and Literature Rev iew Chapter 1 1. INTRODUCTION AND LITERATURE REVIEW The exploration for oil and gas in ever increasing water depths has given an impetus to research efforts on the behaviour of offshore structures under ocean environment. These structures are continuously subjected to environmental loading because of waves, wind and current. A response analysis is required to assess the safety of offshore structure under severe storm conditions as well as for estimation of damage caused by less severe but more frequently occuring sea states. A majority of the reported failures in the life time of offshore structures are in fact fatigue failures. The offshore structures are usually built in the form of welded tubular structures. The joints of these tubular members experience the fatigue damage mainly due to small defects in welding which act as crack initiators, high stress concentrations and the variable loads. The variable loads due to the ocean waves cause cyclic stress variation in the structural members and the accumu lated effect of these stresses results in the fatigue failure."

Asian Atmospheric Pollution: Sources, Characteristics and Impacts provides a concise yet comprehensive treatment of all aspects of pollution and air quality monitoring, across all of Asia. It focuses on key regions of the world and details a variety of sources, their transport mechanism, long term variability and impacts on climate at local and regional scales. It also discusses the feedback on pollutants, on different meteorological parameters like radiative forcing, fog formations, precipitation, cloud characteristics and more. Drawing upon the expertise of multiple well-known authors from different countries to underline some of these key issues, it includes sections dedicated to treatment of pollutant sources, studying of pollutants and trace gases using satellite/station based observations and models, transport mechanisms, seasonal and inter-annual variability and impact on climate, health and biosphere in general. Asian Atmospheric Pollution: Sources, Characteristics and Impacts is a useful resource for scientists and students to understand the sources and dynamics of atmospheric pollution as well as their transport from one continent to other continents, helping the atmospheric modelling community to model different scenarios of the pollution, gauge its short term and long term impacts across regional to global scales and better understand the ramifications of episodic events.