Boundedness for surfaces in weighted P^4

Ellingsrud and Peskine (1989) proved that there exists a bound on the degree of smooth non general type surfaces in P^4. The latest proven bound is 52 by Decker and Schreyer in 2000. In this paper we consider bounds on the degree of a quasismooth non-general type surface in weighted projective 4-space. We show that such a bound in terms of the weights exists, and compute an explicit bound in simple cases

Moduli spaces of polarised symplectic O'Grady varieties and Borcherds products

We study moduli spaces of O'Grady's ten-dimensional irreducible symplectic manifolds. These moduli spaces are covers of modular varieties of dimension 21, namely quotients of hermitian symmetric domains by a suitable arithmetic group. The interesting and new aspect of this case is that the group in question is strictly bigger than the stable orthogonal group. This makes it different from both the K3 and the K3^[n] case, which are of dimension 19 and 20 respectively

K -theory of quasi-toric manifolds

In this note we shall give a description of the K-ring of a quasi-toric manifolds in terms of generators and relations. We apply our results to describe the K-ring of Bott-Samelson varieties

An Overview of environmental issues and protection measures in Indian non-ferrous plants

In the industrial scenario of the country, non-ferrous industry plays a predominant role producing variety of metals and alloys for application in chemical, petrochemical, structural, power and engineering sectors. Base metal industries have witnessed remarkable changes in the past two decades besides registering considerable growth. But, most of these base metal industrial developments are generally associated with environmental degradation viz., by way of discharge of wastes into air, natural water bodies or subsoil. Release of harmful gases and suspended particulate matters (SPM) into air leads to ecological imbalance, resulting in de¬struction of natural life cycle of flora and fauna and many other associ¬ated harmful effects. Environmental degradation has become one of the most pressing problems facing India today. Tackling the pollution prob¬lem needs innovative and effective approach and industries should be encouraged to adopt non-polluting technologies rather than seeking to regulate the discharged toxic effluents. This critical review includes en¬vironmental impacts due to base metal production, approaches to envi¬ronmental improvement and finally examines various options to prevent pollution in base metal industries