In this paper we look at the difficulty of fixing solutions of classic network problems. We study local changes in graphs (edge resp. node insertion resp. deletion), and network problems (e.g. maximal independent set, minimum vertex cover, spanning trees, shortest paths). A change/problem combination is locally fixable if an existing solution of a problem can be fixed in constant time in case o...

Over the years, many ideas have been handed down from one technologist to another about what to do and what not to do when fixing cells and tissues. This set of experiments takes into account certain conditions involving the age of the prepared primary fixative, length of time in primary fixative, length of time en bloc stain is on tissue cultured cells and the effect of washing the cells befor...

The matrix elements of the quadrupole collective variables, emerging from collective nuclear models, are calculated in the natural Cartan-Weyl basis of O(5) which is a subgroup of a covering SU (1, 1) × O(5) structure. Making use of an intermediate set method, explicit expressions of the matrix elements are obtained in a pure algebraic way, fixing the γ-rotational structure of collective quadru...

Gas-lift is one of the most used artificial lift methods worldwide. In Brazil it responds for more than 70% of the total oil production. Gas-lift wells are known to present oscillatory behavior associated with phenomena like heading and density wave. This work presents an innovative way to control these oscillations. The approach adopted controls the well dynamics without fixing any operational...