| 1. |
- Nilsson, David, 1968-
(författare)
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Paving the way for pro-poor and sustainable WASH : The role of local innovation
- 2020
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Rapport (populärvet., debatt m.m.)abstract
- Although billions of people worldwide have gained access to basic drinking water and sanitation during the last two decades, data suggests that ‘leaving no one behind’ by 2030 would require doubling the current annual rate of progress1 sanitation and hygiene targets within the Sustainable Development Goals (SDGs. In peri-urban areas, the increasing number of unconnected customers poses additional challenges. Business-as-usual will not address the problems of low coverage, inadequate service levels and poor sustainability of water and sanitation systems. A combination of new technologies with innovative models of service delivery will be needed to close the existing gaps and reduce inequalities. In particular, service providers will need to simultaneously adopt new, informal solutions for unconnected users and more traditional, formal mechanisms to connect more users to the centralized piped infrastructure, through an ambidextrous strategy.”
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| 2. |
- Olofsson, Ulf, et al.
(författare)
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The influence of snow on the tread braking performance of a train : A pin-on-disc simulation performed in a climate chamber
- 2016
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Ingår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : Sage Publications. - 0954-4097 .- 2041-3017. ; 230:6, s. 1521-1530
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Tidskriftsartikel (refereegranskat)abstract
- In trains with tread brakes, the coefficient of friction between the brake block and the railway wheel determines the stopping distance. The blocks have traditionally been manufactured from cast iron. Although these blocks have good braking capacity, their use is often restricted due to the squealing noise they emit. Tests of alternative composite block materials have been successful under summer conditions; however, in regions with snowy winters the use of such materials has been limited due to problems with braking capacity under snowy conditions. This research aims to develop a laboratory-scale test methodology for evaluating the braking capacity of tread brake materials under winter and snowy conditions. A pin-on-disc machine placed in a climate chamber was used for testing, and a block of standard cast iron was compared with blocks of standard composite materials. The results indicated that the blocks of standard composite materials generate a much smoother surface on the counter wheel and a significantly lower friction coefficient under snowy conditions. A second test series evaluated blocks of alternative composite materials, and a candidate material with low noise and a sufficiently high sliding friction coefficient was selected for further study. A third test series examining geometrical changes in the contact surface in terms of milled parallel tracks was performed; it revealed that the braking capacity under winter conditions can be increased by milling actions if the parallel tracks are properly oriented - in this case, at an angle of 45 degrees to the sliding direction.
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