Visar resultat 16 - 20 av 853 avhandlingar innehållade ordet fossil.
Sammanfattning : The origin of most of the animal phyla is tied to the Cambrian explosion, a rapid diversification event that took place from about 540 million years ago. This diversification is coupled with a great number of concurrent metazoan body plan innovations such as the development of the coelom, antagonistic muscles and a through-gut. LÄS MER
Sammanfattning : Replacing fossil fuels by biofuels and increasing energy efficiency are often considered to be options for reducing the net emission of greenhouse gases. This thesis presents the results of analyses of energy efficiency, emission and cost of whole energy system chains, from the natural resource to the end user when heating detached houses in a Swedish context. LÄS MER
Sammanfattning : This study examines landscape change in the Province of Jämtland during c. 1000–1750 AD. Settlement and arable cultivation are two of the most important sources in this study. LÄS MER
Sammanfattning : Estonia is the only country in the world, which is totally dependent on oil shale in its energy system. Although this fossil fuel exists in enormous quantities around the world, it has so far not been utilized on a larger scale. The reasons for this have been both economic and, in recent times, ecological. LÄS MER
Sammanfattning : It is a microbial world we live in: microbes outnumber other organisms by several orders of magnitude, and they have great importance for the environment. However, environmental microbes are notoriously difficult to grow in the laboratory, and using culture independent techniques is necessary to expand our view. LÄS MER