Doğuş Cendek 0300601010 10th

Melt Flow Index (Melt Folw Index) (11:10) Melt flow index is measured using the melt indexer accoring to ASTM.The melt indexer uses a very short capillary with L/D=3.818 and a flat entry.Such capillary geometry accentuates the elasticity of melt,and the elasticity significantly influence the melt flow index.Therefore polymers with the same melt flow index (MFI) can have quite different viscosities and elasticities.MFI is measured at a low shear stress corresponding to a low shear rate.Polymers with the same MFI can have different viscosities elasticities at high shear rate,depending on their shear sensitivities. (Chung C.I., Extrusion of Polymers:Theory and Practice, p. 132)

LaSalle's Theorem(10:59 18.04)

The state x=0 stable if one can find differentable positive definite function V(x) such that

Derivative of V(x) < 0

for all trajectories provided that the set of points where Derivative of V(x) = 0

S={x€R^n: Derivative of V(x)=0}

contains no trajectories other than the trivial one x=0

(Preumont A.,Vibration control of active structures,p. 251)

NED (North-East-Down) (11:14 18.04)

The NED frame can be found if the nearest point Q point from the point P is determined on the rotational ellipsoid which will be origin of the Kned frame. Then the tangential plane at the point Q will be determined in which plane the orthonormal coordinate axes: Xned,Yned and Zned points to local north,east and down respectively.Notice that Zned points downwards,inside the rotational ellipsoid.

(Lantos B.,Marton L.,Nonlinear Control of Vecihles and Robots,p. 107)

Pitch Rate Specification (11:25 18.04)

There are number of special cases in pitch rate specification that are worthy of more detailed discussion.The first of these is the gravity turn which is defined by teh specification of an initial flight path angle, and the requirement the angle of attack be maintained at zero throughout the boost.In this way no thrust is wasted in this sense of being applied normal to the flight path.All thrust is used to increase the magnitude of the current velocity is controlled to align the vehicle along the current velocity vector.

(Griffin M.D., French J.R., Space Vehicle Design,p. 228)