7 research outputs found
Lagrangian coherent structures and entrainment near the turbulent/non-Turbulent interface of a gravity current
Universal alignment in turbulent pair dispersion
Countless processes in nature and industry, from rain droplet nucleation to
plankton interaction in the ocean, are intimately related to turbulent
fluctuations of local concentrations of advected matter. These fluctuations can
be described by considering the change of the separation between particle
pairs, known as pair dispersion, which is believed to obey a cubic in time
growth according to Richardson's theory. Our work reveals a universal,
scale-invariant alignment between the relative velocity and position vectors of
dispersing particles at a mean angle that we show to be a universal constant of
turbulence. We connect the value of this mean angle to Richardson's traditional
theory and find agreement with data from a numerical simulation and a
laboratory experiment. While the Richardson's cubic regime has been observed
for small initial particle separations only, the constancy of the mean angle
manifests throughout the entire inertial range of turbulence. Thus, our work
reveals the universal nature of turbulent pair dispersion through a geometrical
paradigm whose validity goes beyond the classical theory, and provides a novel
framework for understanding and modeling transport and mixing processes.Comment: 20 pages, three figure
Connecting the time evolution of the turbulence interface to coherent structures - Corrigendum
Objective Coherent Structures Near the Turbulent/Non-Turbulent Interface in a Stably Stratified Turbulent Flow
Acute Aortic Syndromes from Diagnosis to Treatment—A Comprehensive Review
This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an “aorta code”. Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in “aortic centres” improves long-term outcomes and decreases mortality rates.ISSN:2077-038
Lagrangian coherent structures and entrainment near the turbulent/non-turbulent interface of a gravity current
Acute Aortic Syndromes from Diagnosis to Treatment—A Comprehensive Review
This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an “aorta code”. Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in “aortic centres” improves long-term outcomes and decreases mortality rates