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- Stirling, R., et al.
(author)
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Global survey on durability variation – on the effect of the reference species
- 2016
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In: Proceedings of the International Research Group Annual Meeting 2016.
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Conference paper (other academic/artistic)abstract
- Climate change due to anthropogenic emissions is the largest environmental challenge of ourtime. Forest-based value chains play an important role in reducing the accumulation of CO2 in the atmosphere. Maximizing the use of wood to tackle climate change requires improved understanding of the service life of timber products. This information can best be obtained from field testing and while there is an abundance of field performance data from sites all over the world, most of the data are not available in a form that can be utilised for service life models.The IRG Durability Database aims to improve the usability of existing performance data and create added value for durability research and service life prediction. The present paper takes the first steps in comparing global field test performance data from the IRG Durability Database for non-durable reference species. Data were obtained from six species above ground and ground contact field tests from 36 sites around the world. For each dataset, decay rates and service life (where applicable) were calculated. Datasets were then grouped together based on test method and species. Decay rate was faster and more uniform in ground contact than above ground. Inground contact, beech decayed most rapidly, followed by Norway spruce and Scots pines apwood. All appeared to be suitable for use as reference species, however slow-grown spruce should be avoided. There were no statistically significant correlations between ground contact decay rate and the Scheffer Climate Index (SCI). In above ground tests, differences in decay ratewere largely related to differences in moisture dynamics. Species with the greatest absorption and retention of water decayed most rapidly. Test methods that absorbed and retained the most moisture (e.g. painted L-joints) resulted in more rapid decay. Above ground decay rate and SCI were significantly correlated in two data sets that had a wide range of SCI values. Correlations were not significant when only European test sites were included. Estimating decay rate from field testing results in highly variable data. Comparing data from global test sites is made more difficult by the absence of common field testing standards.
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| 2. |
- De Windt, L., et al.
(author)
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Reactive transport modeling of leachate evolution of MSWI bottom ash used as road basement : Hérouville (France) and Dåva (Sweden) sites
- 2009
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Conference paper (other academic/artistic)abstract
- The recycling of municipal solid waste of incineration (MSWI) bottom ash as aggregates for road basement requires a better characterization of the evolution of leachate chemistry over a timescale of many decades. In this paper, a common reactive transport model is applied to the Hérouville (France) and Dåva (Sweden) pilot roads whose leachate emissions have been sampled during 10 and 6 years, respectively. The model considers simultaneously the hydrodynamic processes (rain water infiltration, advective and diffusive transport), pH-buffering and solubility-controlled processes by secondary minerals, ageing by atmospheric carbonation, and the leachate chemistry (major elements and trace metals such as Al, Cu, Pb). The evolution of pH is fairly well simulated with the following pH-buffering sequence: portlandite, calcium silicate hydrate (CSH), ettringite and, finally, calcite. The quantity of CO2 dissolved in the percolating rain water is generally not sufficient to explain the pH evolution and carbonation processes, requiring atmospheric gaseous inputs. The relation between pH evolution and element release is discussed for both sites. Calculated Pb release is overestimated when based on solubility-controlled mechanisms only. Edge effects are shown to be important at both sites with an emphasis of carbonation and release of non reactive elements. Temperature has no significant effect on the calculated leachate chemistry in the range of 5 - 30° C, except at high pH.
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| 3. |
- de Windt, T. S., et al.
(author)
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Treatment and Prevention of (Early) Osteoarthritis Using Articular Cartilage Repair-Fact or Fiction? A Systematic Review
- 2013
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In: Cartilage. - : SAGE Publications. - 1947-6035 .- 1947-6043. ; 4:3 SUPPL.
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Journal article (peer-reviewed)abstract
- Early osteoarthritis (OA) is increasingly being recognized in patients who wish to remain active while not accepting the limitations of conservative treatment or joint replacement. The aim of this systematic review was to evaluate the existing evidence for treatment of patients with early OA using articular cartilage repair techniques. A systematic search was performed in EMBASE, MEDLINE, and the Cochrane collaboration. Articles were screened for relevance and appraised for quality. Nine articles of generally low methodological quality (mean Coleman score 58) including a total of 502 patients (mean age range = 36-57 years) could be included. In the reports, both radiological and clinical criteria for early OA were applied. Of all patients included in this review, 75% were treated with autologous chondrocyte implantation. Good short-term clinical outcome up to 9 years was shown. Failure rates varied from 8% to 27.3%. The conversion to total knee arthroplasty rate was 2.5% to 6.5%. Although a (randomized controlled) trial in this patient category with long-term follow-up is needed, the literature suggests autologous chondrocyte implantation could provide good short- to mid-term clinical outcome and delay the need for total knee arthroplasty. The use of standardized criteria for early OA and implementation of (randomized) trials with long-term follow-up may allow for further expansion of the research field in articular cartilage repair to the challenging population with (early) OA. © The Author(s) 2013.
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