We present the results of an experimental investigation into the effects of a sinusoidal modulation of the rotation rate on the segregation patterns formed in thin drum of granular material. The modulation transforms the base pattern formed under steady conditions by splitting or merging the initial streaks. Specifically, the relation between the frequency of modulation and the rotation rate determines the number of streaks which develop from the base state. The results are in accord with those of Fiedor and Ottino [J. Fluid. Mech. 533, 223 (2005)10.1017/S0022112005003952], and we show that their ideas apply over a wide range of parameter space. Furthermore, we provide evidence that the observed relationship is maintained for filling fractions far from 50% and generalize the result in terms of the geometry of the granular deposit.
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http://dx.doi.org/10.1103/PhysRevE.90.052205 | DOI Listing |
Front Endocrinol (Lausanne)
January 2025
Center for Reproductive Medicine and Obstetrics and Gynecology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Background: Thin endometrial thickness (EMT) and advanced age are both common risk factors for adverse neonatal outcomes (ANOs). However, studies evaluating the impact of EMT and combined effect of EMT and age on ANOs remain scarce with conflicts.
Method: A retrospective cohort study was conducted on 7,715 singleton deliveries from frozen embryo transfer (FET) cycles between 2017 and 2021.
Sci Rep
January 2025
College of Mechanical and Electrical Engineering, Zhoukou Normal University, Zhoukou, 466000, China.
In order to study the movement characteristics of coal particles in the coal loading process of spiral drums, the spiral drum of a certain type of shearer was taken as the research object, and the intrinsic parameters of the materials were calibrated through the determination results of coal sample properties, the relevant parameters of coal particle adhesion were determined, and a discrete element model of spiral drum coal loading was established. The distribution of coal particle movement subsequent to the fracture of the coal wall was derived through simulation. By spatially dividing the envelope region of the spiral drum along the radial and axial directions, the number and velocity distribution of coal particles in different envelope regions were obtained.
View Article and Find Full Text PDFUltrasonics
February 2025
Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China; State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China. Electronic address:
Non-invasive, accurate diagnosis and treatment have increasingly gained attention in medical research. The nonlinear response mechanism of ultrasound contrast agents and their medical application have become major topics in ultrasound imaging studies. This paper reports on a second-harmonic focused ultrasonic device based on micro-bubble contrast agents, which is designed to solve the problems associated with a weak second-harmonic intensity.
View Article and Find Full Text PDFSci Adv
September 2024
Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA.
A weak van der Waals (vdW) force in layered materials enables their isolation into thin flakes through mechanical exfoliation while sustaining their intrinsic electronic and optical properties. Here, we introduce a universal roll-printing method capable of producing vdW multilayer films on wafer-to-meter scale. This process uses sequential exfoliation and transfer of layered materials from the powder sources to target substrates through a repeated rolling of a cylindrical metal drum.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2024
State Key Laboratory of Analytical Chemistry for Life Science and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
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