18 research outputs found
A Dataflow Graphical Language for Database Applications
In this paper we discuss a graphical language for information retrieval and processing. A lot of recent activity has occurred in the area of improving access to database systems. However, current results are restricted to simple interfacing of database systems. We propose a graphical language for specifying complex applications
Adjoint regular rings
Let R be a ring. The circle operation is the operation
aâb=a+bâab, for all a,bâR. This operation
gives rise to a semigroup called the adjoint semigroup
or circle semigroup of R. We investigate rings in
which the adjoint semigroup is regular. Examples are given which
illustrate and delimit the theory developed
Maximal ideals in near-rings and semigroups
This paper gives conditions that guarantee that a
near-ring or a semi-group has maximal right, left, or two-sided ideals.
Stronger results are obtained for those semigroups
which are adjoint semigroups
of rings. Examples are given which illustrate and delimit the theory developed.
Mathematics Subject
Classification (2000):
16Y30, 20M12, 16N20
Key words: Near-ring; semigroup;
ideal; maximal; idempotent
Quaestiones
Mathematicae 25 (2002), 259-26
Inorganic Photovoltaics - Planar and Nanostructured Devices
Since its invention in the 1950s, semiconductor solar cell technology has evolved in great leaps and bounds. Solar power is now being considered as a serious leading contender for replacing fossil fuel based power generation. This article reviews the evolution and current state, and potential areas of near future research focus, of leading inorganic materials based solar cells, including bulk crystalline, amorphous thin-films, and nanomaterials based solar cells. Bulk crystalline silicon solar cells continue to dominate the solar power market, and continued efforts at device fabrication improvements, and device topology advancements are discussed. III-V compound semiconductor materials on c-Si for solar power generation are also reviewed. Developments in thin-film based solar cells are reviewed, with a focus on amorphous silicon, copper zinc tin sulfide, cadmium telluride, as well as nanostructured Cadmium telluride. Recent developments in the use of nano-materials for solar power generation, including silicon and gallium arsenide nanowires, are also reviewed