We present the results of an experimental investigation of the dynamics of droplets bouncing on a vibrating fluid bath for forcing accelerations above the Faraday threshold. Two distinct fluid viscosity and vibrational frequency combinations (20 cS-80 Hz and 50 cS-50 Hz) are considered, and the dependence of the system behavior on drop size and vibrational acceleration is characterized. A number of new dynamical regimes are reported, including meandering, zig-zagging, erratic bouncing, coalescing, and trapped regimes. Particular attention is given to the regime in which droplets change direction erratically and exhibit a dynamics akin to Brownian motion. We demonstrate that the effective diffusivity increases with vibrational acceleration and decreases with drop size, as suggested by simple scaling arguments.
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Faraday Discuss
February 2025
Department of Civil and Environmental Engineering, NTNU, Trondheim, Norway.
The permeability of sea ice is difficult to observe, and physically based permeability models are lacking so far. Here a model for the permeability of sea ice is presented that combines extensive microstructure observations and modelling with directed percolation theory. The model predicts the dependence of sea ice permeability on brine porosity and growth rate, as well as a percolation transition to impermeable sea ice due to necking of the pores.
View Article and Find Full Text PDFJ Am Coll Cardiol
January 2025
Baylor Heart and Vascular Institute, Dallas, Texas, USA; Imperial College, London, United Kingdom.
Patient-reported health status is an important assessment of patients with heart failure, but current approaches have substantial methodological and analytical limitations. Changes in the Kansas City Cardiomyopathy Questionnaire (KCCQ) are commonly presented as a measure of the effect of drugs and devices, most often as the between-group difference in population means or as the odds of showing threshold changes of 5, 10, 15, and 20 points. However, the presentation of mean differences is based on statistical assumptions that are routinely violated in most trials.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
State Key Laboratory of Electroanalytical Chemistry, Jilin Province Key Laboratory of Low Carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, China; School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China. Electronic address:
Background: Scanning electrochemical microscopy (SECM) is a kind of scanning probe technology that enables the obtainment of surface morphology and electrochemical information by recording changes in Faraday current triggered by the movement of probe.
Results: In this work, flexible disk ultramicroelectrode (UME) with highly repeatable geometry are fabricated through a simple and universal strategy that involves vacuum pulling the glass capillaries inserted with platinum wire (gold wire, carbon fiber, etc.), followed by a rapidly heated sealing and polishing process.
Faraday Discuss
February 2025
Laboratoire de Chimie Physique et Microbiologie pour les Matériaux et l'Environnement (LCPME), Université de Lorraine, CNRS, Nancy 54000, France.
The recent developments in scanning electrochemical probe techniques focus on the strategy of scanning the electrolyte. For example, scanning electrochemical cell microscopy (SECCM) is based on holding the electrolyte in a glass capillary, while scanning gel electrochemical microscopy (SGECM) immobilizes the gel electrolyte on micro-disk electrodes or etched metal wires. In both SECCM and SGECM, the first and essential step is to bring the electrolyte probe into contact with the sample, which is very often achieved by current feedback with a constant applied potential between the probe and the sample.
View Article and Find Full Text PDFJ Am Coll Cardiol
October 2024
Prolocor, Philadelphia, Pennsylvania, USA.
Background: A previous single-center study of patients with myocardial infarction (MI) showed that platelet FcγRIIa (pFCG) can distinguish patients at higher and lower risk of subsequent MI, stroke, and death.
Objectives: The authors performed an 800-patient 25-center study to validate the prognostic implications of pFCG.
Methods: Patients with type 1 MI (ST-segment elevation and non-ST-segment elevation) were enrolled in a prospective noninterventional trial during their index hospitalization.
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