uniformity, etc. The parameters are optimized to have sufficient bandwidth, high signal-to-noise ratio, low power loss, and high magnetic field strength in the temperature range of 36 °C to 42.5 °C. Finally, the ODMR spectra are used for effect comparison, and the signal-to-noise ratio and Q values of the ODMR spectra are compared when using different antennas. We have provided an optimization method for the design of microwave antennas and it is concluded that the DOLR microwave antenna is more suitable for living cell temperature measurement in the future.

Effects of selected cathode materials on a magnetically enhanced vacuum arc thruster

We discuss the effects of the ion distribution of a magnetically-enhanced Vacuum Arc Thruster using different cathode materials (Fe, Al, Cu) and magnetic field strengths. We develop a formalism, which is based on physical and geometric ideas, that describes the data for the inclusion of a magnetic field better than previous models (R2 > 0.89 for worst case). Our tests were performed on a Vacuum Arc Thruster with 270 A discharge current and an average pulse length of 3.5 ms. The magnetic field generator, driven by a separate capacitive discharge circuit, produced field strengths ranging from 0 to 250 mT along the thruster's centerline. We obtained the thrust correction factor and theoretical thrust from our measurements. It was found that application of magnetic fields increased ion density and axial momentum along the plasma plume's centerline. At higher magnetic field strengths (∼250 mT) the thrust factor decreased across all materials. For our electrodes, the inclusion of a protruding magnetic nozzle was seen to cancel the benefits arising from beam collimation due to the magnetic field. The iron electrode performed best, which may be due to its ferromagnetic nature.

Precipitation mechanism of abrasive particles in magnetorheological polishing fluid and experimental verification

This study aims to address the issue of poor workpiece surface machining quality due to inadequate abrasive particle precipitation during the processing of magnetorheological polishing fluid. The paper employs magnetic dipole theory and molecular dynamics theory to establish a microdynamics model for magnetorheological polishing fluid and conducts kinematic and dynamic analyses of magnetic and abrasive particles. The chaining process of magnetic particles in magnetorheological polishing fluid was simulated under an external magnetic field, and the precipitation process of abrasive particles under the action of magnetic particles was simulated and analyzed. Furthermore, we established a microscopic observation experimental platform for magnetorheological polishing fluid and verified the precipitation law of abrasive particles under the action of dynamic magnetic field. The study findings indicate that the magnetic particles will form a chain structure, when the rotating magnetic field has an effect on the magnetorheological polishing fluid, and the abrasive particles will precipitate from the magnetorheological polishing fluid and adhere to the upper end of the magnetic chain. Moreover, the precipitation rate of abrasive particles is also affected by the magnetic field strength, the volume fraction of magnetic particles, and the rotating magnetic field speed, with the abrasive particles’ precipitation rate specifically increasing with higher magnetic field strength. At a magnetic field strength of 100 kA/m, the abrasive precipitation rate reaches 80 % in approximately 90 s, which increases to 80 % in only 60 s at a magnetic field strength of 200 kA/m. Additionally, with the increase of magnetic particle volume fraction, the precipitation rate of abrasive particles decreases. Within the first 40 s of the test, the magnetic particle volume fraction increases from 10 % to 30 %, and the precipitation rate of abrasive particles decreases by about 11 %. Similarly, the abrasive precipitation rate is affected differently by the rotating magnetic field speed. As the rotating magnetic field speed increases, the abrasive precipitation rate shows a trend of first increasing and then decreasing. When the rotating magnetic field speed increases from 20 r/min to 40 r/min, the abrasive precipitation rate of the first 40 s increases by about 25 %. When the speed continues to increase to 60 r/min, the precipitation rate of abrasive particles gradually decreases.

Investigation of high field plasma dynamics in a laser-produced plasma expanding into a background gas

This paper presents an overview of experimental results of a laser-produced plasma expanding into a background gas, immersed within a large range of highly uniform magnetic fields (of up to 3 T), that are transverse to the expanding plasma. We used intensified gated imaging to capture the expansion of the plasma across and along the magnetic field lines to observe the spatiotemporal expansion dynamics for different magnetic field strengths. We observe changes in the perpendicular and parallel dynamics of the laser-produced plasmas expansion at high magnetic field. In addition, our results have also indicated the presence of electron-ion hybrid instabilities at relatively high pressures (100 mTorr) and relatively high magnetic field strengths (2 T), in accordance with theoretical calculations.

Cross‐Comparison of Observations With the Predictions of Global Hybrid Simulations for Multiple IMF Discontinuities Impacting the Bow Shock and Magnetosheath

AbstractWe use the three‐dimensional (3‐D) global hybrid code ANGIE3D to simulate the interaction of four solar wind tangential discontinuities (TDs) observed by ARTEMIS P1 from 0740 UT to 0800 UT on 28 December 2019 with the bow shock, magnetosheath, and magnetosphere. We demonstrate how the four discontinuities produce foreshock transients, a magnetosheath cavity‐like structure, and a brief magnetopause crossing observed by THEMIS and MMS spacecraft from 0800 UT to 0830 UT. THEMIS D observed entries into foreshock transients exhibiting low density, low magnetic field strength, and high temperature cores bounded by compressional regions with high densities and high magnetic field strengths. The MMS spacecraft observed cavities with strongly depressed magnetic field strengths and highly deflected velocity in the magnetosheath downstream from the foreshock. Dawnside THEMIS A magnetosheath observations indicate a brief magnetosphere entry exhibiting enhanced magnetic field strength, low density, and decreased and deflected velocity (sunward flow). The solar wind inputs into the 3‐D hybrid simulations resemble those seen by ARTEMIS. We simulate the interaction of four oblique TDs with properties similar to those in the observation. We place virtual spacecraft at the locations where observations were made. The hybrid simulations predict similar characteristics of the foreshock transients, a magnetosheath cavity, and a magnetopause crossing with characteristics similar to those observed by the multi‐spacecraft observations. The detailed and successful comparison of the interaction involving multiple TDs will be presented.

Fargo: validation of space-relevant ferrofluid applications on the ISS

The Ferrofluid Application Research Goes Orbital (FARGO) project desires to harness the potential of ferrofluids for advanced space system applications. Thereby, the student-led research project aims to develop, evaluate and subsequently validate three different ferrofluid-based applications on board the International Space Station (ISS): a novel attitude control system called Ferrowheel as well as a Thermal and an Electrical Switch. The project is part of the Überflieger2 competition of the German Aerospace Center (DLR) in cooperation with the Luxembourg Space Agency (LSA). Central to this study is the role of ferrofluids in ensuring the functional principles to minimize the number of moving components ultimately. Therefore, the proposed systems have the potential to mitigate wear, reduce friction, and consequently improve the longevity and reliability of space systems. In the Ferrowheel, a disc is supported on ferrofluid cushions instead of conventional ball-bearing-mounted rotors. This innovative approach, facilitated by the magnetic pressure positioning of the ferrofluid, eliminates the need for solid-to-solid contact. Circularly arranged coils function as the stator, propelling the disc with a 3-phase control, resulting in a spinning magnetic field. In addition to determining the generated torque, the objective is to validate experiments on system operations in which various acceleration and deceleration manoeuvres, as well as the stored angular momentum, are evaluated. The Electrical Switch leverages a self-manufactured magnetorheological fluid (MRF) developed by augmenting a liquid–metal base with iron powder. As a result, the fluid, akin to ferrofluid, has a magnetic field-responsive movement. Since a liquid metal is used as the base, the ferrofluid-like fluid acts as both the magnetically actuatable and the current conducting fluid. To enable a current flow, the fluid is brought between the two electrical contacts utilizing electropermanent magnets (EPMs). These magnets combine the high magnetic field strengths of permanent magnets with the adaptive switching capability of electromagnets. Compared to all other demand-controlled magnetic field sources, this results in the great advantage that no energy is consumed as long as they are in one state. Only the switching process of the EPMs itself requires a high amount of energy, but only for a relatively short period. The switching behaviour under different loads will be investigated, evaluated, and compared to reference data recorded on Earth. The design of the Thermal Switch is characterized by the fact that it can be actively switched. Active thermal switching is still a relatively new field, so there is little comparative data from industrial solutions. Particularly for spacecraft, thermal design is crucial because the harsh environment of space must be taken into account. In addition to the challenge that heat can only be transferred to the environment via thermal radiation, severe conditions in space are characterized by extreme temperature differences. While extreme heat develops on the satellite surface on the side facing the sun, the opposite is valid on the shaded side. The resulting heat flow, which is irregular in time, location, and direction, leads to temperature peaks and gradients that can affect the system’s performance, functionality, and reliability. Active switching provides selective control over heat transfer, allowing more flexible temperature regulation in critical areas and implementing a dynamic system response. Different design ideas are tested and evaluated for the applications in various experiments. The most suitable design is finally selected, further modified, and tailored for experimentation on the ISS and presented in this study. The most significant challenge is the time-critical factor of only a 1-year development phase. A total of 21 students from six different courses of study and two supervising PhD students from the Institute of Space Systems are involved in the FARGO project, all members of the small satellite student society at the University of Stuttgart, KSat e.V.

Comparison of dynamic susceptibility contrast (DSC) using gadolinium and iron-based contrast agents in high-grade glioma at high-field MRI.

To compare DSC-MRI using Gadolinium (GBCA) and Ferumoxytol (FBCA) in high-grade glioma at 3T and 7T MRI field strengths. We hypothesized that using FBCA at 7T would enhance the performance of DSC, as measured by contrast-to-noise ratio (CNR). Ten patients (13 lesions) were assigned to 3T (6 patients, 6 lesions) or 7T (4 patients, 7 lesions). All lesions received 0.1mmol/kg of GBCA on day 1. Ten lesions (4 at 3T and 6 at 7T) received a lower dose (0.6mg/kg) of FBCA, followed by a higher dose (1.0-1.2mg/kg), while 3 lesions (2 at 3T and 1 at 7T) received only a higher dose on Day 2. CBV maps with leakage correction for GBCA but not for FBCA were generated. The CNR and normalized CBV (nCBV) were analyzed on enhancing and non-enhancing high T2W lesions. Regardless of FBCA dose, GBCA showed higher CNR than FBCA at 7T, which was significant for high-dose FBCA (p < .05). Comparable CNR between GBCA and high-dose FBCA was observed at 3T. There was a trend toward higher CNR for FBCA at 3T than 7T. GBCA also showed nCBV twice that of FBCA at both MRI field strengths with significance at 7T. GBCA demonstrated higher image conspicuity, as measured by CNR, than FBCA on 7T. The stronger T2* weighting realized with higher magnetic field strength, combined with FBCA, likely results in more signal loss rather than enhanced performance on DSC. However, at clinical 3T, both GBCA and FBCA, particularly a dosage of 1.0-1.2mg/kg (optimal for perfusion imaging), yielded comparable CNR.

The search for new pathogenesis of cardiorenal syndrome: the effect of local Schumann resonance on the occurrence of episodes of kidney disease and myocardial infarction

Background. The pandemic of noncommunicable chronic diseases and the high prevalence of combined damage to the cardiovascular system and kidneys determine the relevance of continuing scientific research to solve these medical problems. Therefore, the aim of this study was to compare the influence of the Earth’s electromagnetic field on the occurrence of episodes of kidney disease and myocardial infarction in order to search for new pathogenetic components of cardiorenal syndrome and deepen fundamental knowledge. According to the Lithuanian magnetometer GCI003, a number of stu­dies in 2014–2018 found that changes in the Earth’s electromagnetic field may play an important role in the pathogenesis of cardiovascular diseases as well as their incidence. Since the functioning of the cardiovascular system and kidneys are closely connected through the metabolic processes of the cardiorenal metabolic axis, this study tested the hypothesis that changes in the Earth’s electromagnetic field may also affect the pathogenesis of kidney disease as the changes of local magnetic field have been shown to influence the functioning of the cardiovascular system. Materials and methods. This was a search retrospective study on the relationship between the influence of local Schumann resonances and the occurrence of hospitalizations in 1340 patients with kidney disease. It also examined the relationship between local Schumann resonances and heart attacks in patients admitted to the University Hospital of the Lithuanian University of Health Sciences (703 patients). Mean power of local magnetic field fluctuations in Lithuania was measured in pT2 s2 in five different frequency ranges, which overlaps the Schumann resonance and electroencephalogram’s frequency ranges: SDelta (0–3.5 Hz), STheta (3.5–7 Hz), SAlpha (7–15 Hz), SBeta (15–32 Hz), SGamma (32–66 Hz). The data of hospitalizations to the Nephrology Department of University Hospital and the dynamics of Schumann resonances were analyzed from January 1, 2021 to December 31, 2021. The data of hospitalizations for myocardial infarction to the Cardiology Department of University Hospital and the dynamics of Schumann resonances were studied from January 1, 2016 to December 31, 2016. Results. It was found that changes in the strength of the Earth’s local magnetic field in 2016 and 2021 were comparable and corresponded to the characteristic annual dynamics of the Earth’s local electromagnetic fields. This made it possible to conduct a comparative analysis of annual correlation graphs and establish general trends in the dynamics of indicators and graphical similarities. It confirmed the pre­sence of a general dependence of reactions to the external electromagnetic field of the Earth in female and male patients both with nephrological pathology and myocardial infarction. In nephrological patients of both sexes, all correlation coefficients in all ranges of Schumann resonances were positive. The only negative correlation coefficient P5 (SGamma) [32; 65] Hz (r = –0.069; p = 0.313) was in the female group. This fact as well as the presence of a significant dynamics of the correlation coefficient P5 (SGamma) [32; 65] Hz (r = 0.009; p = 0.475) in the male group indicate that higher magnetic field strength in this frequency range may be associated with a reduced incidence of kidney disease. We obtained data that a higher magnetic field intensity in the gamma range from 32 to 65 Hz as a pathogenetic component can contribute to the destabilization of the cardiovascular system, but at the same time it is associated with a positive effect on the state of nephrological pathology. Based on this, we can tentatively assume the opposite direction of the Earth’s electromagnetic field influence on the pathogenetic mechanisms of renal and cardiovascular diseases. This is clearly demonstrated by comparing the correlation coefficients between the incidence of kidney disease and the occurrence of myocardial infarction in men and women. The Earth’s stronger magnetic field in the gamma range contributes to an increase in the incidence of myocardial infarction, which is confirmed by the large number of patients during this period. Under these same conditions, a decrease in the incidence of kidney disease has been detected. This opposite direction is observed in both sexes. But in women the reaction is stronger, which is confirmed by a larger difference in correlation coefficients. Conclusions. 1. Changes in the Earth’s electromagnetic field are related to the functional state of the cardiovascular system and the condition of the kidneys. 2. It can be assumed that the effect of the Earth’s electromagnetic field on the pathogenetic mechanisms of kidney disease is in the opposite direction of that on the cardiovascular one. 3. Reliable gender differences in correlations between the influence of changes in the local Schumann resonance on the functional state of the cardiovascular system and kidneys were not found. 4. The connection of the Earth’s local geomagnetic field with kidney function may be another new unexplored pathogenetic mechanism in cardiorenal syndrome and noncommunicable chronic diseases.