| 2. |
- Cibecchini, Daniele, et al.
(författare)
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Repairing of a timber truss through two different techniques using timber elements and screwed metal plates
- 2015
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Ingår i: Historical Earthquake-Resistant Timber Framing in the Mediterranean Area. - Cham : Springer International Publishing. - 9783319394916 - 9783319394923 ; , s. 371-381
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Konferensbidrag (refereegranskat)abstract
- Structural reinforcement of timber buildings may be needed due to different reasons such as change of use, deterioration, lack of maintenance, exceptional damaging incidents or loading, to comply with regulatory changes and being retrofitted, or interventions to increase structural resistance.In this work, two different techniques were considered for repair of a timber truss, subjected only to vertical loads, that was previously assessed on laboratory (test facilities of University of Minho) and taken up to failure during a load-carrying test. A collar beam truss, with more than one hundred years, was tested carrying a vertical point load on each main rafter. Failure of the timber truss was located in the sections of the rafters near the loading positions by bending.Repairing techniques, based on the use of timber elements for one of the rafters and on screwed metal plates for the other rafter, were evaluated and compared to the original unstrengthened condition. The efficiency of the combined repairing techniques was evaluated taking into consideration the structural performance of the collar truss, namely its displacement and ultimate load capacity.In this paper, the results of the experimental tests are discussed attending to the analytical calculation of the contribution of the repairing techniques. Also, the different failure scenarios, for original and strengthened truss, were analyzed and compared.
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| 3. |
- Helder, M., et al.
(författare)
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Electricity production with living plants on a green roof : Environmental performance of the plant-microbial fuel cell
- 2013
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Ingår i: Biofuels, Bioproducts and Biorefining. - : Wiley. - 1932-104X .- 1932-1031. ; 7:1, s. 52-64
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Tidskriftsartikel (refereegranskat)abstract
- Several renewable and (claimed) sustainable energy sources have been introduced into the market during the last century in an attempt to battle pollution from fossil fuels. Especially biomass energy technologies have been under debate for their sustainability. A new biomass energy technology was introduced in 2008: the plant-microbial fuel cell (P-MFC). In this system, electricity can be generated with living plants and thus bioelectricity and biomass production can be combined on the same surface. A green roof producing electricity with a P-MFC could be an interesting combination. P-MFC technology is nearing implementation in the market and therefore we assessed the environmental performance of the system with an early stage life cycle assessment (LCA). The environmental performance of the P-MFC is currently worse than that of conventional electricity production technologies. This is mainly due to the limited power output of the P-MFC and the materials presently used in the P-MFC. Granular activated carbon (anode material), gold wires (current collectors), and Teflon-coated copper wires (connecting anode and cathode) have the largest impact on environmental performance. Use of these materials needs to be reduced or avoided and alternatives need to be sought. Increasing power output and deriving co-products from the P-MFC will increase environmental performance of the P-MFC. At this stage it is too early to compare the P-MFC with other (renewable) energy technologies since the P-MFC is still under development.
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