A5048252320- Ocular and Laser Science Research
- Glaucoma and retinal disorders
- Cardiovascular Health and Disease Prevention
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Geophysics and Sensor Technology
- Earthquake Detection and Analysis
- Public Health and Environmental Issues
- Lightning and Electromagnetic Phenomena
- Social Sciences and Policies
- Solar Radiation and Photovoltaics
- Seismic Waves and Analysis
- Market Dynamics and Volatility
- Radio Astronomy Observations and Technology
- Stellar, planetary, and galactic studies
- Silicon and Solar Cell Technologies
- Fluid Dynamics and Turbulent Flows
- solar cell performance optimization
- Retinal Imaging and Analysis
- X-ray Diffraction in Crystallography
- Oil, Gas, and Environmental Issues
- Laser Design and Applications
- Electron and X-Ray Spectroscopy Techniques
South African National Space Agency
2016-2024
North-West University
2016-2022
University of Oulu
2022
National Institute for Theoretical Physics
2021
Hewlett-Packard (United States)
1985
Abstract In this study we examine the radial dependence of inertial and dissipation range indices, as well spectral break separating in power density spectra interplanetary magnetic field fluctuations using Parker Solar Probe data from fifth solar encounter between ∼0.1 ∼0.7 au. The derived wavenumber compares reasonably with previous estimates at larger distances is consistent gyro-resonant damping Alfvénic by thermal protons. We find that scale power-law index varies approximately −1.65...
Abstract We analyze the normal ( N ) component of heliospheric magnetic field observed by Interplanetary Monitoring Platform and Advanced Composition Explorer spacecraft for period 1973–2020. Parameters characterizing frequency spectrum are calculated with a novel technique, which is based on calculating variances at incremental lags to yield integral turbulence spectrum. compare this technique standard second-order structure function show their similarity in inertial range, use latter...
Abstract Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging highly dynamic coronal spanning a large range angular scales at wavelengths is extremely challenging. At gigahertz frequencies, MeerKAT telescope possibly globally best-suited instrument present for providing high-fidelity spectroscopic snapshot images. Here, we first published images Sun made using...
Abstract This study presents an improved method to estimate differential energy flux, auroral power and field‐aligned current of electron precipitation from incoherent scatter radar data. The is based on a newly developed data analysis technique that uses Bayesian filtering fit altitude profiles density, temperature, ion temperature observed spectra with high time range resolutions. are inverted the density profiles. Previous high‐time resolution fits have relied raw which calculated...
Abstract Black auroras are small-scale features embedded in the diffuse background aurora, typically occurring post-substorm after magnetic midnight and with an eastward drift imposed. show a significant reduction optical brightness compared to surrounding can appear as slow-moving arcs or rapidly-moving patches arc segments. We report, for first time, even more elusive structure that has always been observed paired $$\sim$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">...
A High Temperature Superconductor (HTS) SQUID magnetometer is located at the INTERMAGNET Hermanus Magnetic Observatory (HER) site in South Africa. The LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -cooled operated unshielded and records geomagnetic field continuously. If validated, may be used as a space weather instrument. small variations such pulsations, which are short period fluctuations of ULF frequencies. Although...
Earth’s magnetic field is a dynamic, changing phenomenon. The geomagnetic consists of contributions from several sources, which the main originating in core makes up bulk. On regional and local scales at surface, lithospheric can make substantial contribution to overall therefore needs be considered models. A locally derived model, named HMOREG, has been shown give accurate predictions southern African region. In this study, new model called South Regional Core Crust (SARCC) introduced. This...
SUMMARY Geomagnetic field data from six magnetic observatories in and adjacent to the South Atlantic Anomaly were individually analysed detect abrupt secular variation changes occurring on timescales of less than a year explore any correlation with evolution Anomaly. After applying external corrections by means CHAOS-7 model, 12-month differences respective observatory monthly mean eastward component Y revealed evidence several geomagnetic jerks varying amplitudes during period 2000–2020....
Abstract Using quasi‐simultaneous line‐of‐sight velocity measurements at multiple frequencies from the Hankasalmi Cooperative UK Twin Auroral Sounding System (CUTLASS) on Super Dual Radar Network (SuperDARN), we calculate electron number densities using a derivation outlined in Gillies et al. (2010, 2012). Backscatter targets were generated European Incoherent Scatter (EISCAT) ionospheric modification facility Tromsø, Norway. We use two methods case studies. The first approach is to...
X-ray diffraction experiments directly and nondestructively probe atomic scale structural correlations. When the samples are crystalline, x-ray scattering patterns may be obtained quickly show extremely high sensitivity to variations in order. topography methods specially arranged so as cover large sample areas efficiently. All of these features particularly useful semiconductor industry where careful control crystalline perfection nearly perfect materials is essential for device...
Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging highly dynamic coronal spanning a large range angular scales at wavelengths is extremely challenging. At GHz frequencies, MeerKAT telescope possibly globally best-suited instrument present for providing high-fidelity spectroscopic snapshot images. Here, we first published images Sun made using observations with in...
&lt;p&gt;Black auroras are small-scale features that show a significant reduction in optical brightness, i.e. reduced flux of particle precipitation, compared to the surrounding diffuse aurora. It typically occurs post-substorm after magnetic midnight. This phenomenon also exhibits lower mean energy than brighter aurora it is embedded in. The underlying mechanisms cause black not yet fully understood, although several theories have been proposed: coupled ionospheric-magnetospheric...