5 research outputs found
Climate impacts of peat fuel utilization chains – a critical review of the Finnish and Swedish life cycle assessments
In recent years there has been a lively debate in Finland and Sweden on the climate impact of peat fuel utilization. The aim of this study was to clarify the contradictions between the Finnish and Swedish studies and provide a better basis for energy policy decision-making by summarizing the recent scientific knowledge about the climate impacts of peat fuel utilization chains based on the life cycle assessment (LCA) methodology. A starting point for this study was to carry out a critical review of Finnish and Swedish life cycle studies of the climate impacts of peat fuel utilization chains. The critical review was conducted according to the recommendations of international standards and its aim was to ensure that the methods, data and interpretation of results were carried out in a scientifically and technically valid way. During the review the available data (mostly published) on the greenhouse gas (GHG) balances and the radiative forcing impacts of GHGs were gathered and updated. The re-calculations showed that the climate impact of "Pristine mire – afforestation" utilization chain is similar to the climate impact of coal utilization, whereas the result of the peat utilization chain "Pristine mire – restoration" is slightly worse than for the coal utilization chain. The results were similar in the reviewed studies. The peat utilization chain "Forestry-drained peatlands – afforestration" causes a slightly higher climate impact on average than the coal utilization chain does. From the viewpoint of peat utilization the result was similar to the result of Finnish study. According to the reviewed studies the use of cultivated peatlands causes the lowest climate impact compared to the climate impacts of the other peatlands. However, cultivated peatlands do not play important role as an extraction area for peat utilization. From the viewpoint of peat utilization the result of cultivated peatland was worse compared to the result produced by the Finnish and Swedish studies. The climate impacts of peat fuel utilization chains are mostly caused by the carbon dioxide released by peat combustion. These emissions are known quite well. However, the emission assessments of different peat types include large uncertainty before, during and after peat extraction. In spite of that it can be said that land change options related to peat extraction and after-treatments have very limited effects on the climate impacts of peat utilization chain
Transfer and patterning of chemical vapor deposited graphene by a multifunctional polymer film
| openaire: EC/FP7/604391/EU//GRAPHENE | openaire: EC/H2020/644076/EU//CoExANGraphene is seeking pathways towards applications, but there are still plenty of unresolved problems on the way. Many of those obstacles are related to synthesis and processing of graphene. Chemical vapor deposition (CVD) of graphene is currently one of the most promising techniques that enable scalable synthesis of high quality graphene on a copper substrate. From the transient metal substrate, the CVD graphene film is transferred to the desired dielectric substrate. Most often, the transfer process is done by using a supporting poly(methyl methacrylate) (PMMA) film, which is also a widely used electron beam resist. Conventionally, after graphene is transferred to the substrate, the supporting PMMA film is removed by organic solvents. Hence, the potential of using the same PMMA layer as a resist mask remains unexplored. Since PMMA is an electron beam resist, the same polymer film can be useful both for transferring and for patterning of graphene. In this work, we demonstrate simultaneous transfer and patterning of graphene by using the same PMMA film. With our demonstrated method, we are able to receive sub-micron resolution very easily. The graphene transfer and its subsequent patterning with the same resist layer may help developing device applications based on graphene and other 2D materials in the near future.Peer reviewe