On the Straightening Law for Minors of a Matrix

Cyclic orders on the quantum grassmannian

The quantum grassmannian is known to be a graded quantum algebra with a straightening law when the poset of generating quantum minors is endowed with the standard partial ordering. In this paper it is shown that this result remains true when the ordering is subjected to cyclic shifts. The method involves proving that noncommutative dehomogenisation is possible at any consecutive quantum minor. ...

Hilbert functions of ladder determinantal varieties

We consider algebraic varieties de)ned by the vanishing of all minors of a )xed size of a rectangular matrix with indeterminate entries such that the indeterminates in these minors are restricted to lie in a ladder shaped region of the rectangular array. Explicit formulae for the Hilbert function of such varieties are obtained in (i) the rectangular case by Abhyankar (Rend. Sem. Mat. Univers. P...

An Investigation on the Causes of a Rotor Bending and its Thermal Straightening (TECHNICAL NOTE)

Distortion or bend in a turbine rotor (especially HIP rotors) may be caused by a number of factors, either singularly or in combination. In general, the causes of rotor bend can be classified invariably in two categories: Rapidly forming permanent rotor bends and/or Slower forming rotor bends, which could trip the turbines’ emergency stop. One of the major modifying solutions for rapid repairin...

Application of the Hot Spotting Method for the Straightening of a Large Turbine Rotor

Different problems may cause distortion of the rotor, and hence vibration, which is the most severe damage of the turbine rotors. Different techniques have been developed for the straightening of bent rotors. The method for straightening can be selected according to initial information from preliminary inspections and tests such as nondestructive tests, chemical analysis, run out tests and also...

Informed consent to the medical treatment of minors: law and practice.