Received ; accepted – 2 – ABSTRACT Tunable narrow-band, emission-line surveys have begun to show the ease with which star forming galaxies can be identified in restricted redshift intervals to z ∼ 5 with a 4m class telescope. These surveys have been carried out with imaging systems at the Cassegrain or Nasmyth focus and are therefore restricted to fields smaller than 10 ′. We now show that tuna...

Let [Formula: see text] be a finite group and fixed prime divisor of text]. We prove that if every maximal subgroup is nilpotent, or normal, has text]-order, then (1) solvable; (2) Sylow tower; (3) there exists at most one such neither text]-nilpotent nor text]-closed.

Many advanced techniques have been reported in the literature for difficult Günther Tulip filter removal. This report describes a bidirectional loop-snare technique in the setting of a fibrin scar formation around the filter leg anchors. The bidirectional loop-snare technique allows for maximal axial tension and alignment for stripping fibrin scar from the filter legs, a commonly encountered co...

We study Baire category for downward-closed subsets of 2ω , showing that it behaves better in this context than for general subsets of 2ω . We show that, in the downward-closed context, the ideal of meager sets is prime and b-complete, while the complementary filter is g-complete. We also discuss other cardinal characteristics of this ideal and this filter, and we show that analogous results fo...

We study a family of quintic polynomials discoverd by Emma Lehmer. We show that the roots are fundamental units for the corresponding quintic fields. These fields have large class numbers and several examples are calculated. As a consequence, we show that for the prime p = 641491 the class number of the maximal real subfield of the pth cyclotomic field is divisible by the prime 1566401. In an a...

The properties of deductive systems in Hilbert algebras are treated. If a Hilbert algebra H considered as an ordered set is an upper semilattice then prime deductive systems coincide with meet-irreducible elements of the lattice DedH of all deductive systems on H and every maximal deductive system is prime. Complements and relative complements of DedH are characterized as the so called annihila...

In 1969, Denniston gave a construction of maximal arcs of degree d in Desarguesian projective planes of even order q, for all d dividing q. In 2002 Mathon gave a construction method generalizing the one of Denniston. We will give a new geometric approach to these maximal arcs. This will allow us to count the number of non-isomorphic Mathon maximal arcs of degree 8 in PG(2, 2h), h 6= 7 and prime...

In the paper, we extend the definition of generalized derivations to superalgebras and prove that a generalized superderivation g on a prime superalgebra A is represented as g(x) = ax + d(x) for all x ∈ A, where a is an element of Qmr (the maximal right ring of quotients of A) and d is a superderivation on A. Using the result we study two generalized superderivations when their product is also ...

The Heisenberg double Dq(E2) of the quantum Euclidean group $${{\cal O}_q}({E_2})$$ is smash product with its Hopf dual $${U_q}({e_2})$$ . For algebra Dq(E2), explicit descriptions prime, primitive and maximal spectra are obtained. All prime factors presented as generalized Weyl algebras. As a result, we obtain that has no finite-dimensional representations, cannot have structure. automorphism ...