The triggering of avalanches is investigated using discrete element simulations for a process of random extraction of spheres. A monolayer, formed by identical spheres in a hexagonal configuration, is placed on a tilted plane surrounded by a small fence that sustains the spheres, mimicking the disposal of fruits in the market. Then, a random continuous extraction process of spheres is imposed until the collapse. For this simple numerical experiment, a phase diagram was obtained to visualize the occurrence of avalanches triggered by vacancies as a function of the tilting angle, system size, and friction coefficient. More importantly, a subzone was found where we can predict the critical number of extractions until the avalanche takes place. The prediction is made from an evolution model of the average coordination number based on statistical considerations. The theoretical prediction also gives a constant critical void fraction of spheres, which implies the system collapses at a critical packing fraction.
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http://dx.doi.org/10.1103/PhysRevE.108.064904 | DOI Listing |
Food Chem
December 2024
Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, People's Republic of China; Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, People's Republic of China. Electronic address:
A novel biomimetic molecular imprinted polymer chip with fluorescence (FL) and structural (STR) states, inspired by color patterns of chameleon skin, is fabricated for detecting diethylstilbestrol (DES). The chip features a regularly structured, non-closed-packed (NCP) colloidal photonic crystal (CPC) lattice made monodisperse MIP spheres containing fluorescence poly ionic liquid (FPIL) pigments. The FL color originates from FPIL pigments and is further enhanced by the Purcell effect, while the STR color results from the periodic arrangement of the NCP CPC structure.
View Article and Find Full Text PDFMed Phys
December 2024
Department of Physics, Lakehead University, Thunder Bay, Ontario, Canada.
Background: This study investigates a multi-angle acquisition method aimed at improving image quality in organ-targeted PET detectors with planar detector heads. Organ-targeted PET technologies have emerged to address limitations of conventional whole-body PET/CT systems, such as restricted axial field-of-view (AFOV), limited spatial resolution, and high radiation exposure associated with PET procedures. The AFOV in organ-targeted PET can be adjusted to the organ of interest, minimizing unwanted signals from other parts of the body, thus improving signal collection efficiency and reducing the dose of administered radiotracer.
View Article and Find Full Text PDFInorg Chem
December 2024
Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.
The nonheme iron(II) complexes containing a fluoride anion, Fe(BNPAO)(F) () and [Fe(BNPAOH)(F)(THF)](BF) (), were synthesized and structurally characterized. Addition of dioxygen to either or led to the formation of a fluoride-bridged, dinuclear iron(III) complex [Fe(BNPAO)(F)(μ-F)] (), which was characterized by single-crystal X-ray diffraction, H NMR, and elemental analysis. An iron(II)(iodide) complex, Fe(BNPAO)(I) (), was prepared and reacted with O to give the mononuclear complex -Fe(BNPAO)(OH)(I) ().
View Article and Find Full Text PDFPLoS One
December 2024
Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy.
How to distribute a set of points uniformly on a spherical surface is a longstanding problem that still lacks a definite answer. In this work, we introduce a physical measure of uniformity based on the distribution of distances between points, as an alternative to commonly adopted measures based on interaction potentials. We then use this new measure of uniformity to characterize several algorithms available in the literature.
View Article and Find Full Text PDFPLoS One
December 2024
Department of Sociology of Culture, Religion and Social Participation, John Paul II Catholic University of Lublin, Lublin, Poland.
Introduction: The article is devoted to the sociological exploration of the social phenomenon that Nordic Walking has become in Europe and worldwide over the recent decades.
Aim: It is based on the results of original international sociological research study on the issue of sociodemographic profiles of Nordic Walkers in the context of the values associated with this sports activity.
Methods: A cross-sectional quantitative study with convenience sampling study was performed among 416 Poles, 132 Europeans from 11 countries (Germany, the UK, Spain, France, Italy, Portugal, Ireland, Denmark, Austria, Sweden, and Norway), and 212 participants from 5 non-European countries (the USA, Canada, Australia, New Zealand, and Japan).
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