Significance of Pulmonary Elastic and Viscous
نویسندگان
چکیده
The mechanical properties of the lungs were measured in the sitting and supine positions in 5 normal subjects and in 5 patients with orthopnea due to congestive heart failure. The patients had higher elastic and viscous resistances in the sitting position. Recumbency increased both resistances in both groups but there was a disproportionate increase in the viscous resistance of the patients. This increase was most marked in late expiration and early inspiration. The significance of these findings to orthopnea is discussed.
منابع مشابه
مدل سازی عددی برخورد سیال لزج با صفحه الاستیک شناور در یک حوضچه محدود
The estimation of wave loads on very large flouting structure is usually done by an empirical or a computational approach. The computational approach usually assumes two types. Some use the Laplace equation or potential flow and some take the Navier-Stokes equation or viscous flow analysis. In this study, the interaction between wave and elastic plate is investigated by using viscous flow assum...
متن کاملElectro-Thermo-Dynamic Buckling of Embedded DWBNNT Conveying Viscous Fluid
In this paper, the nonlinear dynamic buckling of double-walled boron-nitride nanotube (DWBNNT) conveying viscous fluid is investigated based on Eringen's theory. BNNT is modeled as an Euler-Bernoulli beam and is subjected to combine mechanical, electrical and thermal loading. The effect of viscosity on fluid-BNNT interaction is considered based on Navier-Stokes relation. The van der Waals (vdW)...
متن کاملThe Measurement of Rigidity in Elbow Joint: An Objective Method for the Evaluation of Parkinson's disease
Introduction: One of the most common syndromes in Parkinson's disease (PD) is rigidity. Currently, an index is used to evaluate the level of PD by the clinical measurement of rigidity in the upper extremity. The index uses a subjective method called Unified Parkinson's Disease Rating System (UPDRS). The subjective nature of this method makes the influence of physician in the measurement of rigi...
متن کاملViscous Fluid Flow-Induced Nonlocal Nonlinear Vibration of Embedded DWBNNTs
In this article, electro-thermo nonlocal nonlinear vibration and instability of viscous-fluid-conveying double–walled boron nitride nanotubes (DWBNNTs) embedded on Pasternak foundation are investigated. The DWBNNT is simulated as a Timoshenko beam (TB) which includes rotary inertia and transverse shear deformation in the formulation. Considering electro-mechanical coupling, the nonlinear govern...
متن کاملNonlinear Instability of Coupled CNTs Conveying Viscous Fluid
In the present study, nonlinear vibration of coupled carbon nanotubes (CNTs) in presence of surface effect is investigated based on nonlocal Euler-Bernoulli beam (EBB) theory. CNTs are embedded in a visco-elastic medium and placed in the uniform longitudinal magnetic field. Using von Kármán geometric nonlinearity and Hamilton’s principle, the nonlinear higher order governing equations are deriv...
متن کامل