Wave Reflections in a Circular Ripple Tank

2021 ◽  
Vol 59 (7) ◽  
pp. 556-559
Author(s):  
Gisselle Dieguez ◽  
Jonathan Karpenkopf ◽  
Aaron Labrador ◽  
Ludmila Gimenez ◽  
Julian Guerra ◽  
...  
Keyword(s):  
Wave Reflections

scholarly journals Impact of intragrain spin wave reflections on nanocontact spin torque oscillators

2021 ◽  
Vol 103 (21) ◽  
Author(s):  
Anders J. Eklund ◽  
Mykola Dvornik ◽  
Fatjon Qejvanaj ◽  
Sheng Jiang ◽  
Sunjae Chung ◽  
...  
Keyword(s):  
Spin Wave ◽  
Spin Torque ◽  
Wave Reflections ◽  
Spin Torque Oscillators

Moderately increased alcohol consumption is associated with higher pressure wave reflections and blood pressure in men

2020 ◽  
Author(s):  
Eirini D. Basdeki ◽  
Christiana Tsirimiagkou ◽  
Antonios Argyris ◽  
George Moschonis ◽  
Petros Sfikakis ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Alcohol Consumption ◽  
Pressure Wave ◽  
Wave Reflections

Characterization and clinical implications of peripheral arterial involvement in transthyretin cardiac amyloidosis cardiomyopathy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Stamatelopoulos ◽  
D Delialis ◽  
D Bampatsias ◽  
M.E Tselegkidi ◽  
I Petropoulos ◽  
...  
Keyword(s):  
Risk Factors ◽  
Clinical Significance ◽  
Vascular Involvement ◽  
Control Group ◽  
Peripheral Vascular ◽  
Cvd Risk Factors ◽  
Wave Reflections ◽  
Cvd Risk ◽  
Arterial Involvement ◽  
Peripheral Arterial

Abstract Background The sporadic form of transthyretin amyloidosis cardiomyopathy (ATTR-CM) is underdiagnosed but its prevalence is increasing due to the aging population. Given the poor prognosis of ATTR-CM understanding the underlying pathophysiologic mechanisms of the disease is imperative in order to improve strategies for early diagnosis and risk stratification and to develop new effective therapeutic options. ATTR-CM is associated with hypotension and there is preliminary experimental evidence of vascular involvement but its presence and clinical significance remains unknown. Purpose To characterize peripheral arterial involvement and explore its clinical role in ATTR-CM. Methods We consecutively recruited 28 previously untreated patients with newly diagnosed ATTR-CM and 34 elderly controls >70 years old, without ATTR-CM or heart failure. In both groups, flow-mediated dilatation (FMD) and intima-media thickness (IMT) in the carotid arteries were measured by high-resolution ultrasonography as markers of peripheral vascular reactivity and of subclinical atherosclerosis, respectively. Carotid-femoral pulse wave velocity (PWV) was measured as a marker of arterial stiffness. Aortic blood pressure (BP) and augmentation index (AI) using applanation tonometry were measured as markers of arterial wave reflections, peripheral arterial resistance and central hemodynamics. Echocardiography was performed in all ATTR patients. All cardiovascular (CV) measurements were performed before administration of any ATTR-specific therapy. Results ATTR patients were older and had lower prevalence of hypertension and male gender (p<0.05 for all) than the control group. Aortic and peripheral BP (p=0.016–0.088) and AI (p=0.003) were lower in ATTR patients. IMT in the common (cc) and internal carotid (ic) as well as in the carotid bulb (cb) were significantly higher in ATTR patients (p=0.001–0.042). After multivariable adjustment for traditional CV disease (CVD) risk factors, the ATTR group was independently associated with AI and IMT in cc, cb and ic (p<0.05 for all). In a subgroup of subjects with similar age between groups (n=13 and n=33 and 74.5±2.9 vs. 75.6±3.6 years, for ATTR vs. controls, respectively) differences in AI and cbIMT remained significant. Interestingly, AI was strongly and inversely associated with interventricular wall thickness (IVwt) in ATTR patients (spearman rho=−0.651, p=0.001). After adjustment for traditional CVD risk factors this association remained significant. Conclusion ATTR-CM is associated with lower aortic wave reflections, which correlate with more advanced structural cardiac disease, as assessed by IVwt. Further, ATTR-CM patients present accelerated subclinical carotid atherosclerosis as compared to elderly control subjects. These findings suggest that in ATTR-CM there is disease-specific peripheral vascular involvement in parallel to cardiac involvement. The clinical significance of these findings merits further investigation. Funding Acknowledgement Type of funding source: None

1.3 CENTRAL PRESSURES AND WAVE REFLECTIONS ARE INDEPENDENTLY ASSOCIATED WITH MAJOR ADVERSE CARDIOVASCULAR EVENTS IN MEN WITH ERECTILE DYSFUNCTION

2016 ◽  
Vol 16 (C) ◽  
pp. 48
Author(s):  
Nikitas Skliros ◽  
Nikolaos Ioakeimidis ◽  
Charalambos Vlachopoulos ◽  
Dimitrios Terentes-Printzios ◽  
Athanasios Aggelis ◽  
...  
Keyword(s):  
Erectile Dysfunction ◽  
Cardiovascular Events ◽  
Major Adverse Cardiovascular Events ◽  
Wave Reflections

[PP.09.23] SMOKING ACCELERATES WAVE REFLECTIONS IN PREHYPERTENSIVE INDIVIDUALS

2017 ◽  
Vol 35 ◽  
pp. e155
Author(s):  
P. Pietri ◽  
C. Vlachopoulos ◽  
D. Terentes-Printzios ◽  
C. Georgakopoulos ◽  
C. Stefanadis
Keyword(s):  
Wave Reflections

Wave reflections and left ventricular mass in aortic stenosis

2014 ◽  
Vol 8 (4) ◽  
pp. e43
Author(s):  
Prasad Konda ◽  
Payman Zamani ◽  
Scott Akers ◽  
Prithvi Shiva Kumar ◽  
Shivapriya Peddireddy ◽  
...  
Keyword(s):  
Aortic Stenosis ◽  
Left Ventricular Mass ◽  
Left Ventricular ◽  
Wave Reflections ◽  
Ventricular Mass

Pulse Wave Reflections at the Aorto-Iliac Junction

Angiology ◽  
1985 ◽  
Vol 36 (8) ◽  
pp. 516-521 ◽  
Author(s):  
John K.-J. Li
Keyword(s):  
Pulse Wave ◽  
Wave Reflections

Reducing Undesired Wave Reflection at Domain Boundaries in 3D Finite Volume-Based Flow Simulations via Forcing Zones

2020 ◽  
Vol 64 (01) ◽  
pp. 23-47
Author(s):  
Robinson Peric ◽  
Moustafa Abdel-Maksoud
Keyword(s):  
Finite Volume ◽  
Wave Reflection ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Special Focus ◽  
Computational Domain ◽  
Wave Reflections ◽  
Flow Simulations ◽  
Large Eddy ◽  
Domain Boundaries

This article reviews different types of forcing zones (sponge layers, damping zones, relaxation zones, etc.) as used in finite volume-based flow simulations to reduce undesired wave reflections at domain boundaries, with special focus on the case of strongly reflecting bodies subjected to long-crested incidence waves. Limitations and possible sources of errors are discussed. A novel forcing-zone arrangement is presented and validated via three-dimensional (3D) flow simulations. Furthermore, a recently published theory for predicting the forcing-zone behavior was investigated with regard to its relevance for practical 3D hydrodynamics problems. It was found that the theory can be used to optimally tune the case-dependent parameters of the forcing zones before running the simulations. 1. Introduction Wave reflections at the boundaries of the computational domain can cause significant errors in flow simulations, and must therefore be reduced. In contrast to boundary element codes, where much progress in this respect has been made decades ago (see e.g., Clement 1996; Grilli &Horillo 1997), for finite volume-based flow solvers, there are many unresolved questions, especially:How to reliably reduce reflections and disturbances from the domain boundaries?How to predict the amount of undesired wave reflection before running the simulation? This work aims to provide further insight to these questions for flow simulations based on Navier-Stokes-type equations (Reynolds-averaged Navier-Stokes, Euler equations, Large Eddy Simulations, etc.), when using forcing zones to reduce undesired reflections. The term "forcing zones" is used here to describe approaches that gradually force the solution in the vicinity of the boundary towards some reference solution, as described in Section 2; some examples are absorbing layers, sponge layers, damping zones, relaxation zones, or the Euler overlay method (Mayer et al. 1998; Park et al. 1999; Chen et al. 2006; Choi &Yoon 2009; Jacobsen et al. 2012; Kimet al. 2012; Schmitt & Elsaesser 2015; Perić & Abdel-Maksoud 2016a; Vukčević et al. 2016).

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