Dynamic Equilibrium Configurations of Multibody Systems

2014 ◽  
Vol 619 ◽  
pp. 8-12
Author(s):  
Ju Seok Kang
Keyword(s):  
Iteration Method ◽  
Multibody Systems ◽  
Equilibrium Configuration ◽  
Dynamic Equilibrium ◽  
Mechanical Systems ◽  
Railway Vehicle ◽  
Algebraic Form ◽  
Constrained Mechanical Systems ◽  
Speed Governor ◽  
Equilibrium Configurations

It is difficult to calculate dynamic equilibrium configuration in the mechanical systems, especially with the constraint conditions. In this paper, a method to calculate the dynamic equilibrium positions in the constrained mechanical systems is proposed. The accelerations of independent coordinates are derived in the algebraic form so that the numerical solution is easily obtained by the iteration method. The proposed method has been applied to calculate the dynamic equilibrium configuration for speed governor and the wheelset of railway vehicle.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Platelet Adhesion to Subendothelium - Effect of Shear Rate, Hematocrit and Platelet Count on the Dynamic Equilibrium Between Platelets Adhering to and Detaching from the Surface

1985 ◽  
Vol 54 (04) ◽  
pp. 857-861 ◽  
Author(s):  
Andrea Remuzzi ◽  
Lucia Raffaella Languino ◽  
Vincenzo Costantini ◽  
Vincenzo Guardabasso ◽  
Giovanni de Gartano ◽  
...  
Keyword(s):  
Platelet Adhesion ◽  
Initial Rate ◽  
Dynamic Equilibrium ◽  
Dynamic Condition ◽  
Platelet Reactivity ◽  
Experimental Conditions ◽  
Platelet Suspension ◽  
Shear Rates ◽  
Platelet Concentration ◽  
Adhesion Rate

SummaryThe adherence of human 3H-adenine-labeled platelets to rat subendothelium was quantitated using a rotating probe device. Platelet adhesion increased in relation to the rotation time, reaching a plateau value in about 4-6 min without any further increase. A non-linear fitting analysis of experimental data allowed calculations of initial rate and plateau value of platelet adhesion. Increasing the shear rates (from 35 to 150 sec-1) or the hematocrit (from 10% to 40%), both the adhesion rate and the plateau value were increased. When different platelet concentrations were used the adhesion rate and the plateau calculated increased with platelet concentration. Different plateau values were obtained in the experimental conditions considered. This suggests that the plateau was not reached for the complete occupation of the subendothelial surface by the adherent platelets. Experiments using two different vessels rotated in the same platelet suspension or, viceversa, the same vessel rotated successively in two fresh platelet suspensions, showed that the plateau was not determined by reduced platelet reactivity. Rotating the same vessel first in radiolabeled platelets, until the plateau was reached, and secondly in non labeled platelets, or viceversa, showed that the plateau was indeed a dynamic condition where the number of platelets adhering and detaching reached equilibrium. These observations suggest that the platelet adhesion to subendothelium is the final equilibrium of two platelet fluxes, one adhering to the surface and another detaching from the surface.

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