Sökning: "barriärer"
Visar resultat 16 - 20 av 74 avhandlingar innehållade ordet barriärer.
16. Interest in Material Cycle Closure? Exploring Evolution of Industry's Responses to High-grade Recycling from an Industrial Ecology Perspective
Sammanfattning : Many anthropogenically-produced or beneficiated materials contained in “end-of-life” products retain a great proportion of the invested manufacturing work when discarded. Very few such materials are reconstituted and applied in new products at the same material inherent quality level as in their first lifetime – a process known as “closed-loop recycling”. LÄS MER
17. Carrier dynamics in blue and green InGaN LED structures
Sammanfattning : This thesis focuses on effects that are critical to achieving high internal quantum efficiency (IQE) in GaN-based light-emitting diodes (LEDs) that emit in a broad spectral range, from violet to green-yellow. These effects include interwell carrier transport in multiple quantum well (QW) structures, lateral transport in the QW plane, and radiative and nonradiative recombination. LÄS MER
18. Tunneling Based Electronic Devices
Sammanfattning : This thesis concerns different kinds of tunneling based devices all showing negative differential resistance. The thesis is divided in three parts, resonant tunneling transistors, Esaki diodes and coupled zero dimensional systems. LÄS MER
19. Virtual Mobility and Pollution Prevention - The Emerging Role of ICT Based Communication in Organisations and its Impact on Travel
Sammanfattning : Information and Communication Technologies change the way we work and communicate, enabling us to telework and to have virtual meetings - collaborating without a physical meeting. This can influence the need for commuting and business travel by provision of access to an activity without mobility - virtual mobility. LÄS MER
20. Towards a sustainable automotive industry : experiences from the development of emission control systems
Sammanfattning : From the mid-1970s and on, the contribution to air pollution of carbon monoxide, hydrocarbons and nitrogen oxides from gasoline passenger cars in the developed world has been reduced through co-evolution of regulation and commercial introduction of catalytic emission control technology, now part of hundreds of millions of cars, trucks and buses worldwide. This dissertation is a disaggregated study of the global introduction of catalytic emission control technology as a measure to reduce local air pollution. LÄS MER