In Germany there are about fifteen years of experience in the planning and construction of farm-scale biogas plants. In the meantime, approximately 1,600 biogas plants are in operation on farms. This is primarily due to investment funding and payment for each kWh delivered to the public energy grid. In general, three different kinds of digester types are in use for anaerobically treating manure...

Three full-scale Australian wastewater treatment plants are reviewed to present the ‘lessons learnt’ so far in developing an improved design and operating strategy able to efficiently achieve biological nitrogen removal and phosphorus removal. The success of the ‘state of the art’ wastewater treatment plants is based on the development and refinement of existing nutrient removal process models,...

While small-scale studies show that more diverse native communities are less invasible by exotics, studies at large spatial scales often find positive correlations between native and exotic diversity. This large-scale pattern is thought to arise because landscapes with favorable conditions for native species also have favorable conditions for exotic species. From theory, we proposed an alternat...

The Polar Frontal Zone, although predominantly a surface feature, forms a natural northernmost boundary for defining the Southern Ocean, and relatively few benthic organisms have distributions which cross this boundary. Many Antarctic benthic plants and animals have circumpolar distributions but some broad geographical subdivisions may be made. Detailed studies of community distribution are few...

Small-scale plants that produce biodiesel have many social, economic and environmental advantages. Indeed, small significantly contribute to renewable energy production rural development. Communities can use/reuse local raw materials manage independently processes obtain biofuels by essential, simple, flexible cheap tools for self-supply. The review understanding of recent is essential identify...

Meatpacking consolidated rapidly in the last two decades: slaughter plants became much larger, and concentration increased as smaller firms left the industry. We use establishment-based data from the U.S. Census Bureau to describe consolidation and to identify the roles of scale economies and technological change in driving consolidation. Through the 1970’s, larger plants paid higher wages, gen...