M. E. Turner, J. V. Beckett, and B. Afton
- Published in print:
- 2001
- Published Online:
- January 2010
- ISBN:
- 9780198208044
- eISBN:
- 9780191716577
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198208044.003.0004
- Subject:
- History, British and Irish Early Modern History, British and Irish Modern History
This chapter tests the traditional appreciation of farming in the past, based on crop rotations of two or three crops followed by a fallow year, against the evidence-based practice of 18th- and ...
More
This chapter tests the traditional appreciation of farming in the past, based on crop rotations of two or three crops followed by a fallow year, against the evidence-based practice of 18th- and 19th-century farmers. Not only was farming more complex than this, but it also changed and therefore evolved according to farmers' assessments of the market and the diffusion of new crops and techniques. Through measurements derived from farmers' records, the magnitude of this evolution is measured and in particular the temporal diffusion of the Norfolk four course systems of new crops based on the nitrogen cycle is assessed. At the same time, there was a revolution taking place in soil improvements through soil conditioning and fertilizing, and these are also measured and assessed.Less
This chapter tests the traditional appreciation of farming in the past, based on crop rotations of two or three crops followed by a fallow year, against the evidence-based practice of 18th- and 19th-century farmers. Not only was farming more complex than this, but it also changed and therefore evolved according to farmers' assessments of the market and the diffusion of new crops and techniques. Through measurements derived from farmers' records, the magnitude of this evolution is measured and in particular the temporal diffusion of the Norfolk four course systems of new crops based on the nitrogen cycle is assessed. At the same time, there was a revolution taking place in soil improvements through soil conditioning and fertilizing, and these are also measured and assessed.
Robert H. Swendsen
- Published in print:
- 2012
- Published Online:
- December 2013
- ISBN:
- 9780199646944
- eISBN:
- 9780191775123
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199646944.003.0011
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter discusses reversible, irreversible, and quasi-static thermodynamic processes. Heat engines, refrigerators, air conditioners, and heat pumps are analysed and their optimal efficiencies ...
More
This chapter discusses reversible, irreversible, and quasi-static thermodynamic processes. Heat engines, refrigerators, air conditioners, and heat pumps are analysed and their optimal efficiencies are calculated.Less
This chapter discusses reversible, irreversible, and quasi-static thermodynamic processes. Heat engines, refrigerators, air conditioners, and heat pumps are analysed and their optimal efficiencies are calculated.
Peter Rez
- Published in print:
- 2017
- Published Online:
- December 2017
- ISBN:
- 9780198802297
- eISBN:
- 9780191840708
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198802297.003.0003
- Subject:
- Physics, Geophysics, Atmospheric and Environmental Physics
Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat ...
More
Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat transfer from air exchanges with the outside. For large buildings, such as offices and factories, the greater volume-to-surface ratio means that air exchanges are more significant. Lights, people and equipment can make significant contributions. Since the energy used depends on the difference in temperature between the inside and the outside, local climate is the most important factor that determines energy use. If heating is required, it is usually more efficient to use a heat pump than to directly burn a fossil fuel. Using diffuse daylight is always more energy efficient than lighting up a room with artificial lights, although this will set a limit on the size of buildings.Less
Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat transfer from air exchanges with the outside. For large buildings, such as offices and factories, the greater volume-to-surface ratio means that air exchanges are more significant. Lights, people and equipment can make significant contributions. Since the energy used depends on the difference in temperature between the inside and the outside, local climate is the most important factor that determines energy use. If heating is required, it is usually more efficient to use a heat pump than to directly burn a fossil fuel. Using diffuse daylight is always more energy efficient than lighting up a room with artificial lights, although this will set a limit on the size of buildings.
