Among specific topics are locally nilpotent derivations of rings graded by an abelian group, notes on the weak positivity theorems, irrational open surfaces of non-negative logarithmic Kodaira dimension, a variant of Shukurov's criterion of toric surface
, and new examples of cylindrical Fano fourfolds.
Soft HydroCone (Toris K) lens is made of SiH material Silikon-Hydrogel (definitive 74%, Igel 77%) that includes a front toric surface
and has a dynamic stabilization with nasal and temporal bumps.
For a smooth projective toric surface X = [X.sub.[SIGMA]], its second Chern character is calculated as [ch.sub.2](X) = (12 - 3m)/2, where m is the number of 1-dimensional cones in S.
Let X be a smooth projective toric surface. If [ch.sub.2](X) is nef but not ample, then X is isomorphic to a Hirzebruch surface.
The contact lens has a front toric surface
and dynamic (with bumps) stabilization.
For the creation of a toric surface where two radiuses are staggered by 90[degrees], the tool has to make two moves for one rotation.
By means of examples the article shows results of experimental investigations of precision-machined toric surfaces, which were realised in co-operation with Jenoptik Polymer Systems GmbH.
1) consists of tree metallic moulds and two plastic prototypes with toric surfaces (metallic moulds: radiuses R 800 and R 600; plastic moulds: radiuses R 800 and R 100).
The components with toric surfaces were manufactured on the ultra-precision turning lathe Nanoform 350 of the company Precitech (see fig.
These lenses have a toroidal back surface and theoretically a spherical front surface, although in reality, most lenses are manufactured with a compensating front toric surface
. Stabilisation is not necessary with this design of lens, since the lens radii should align with the principal meridians of the cornea.
Since its launch, it has continued to evolve and now offers enhanced, advanced design features, including toric surfaces
and quadrant specific edge lifts.
Aimed at both researchers and graduate students interested in various aspects of combinatorial theories, topics here include combinatories of polytopes, lattice polytopes, triangulations and subdivisions, Cohen-Macaulay cell complexes, monomial ideals, the geometry of toric surfaces
, groupoids in combinatories, Kazhdan-Lusztig combinatories and graph colorings.