We investigate the possibility of having horizons inside various classical field configurations. Using the implicit function theorem, we show that models satisfying a certain set of criteria allow for (at least) small horizons within extended matter fields. Gauge and global monopoles and Skyrmions satisfy these criteria. Q-balls and Boson stars are examples which do not and can be shown not to ...

A general analysis for characterizing and classifying ‘isolated horizons’ is presented in terms of null tetrads and spin coefficients. The freely specifiable spin coefficients corresponding to isolated horizons are identified and specific symmetry classes are enumerated. For isolated horizons admitting at least one spatial isometry, a standard set of spherical coordinates are introduced and ass...

For predictive control in industry often very long horizons for control error and manipulated signal are used because of the slow processes which take place in the petrochemical industry. In order to reduce the computational effort some commercial predictive control program packages offer the ability to reduce the number of points in both horizons but do not recommend how to select the points w...

physical and chemical properties of  crude oil, including viscosity and api gravity, are commonly inherited  from the  early organic matter, environmental conditions in which they were deposited and depth of burial of the source beds. api gravity increases in deeper burial due to higher thermal maturation of organic matter in the source rocks and consequently, generation of lighter saturated hy...

Phytoplankton size and relations between phytoplankton and microzooplankton (ciliates and heterotrophic dinoflagellates) biomass are analysed in 12 globally distributed areas. In view of the results, a hypothesis is posed where blooming species are those able to escape control by microzooplankton through a combination of predation avoidance mechanisms (e.g. larger size, colonies, spines, and to...

The Serra do Mar complex in the southeastern Brazil is subject to frequent landslides especially on the Atlantic coast. The three dimensional organisation of the soil was studied in a 56 ha representative catchment. Upslope in situ soil material has developed from the parent rock, and downslope the soil has resulted from landslide processes. The soil mantle upslope is mainly characterised by sl...