Stability of the quasi-static equilibrium state of a viscous layer of an inclined plane

1967 ◽  
Vol 2 (3) ◽  
pp. 111-112
Author(s):  
A. N. Bozhinskii
Keyword(s):  
Equilibrium State ◽  
Static Equilibrium ◽  
Viscous Layer ◽  
Inclined Plane ◽  
Static Equilibrium State

scholarly journals Geometrical Nonlinear Aeroelastic Stability Analysis of a Composite High-Aspect-Ratio Wing

2008 ◽  
Vol 15 (3-4) ◽  
pp. 325-333 ◽  
Author(s):  
Chang Chuan Xie ◽  
Jia Zhen Leng ◽  
Chao Yang
Keyword(s):  
Stability Analysis ◽  
Aspect Ratio ◽  
Equilibrium State ◽  
High Aspect Ratio ◽  
Unsteady Aerodynamics ◽  
Static Equilibrium ◽  
Beam Model ◽  
Aeroelastic Stability ◽  
Nonlinear Flutter ◽  
Static Equilibrium State

A composite high-aspect-ratio wing of a high-altitude long-endurance (HALE) aircraft was modeled with FEM by MSC/NASTRAN, and the nonlinear static equilibrium state is calculated under design load with follower force effect, but without load redistribution. Assuming the little vibration amplitude of the wing around the static equilibrium state, the system is linearized and the natural frequencies and mode shapes of the deformed structure are obtained. Planar doublet lattice method is used to calculate unsteady aerodynamics in frequency domain ignoring the bending effect of the deflected wing. And then, the aeroelastic stability analysis of the system under a given load condition is successively carried out. Comparing with the linear results, the nonlinear displacement of the wing tip is higher. The results indicate that the critical nonlinear flutter is of the flap/chordwise bending type because of the chordwise bending having quite a large torsion component, with low critical speed and slowly growing damping, which dose not appear in the linear analysis. Furthermore, it is shown that the variation of the nonlinear flutter speed depends on the scale of the load and on the chordwise bending frequency. The research work indicates that, for the very flexible HALE aircraft, the nonlinear aeroelastic stability is very important, and should be considered in the design progress. Using present FEM software as the structure solver (e.g. MSC/NASTRAN), and the unsteady aerodynamic code, the nonlinear aeroelastic stability margin of a complex system other than a simple beam model can be determined.

scholarly journals SOLITON NATURE OF EQUILIBRIUM STATE OF TWO CHARGED MASSES IN GENERAL RELATIVITY

2012 ◽  
Vol 12 ◽  
pp. 10-18 ◽  
Author(s):  
G. A. ALEKSEEV ◽  
V. A. BELINSKI
Keyword(s):  
General Relativity ◽  
Equilibrium State ◽  
Inverse Scattering ◽  
Integral Equation Method ◽  
Inverse Scattering Method ◽  
Scattering Method ◽  
Naked Singularities ◽  
Additional Support ◽  
Static Equilibrium State ◽  
Charged Masses

New derivation of static equilibrium state for two charged masses in General Relativity is given in the framework of the Inverse Scattering Method in contradistinction to our previous derivation of this solution by the Integral Equation Method. This shows that such solution is of solitonic character and represents the particular case of more general (12-parametric) stationary axisymmetric electrovacuum two-soliton solution for two rotating charged objects obtained by one of the authors in 1986. This result gives an additional support to our comprehension that the appropriate analytical continuations of solitonic solutions in the space of their parameters are always possible and that applicability of the Inverse Scattering Method in presence of electromagnetic field is not restricted only to the cases with naked singularities. The paper represents the shortened version of the plenary talk given at the Second Galileo - Xu Guangqi meeting (July 12-18, 2010, Ventimiglia, Italy).

A Hitherto Undescribed Naturally Occurring Plasma Antagonist of Activated Factor X Inhibitor (Antithrombin III)

1979 ◽  
Author(s):  
E. T. Yin ◽  
W. J. Salsgiver ◽  
O. Tangen
Keyword(s):  
Equilibrium State ◽  
Human Plasma ◽  
Antithrombin Iii ◽  
Circumstantial Evidence ◽  
Incubation Mixture ◽  
Factor X ◽  
Normal Human Plasma ◽  
Plasma Component ◽  
Naturally Occurring ◽  
Normal Human

Circumstantial evidence suggested that normal human plasma contained a substance regulating the neutralization of F.Xa by F.Xa inhibitor(XaI), (Yin et.al.,Adv.Exper. Med. & Biol., 52 : 239, 1975, Plenum Press, N.Y.).This plasma component has now been isolated and partially purified in our laboratory, and tentatively designated as “Anti-XaI”.In experiments employing purified components, when Anti-XaI was incubated at 37°C with F.Xa, Xal and heparin for two minutes at pH7.5, the amount of F.Xa inhibited was inversely proportional to the Anti-XaI concentration. But, when the F.Xa was replaced by thrombin in the incubation mixture, the neutralization of thrombin clotting activity was undisturbed.Anti-XaI was found to be neither PF3 nor PF4.These and other data strongly suggest that the “Antithrombin III pathway” is more complex than currently believed to be. In circulating blood an equilibrium state must exist between Anti-XaI and XaI.Under certain conditions when the Anti-XaI activity is predominant the rate of F.Xa neutralization bv XaI then becomes slower than the activation of prothrombin to thrombin by F.Xa.

Peculiarities in the Establishment of Equilibrium State in Diluted Aqueous Solutions of Glycerol

2014 ◽  
Vol 59 (7) ◽  
pp. 689-695 ◽  
Author(s):  
Bulavin L.A. Bulavin L.A. ◽  
◽  
V.Ya. Gotsulskiy ◽  
V.E. Chechko ◽  
◽  
...  
Keyword(s):  
Equilibrium State ◽  
Aqueous Solutions
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