To generate or maintain a turbulent flow, one needs to introduce kinetic energy. This energy injection necessarily fluctuates and these power fluctuations act on all turbulent excited length scales. If the power is injected using forces proportional to the velocity, such as those common in shear flows, or with a force acting at the largest scales only, the spectrum of these fluctuations is shown to have a universal inertial range, proportional to the energy spectrum.
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http://dx.doi.org/10.1103/PhysRevLett.122.124504 | DOI Listing |
Environ Monit Assess
January 2025
Bhaskaracharya College of Applied Sciences, University of Delhi, New Delhi, Delhi, 110078, India.
This study investigates the spatio-temporal distribution of formaldehyde (HCHO) over the mainland Southeast Asian region (including Northeast India) from 2019 to 2022 using TROPOMI satellite data. HCHO is a key atmospheric trace gas which is influenced by both natural processes and anthropogenic activities. We analyze HCHO levels in relation to atmospheric species including carbon monoxide (CO), nitrogen dioxide (NO), and environmental factors such as land surface temperature (LST), precipitation (PPT), fire radiative power (FRP), and enhanced vegetation index (EVI).
View Article and Find Full Text PDFPLoS One
January 2025
Computer Engineering, CCSIT, King Faisal University, Al Hufuf, Kingdom of Saudi Arabia.
This paper presents a low-power, second-order composite source-follower-based filter architecture optimized for biomedical signal processing, particularly ECG and EEG applications. Source-follower-based filters are recommended in the literature for high-frequency applications due to their lower power consumption when compared to filters with alternative topologies. However, they are not suitable for biomedical applications requiring low cutoff frequencies as they are designed to operate in the saturation region.
View Article and Find Full Text PDFSci Rep
January 2025
ENET Centre, CEET, VSB-Technical University of Ostrava, 708 00, Ostrava, Czech Republic.
Load frequency control (LFC) is critical for maintaining stability in interconnected power systems, addressing frequency deviations and tie-line power fluctuations due to system disturbances. Existing methods often face challenges, including limited robustness, poor adaptability to dynamic conditions, and early convergence in optimization. This paper introduces a novel application of the sinh cosh optimizer (SCHO) to design proportional-integral (PI) controllers for a hybrid photovoltaic (PV) and thermal generator-based two-area power system.
View Article and Find Full Text PDFJ Cataract Refract Surg
January 2025
Great Lakes Eye Care, Saint Joseph, MI, USA.
Purpose: To investigate the impact of the distance from the most-anterior surface of the optic to the principal object plane (POP) and from the foremost haptic to the principal object plane (H-POP) on the intraocular lens (IOL) power calculation.
Setting: A tertiary hospital.
Design: Optical simulation and retrospective cross-sectional study.
PNAS Nexus
January 2025
Faculty of Architecture, and Urban Systems Institute, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR.
Surfacic networks are structures built upon a 2D manifold. Many systems, including transportation networks and various urban networks, fall into this category. The fluctuations of node elevations imply significant deviations from typical plane networks and require specific tools to understand their impact.
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