Biological and ecological characteristics of Diporeia spp. are described including size, growth, life cycle, energy storage, temperature effect, bioturbation, feeding depth and sediment ingestion of Diporeia. Bioaccumulation and toxicity of organic contam

Benthic organisms dwell in sediment-water interface that contains significant amount of organic and inorganic contaminants. Their feeding behavior is highly related with sediment itself and pore water in the sediments, especially in ease of deposit feeder

Since the 1980s, no concepts have been paid more attention to in discussions of environmental policy and natural resource management than ″sustainability″ and ″sustainable development.″ The concepts, however, are still vague and elusive even though they are frequently being used by a wide range of fields including academia. governments, and the private sector. To identify the diversity, range and concepts of sustainability. this paper will conceptualize the theoretical paradigms and social implications of sustainability and will develop general principles in Public policy.

In today's business transactions, it is more and more common to see that the buyers are allowed some grace period before they settle the account with the supplier. In this regard, we analyze the problem of determining the buyer's EOQ when the supplier allows day-terms credit. For the analysis, it is assumed that the buyer's demand rate is a function of the on -hand inventory level and the relevant mathematical model is developed.

This paper analyses the tool switching problem in the dynamic environment, where parts to be processed on a flexible machine arrive randomly. As the total number of tools required to Process a set of parts on the machine is generally larger than the available magazine storage capacity, tool switches between parts are usually necessary. We assume that tool switching must be made just before the processing of the parts. Since the time required for tool switches can be significant relative to processing time and cause the processing of parts to be delayed, it is desirable to minimize the number of tool switches. Therefore, we present one heuristic algorithm to minimize the total number of tool switches and the t)reposed heuristic is compared with the KTNS (Keep Tool Needed Soonest) policy on randomly generated problems.