New spectrophotometry from 1.5 to 2.5 /zm is reported for the Uranian satellites Titania, Oberon, and Umbriel. A spectrum of the rings of Uranus from 2.0 to 2.4/zm is also reported. No evidence is found for frost covering the surface of the ring material, consistent with the low albedo of the rings (P~ = 0.03) previously reported by Nicholson and Jones (1980). The surfaces of the satellites are...

The notions of a right quasiregular element and right modular right ideal in a near-ring are initiated. Based on these J 0(R), the right Jacobson radical of type-0 of a near-ring R is introduced. It is obtained that J 0 is a radical map andN(R)⊆ J 0(R), whereN(R) is the nil radical of a near-ring R. Some characterizations of J 0(R) are given and its relation with some of the radicals is also di...

in this note we introduce the notion of weak mccoy rings as a generalization of mccoy rings, and investigate their properties. also we show that, if is a semi-commutative ring, then is weak mccoy if and only if is weak mccoy.

Let R be a ring and let I 6= R be an ideal of R. Then I is said to be a completely prime ideal of R if R/I is a domain and is said to be completely semiprime if R/I is a reduced ring. In this paper, we introduce a new class of rings known as completely prime ideal rings. We say that a ring R is a completely prime ideal ring (CPI-ring) if every prime ideal of R is completely prime. We say that a...