| 1. |
- Arneth, Almut, et al.
(författare)
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Terrestrial biogeochemical feedbacks in the climate system
- 2010
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0908 .- 1752-0894. ; 3:8, s. 525-532
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Forskningsöversikt (refereegranskat)abstract
- The terrestrial biosphere is a key regulator of atmospheric chemistry and climate. During past periods of climate change, vegetation cover and interactions between the terrestrial biosphere and atmosphere changed within decades. Modern observations show a similar responsiveness of terrestrial biogeochemistry to anthropogenically forced climate change and air pollution. Although interactions between the carbon cycle and climate have been a central focus, other biogeochemical feedbacks could be as important in modulating future climate change. Total positive radiative forcings resulting from feedbacks between the terrestrial biosphere and the atmosphere are estimated to reach up to 0.9 or 1.5 W m(-2) K-1 towards the end of the twenty-first century, depending on the extent to which interactions with the nitrogen cycle stimulate or limit carbon sequestration. This substantially reduces and potentially even eliminates the cooling effect owing to carbon dioxide fertilization of the terrestrial biota. The overall magnitude of the biogeochemical feedbacks could potentially be similar to that of feedbacks in the physical climate system, but there are large uncertainties in the magnitude of individual estimates and in accounting for synergies between these effects.
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| 2. |
- Kariniemi, M., et al.
(författare)
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Effect of Blanket Properties on Web Tension in Offset Printing
- 2010
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Ingår i: Advances in Printing and Media Technology. - Montreal, Canada.
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Konferensbidrag (refereegranskat)abstract
- VTT and KCL together with several companies in the printing value chain have studied how to control web tension in different parts of a printing press. Extensive trials on printing presses, at pilot scale and at laboratory scale have yielded data for modeling work. Modeling was carried out with statistical methods and by finite element method (FEM). Results show the extent to which paper and printing blankets affect tension formation in a printing press. The main emphasis of this paper is on the effect different printing blanket types have on web tension.It was found that printing blankets have a clear effect on web tension. The degree of tension change is affected by the type of blanket, nip pressure, distances between the blankets, moisture, paper properties and the combination of blanket types in different printing units. Depending on their feeding properties and their effect on web tension, in general, the blankets can be distinguished as negative, neutral and positive. Also the blanket’s effect on web tension is influenced strongly by the type of adjacent blankets. The interactions of fountain solution, ink, nip, blanket and paper had also an effect on the tension formation. The paper experiences a very high rate of strain inside the printing nips, which can affect the paper’s response and therefore tension after the nips. Results suggest that tension cannot be solely predicted with the elastic paper properties measured by conventional methods.
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| 3. |
- Kulmala, M., et al.
(författare)
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Introduction : The Pan-Eurasian Experiment (PEEX) - multidisciplinary, multiscale and multicomponent research and capacity-building initiative
- 2015
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 15:22, s. 13085-13096
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Tidskriftsartikel (refereegranskat)abstract
- The Pan-Eurasian Experiment (PEEX) is a multidisciplinary, multiscale and multicomponent research, research infrastructure and capacity-building program. PEEX has originated from a bottom-up approach by the science communities and is aiming at resolving the major uncertainties in Earth system science and global sustainability issues concerning the Arctic and boreal pan-Eurasian regions, as well as China. The vision of PEEX is to solve interlinked, global grand challenges influencing human well-being and societies in northern Eurasia and China. Such challenges include climate change; air quality; biodiversity loss; urbanization; chemicalization; food and freshwater availability; energy production; and use of natural resources by mining, industry, energy production and transport sectors. Our approach is integrative and supra-disciplinary, recognizing the important role of the Arctic and boreal ecosystems in the Earth system. The PEEX vision includes establishing and maintaining long-term, coherent and coordinated research activities as well as continuous, comprehensive research and educational infrastructure and related capacity-building across the PEEX domain. In this paper we present the PEEX structure and summarize its motivation, objectives and future outlook.
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| 4. |
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| 5. |
- Sorvari, J., et al.
(författare)
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Effect of some printing nip variables on web tension
- 2016
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Ingår i: Nordic Pulp & Paper Research Journal. - : SPCI. - 0283-2631 .- 2000-0669. ; 31:3, s. 491-498
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Tidskriftsartikel (refereegranskat)abstract
- Good runnability of paper web is an important factor for improving performance of printing process. Printing nips cause web tension variations which are known to affect web runnability. However, rather little is known about the exact effect of the nips on web tension. In this work, two dimensional finite element simulations are used to study the effect of some printing nip variables on web tension. In addition, the simulations results are compared with press trial results. The results show that nip blanket type and indentation depth has great impact on web tension. Particularly, mixing of different blanket types in adjacent printing units can cause severe variations to web tension. It is concluded that to attain good runnability the feeding characteristics of the printing blankets as well as the press settings should be known.
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