The effects of some crystallisation conditions on the formation of orthorhombic paracetamol from ethanolic solution are examined when seeding technique is applied under fixed agitation (700 rpm) and harvesting time (30 min). Three equally spaced levels were used for initial concentration, C(I) (30 +/- 4% w/v), for seeding temperature, T(S) (7 +/- 7 degrees C) and for cooling temperature, T(C) (...

Flavodoxins are small flavoproteins (M, 15000-22000), that have been found in several strains of bacteria and algae [ I ] The protein contains one molecule of non-covalently bound FMN and hnctions biochemically as a one-electron carrier between the semiquinone and hlly reduced forms. Under iron-deficient conditions the protein is produced by Megasphaera elsdenii to replace the iron-sulphur prot...

The paper is an investigation into the relation between use-oriented design and object-oriented methods. Based on the notions of historical crystallisation of praxis into artefacts, the concept of secondary artefacts, and the notion of boundary objects, it is argued that object-oriented descriptions should be understood as transformations of artefacts from the considered praxis rather than mode...

In this note we discuss the structure of systems of coupled cells (which we view as systems of ordinary differential equations) where symmetries of the system are obtained through the group G of global permutations of the cells and the group L of local internal symmetries of the dynamics in each cell. We show that even when the cells are assumed to be identical with identical coupling, the way ...

The good sheik evidently holds the Copernican theory to be a "mere theory," not a "fact." In this he is technically correct. A theory can be verified by a mass of facts, but it becomes a proven theory, not a fact. The sheik was perhaps unaware that the Space Age had begun before he asked the king to suppress the Copernican heresy. The sphericity of the earth has been seen by astronauts, and eve...