We study, from first principles, the pressure exerted by an active fluid of spherical particles on general boundaries in two dimensions. We show that, despite the nonuniform pressure along curved walls, an equation of state is recovered upon a proper spatial averaging. This holds even in the presence of pairwise interactions between particles or when asymmetric walls induce ratchet currents, which are accompanied by spontaneous shear stresses on the walls. For flexible obstacles, the pressure inhomogeneities lead to a modulational instability as well as to the spontaneous motion of short semiflexible filaments. Finally, we relate the force exerted on objects immersed in active baths to the particle flux they generate around them.
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http://dx.doi.org/10.1103/PhysRevLett.117.098001 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong 999077, P. R. China.
Fe-N-C materials are emerging catalysts for replacing precious platinum in the oxygen reduction reaction (ORR) for renewable energy conversion. However, their potential is hindered by sluggish ORR kinetics, leading to a high overpotential and impeding efficient energy conversion. Using iron phthalocyanine (FePc) as a model catalyst, we elucidate how the local strain can enhance the ORR performance of Fe-N-Cs.
View Article and Find Full Text PDFMycoKeys
December 2024
Yunnan Provincial Key Laboratory for Conservation and Utilization of In-forest Resource, the Key Laboratory of Forest Resources Conservation and Utilization in the Southwest Mountains of China Ministry of Education, Southwest Forestry University, Kunming 650224, China Southwest Forestry University Kunming China.
Three new fungal species, , and , are proposed based on a combination of the morphological features and molecular evidence. The taxon is characterized by the coriaceous basidiomata with a cream surface, cylindrical basidia, straight, 4-celled, subglobose or ovoid probasidia and thin-walled, narrowly cylindrical basidiospores with septa, measuring as 7-9 × 3.5-4.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
The thin-walled hyperbolic structures made from titanium alloy primarily encompass two typical forms: hyperbolic convex and hyperbolic concave (saddle). This paper addresses the technical challenges associated with the forming processes that frequently result in ripples or wrinkles in these configurations. Specifically, it investigates precision control techniques for the hot forming process of thin-walled hyperbolic skins from TC4 titanium alloy.
View Article and Find Full Text PDFInt J Womens Health
December 2024
Sydney Women's Endosurgery Centre (SWEC), St George Hospital, Sydney, NSW, Australia.
Objective: We aimed to explore the abnormal pathology findings in appendix specimens removed based on intraoperative abnormal appearance during elective surgery for benign gynaecological conditions by a minimally invasive gynaecologist, as well as the associated complication rate.
Materials And Methods: This retrospective cohort study was conducted in a tertiary referral surgical centre for benign gynaecological conditions between the years 2004-2023. It included patients who underwent appendicectomy by a trained minimally invasive gynaecologist based on observations during surgery for benign gynaecological conditions.
Plant Dis
December 2024
Korea University, Environmental Science & Ecological Engineering, Seoul, Seoul, Korea (the Republic of), 02841;
Cerastium glomeratum Thuill., known as sticky mouse-ear chickweed, is native to Europe and has become naturalized in the wild on most continents. After its accidental introduction to Korea around the 1980s, it quickly became one of the dominant invasive weeds on the Korean peninsula and is now considered a significant threat to the Korean agroecosystem (Park et al.
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