The cracking of rock mass under compression is the main factor causing structural failure. Therefore, it is very crucial to establish a rock damage evolution model to investigate the crack development process and reveal the failure and instability mechanism of rock under load. In this study, four different strength types of rock samples from hard to weak were selected, and the Voronoi method was used to perform and analyze uniaxial compression tests and the fracture process. The change characteristics of the number, angle, and length of cracks in the process of rock failure and instability were obtained. Three laws of crack development, damage evolution, and energy evolution were analyzed. The main conclusions are as follows. (1) The rock's initial damage is mainly caused by tensile cracks, and the rapid growth of shear cracks after exceeding the damage threshold indicates that the rock is about to be a failure. The development of micro-cracks is mainly concentrated on the diagonal of the rock sample and gradually expands to the middle along the two ends of the diagonal. (2) The identification point of failure precursor information in Acoustic Emission (AE) can effectively provide a safety warning for the development of rock fracture. (3) The uniaxial compression damage constitutive equation of the rock sample with the crack length as the parameter is established, which can better reflect the damage evolution characteristics of the rock sample. (4) Tensile crack requires low energy consumption and energy dispersion is not concentrated. The damage is not apparent. Shear cracks are concentrated and consume a large amount of energy, resulting in strong damage and making it easy to form macro-cracks.
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http://dx.doi.org/10.3390/ma14092108 | DOI Listing |
Mol Plant
January 2025
State Key Laboratory of Wheat Improvement, School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China; Beijing Life Science Academy, Beijing 102299, China. Electronic address:
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View Article and Find Full Text PDFInt J Food Microbiol
January 2025
School of Life Science and Technology, Shandong Second Medical University, Weifang, Shandong, China. Electronic address:
Escherichia coli O157:H7 has caused many foodborne disease outbreaks and resulted in unimaginable economic losses. With the evolution of food consumption, people prefer natural preservatives. In this study, the natural agent harmane exhibited potential activity against E.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Institute for Polymers Composites and Biomaterials, Italian National Research Council, Piazzale Enrico Fermi, 80055 Portici, NA, Italy.
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View Article and Find Full Text PDFPathogens
January 2025
Department of Pharmacology and Toxicology, Faculty of Biosciences, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan.
(1) Background: Surra is a debilitating disease of wild and domestic animals caused by (), resulting in significant mortality and production losses in the affected animals. This study is the first to assess the genetic relationships of in naturally affected buffaloes from Multan district, Pakistan, using ITS-1 primers and evaluating the effects of parasitemia and oxidative stress on DNA damage and hematobiochemical changes in infected buffaloes. (2) Methods: Blood samples were collected from 167 buffaloes using a multi-stage cluster sampling strategy, and trypomastigote identification was performed through microscopy and PCR targeting RoTat 1.
View Article and Find Full Text PDFPathogens
January 2025
Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Noria Alta s/n, Guanajuato 36050, Mexico.
The path to survival for pathogenic organisms is not straightforward. Pathogens require a set of enzymes for tissue damage generation and to obtain nourishment, as well as a toolbox full of alternatives to bypass host defense mechanisms. Our group has shown that the parasitic protist encodes for 14 sphingomyelinases (SMases); one of them (acid sphingomyelinase 6, aSMase6) is involved in repairing membrane damage and exhibits hemolytic activity.
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