Browsing by Author "Bartlett, Mark D."
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Item Open Access Development of a Simplified Dynamic Testing Device for Turfed Sports Surfaces(Professional Engineering Publishing, 2011-06-01T00:00:00Z) Caple, Matt C. J.; James, Iain T.; Bartlett, Mark D.; Bartlett, David I.The response of natural turf surfaces to loading changes with the force and loading rate applied. Quantification of surface behaviour to athlete loading is complicated by the lack of devices that replicate forces, stresses and loading rates of athletes that can be specifically used on natural turf. To address this issue, a vertical dynamic impact testing device, the DST, was developed. The DST consists of a compressed air driven ram which vertically impacts a studded test foot onto the surface using data from biomechanical studies. The vertical dynamic stress of athlete foot strike during running is replicated, using peak force and mean boot contact area data. The ram pressure is adjustable to allow variation of the stress applied upon impact, potentially replicating a range of athlete-surface interactions. Initial laboratory testing indicated that the device was sensitive to changes in soil condition due to variations in impact data. Total penetration time and distance, and surface energy absorption were all significantly greater in prepared ‘soft' soil treatments (p<0.05). Loading rate in the first 50 ms after impact was significantly greater in the ‘hardest' soil treatment (p<0.05). Future research work will determine in-situ behaviour of actual playing surfaces, compare device loading rates to those of athletes, and assess surfaces to a range of stresItem Open Access The ecology and control of earthworms on golf courses(Cranfield University, 2006-12) Bartlett, Mark D.; Ritz, K.; Harris, Jim A.; James, IainEarthworm casts on golf courses affect the playability of the turf and can potentially damage mowing equipment. Traditionally this problem has been limited using chemical controls. It is estimated that 0.6% of the total UK land surface is occupied by golf courses, therefore, the land management strategies which green keepers adopt with respect to the application of chemicals has a major environmental impact. The aim of this thesis was to investigate the ecology and potential control of earthworm casting in golf turf in environmentally sustainable ways. A quadrat survey of earthworm casts was conducted over two years at five golf courses in Bedfordshire and Buckinghamshire, UK. Using generalized linear models and forward multiple stepwise regression, an internally validated predictive model of earthworm casting activity was constructed. Annual activity on surfaces was predicted using five physicochemical parameters of which C: N and total inorganic nitrogen were the most important. Environmental parameters were also used to predict monthly earthworm activity, with evapotranspiration and rainfall representing the most significant variation. ' Mustard extraction surveys were used to investigate species diversity and community structure of earthworms. Four dominant species were identified (Aporrectodea rosea, Lunibricus rubellus, Aporrectodea longa and Lumbricus terrestris). It is likely that A. longa and L. terrestris, the two must abundant anecic forms, cause the greatest problems to green keepers as these are the largest of the four earthworm species. The microbial community of soil represents the earthworm's primary food source. An analysis of the microbial community size (using chloroform-extraction) and community structure (using phospholipid fatty acid [PLFA] analysis) showed that different surfaces found on golf courses supported significantly distinct and consistent microbial communities. Differences in population size and structure were evident at different depths through all golf course soil profiles investigated. Individual surface types were comparable, irrespective of geographical location. Therefore different surfaces and depths through the soil profile on golf courses represent different earthworm habitats. An investigation of the effects of different construction techniques and materials used in the golf industry on the rate of earthworm cast formation was made. This showed no effect of construction on the vertical distribution of earthworms, but the rate of casting increased on the sand dominated surfaces. It is proposed that this is due to the lower calorific value that this soil represents to the earthworms. This knowledge was applied in an earthworm cast mitigation experiment, reducing casting rates by stimulating the size of the microbial community with glucose solution. Control through physical exclusion of earthworms to the surface using a buried mesh was also trialled and significantly reduced earthworm casts, however no causal mechanism could be elucidated. This study has advanced the understanding of earthworm ecology on golf courses, deriving mechanistic understandings of this system as a whole. This will lead to a more environmentally sustainable approach to the control of earthworms on golf courses.Item Open Access Literature review on the potential effects of electromagnetic fields and subsea noise from marine renewable energy developments on Atlantic salmon, sea trout and European eel. Scottish Natural Heritage Commissioned Report(2011-02-28T00:00:00Z) Gill, Andrew B.; Bartlett, Mark D.Background This report reviews the current state of knowledge with regard to the potential for three fish species of conservation importance, namely Atlantic salmon (Salmo salar), sea trout (Salmo trutta) and European eel (Anguilla anguilla), to be affected by marine renewable energy developments (MRED). The focus is on marine wave and tidal power developments that will generate electricity offshore, which will then be transferred to land by subsea cable. During construction and operation, the marine renewable energy (MRE) devices are expected to cause a number of disturbances to the marine environment including electromagnetic fields (EMF) emissions and subsea sounds (generally referred to as ‘noise'). Such disturbances were assessed to meet the following aims: To determine the current understanding of the effects of EMFs and noise associated with the installation and operation of MREDs, on the behaviour of three species: S. salar, S. trutta and A. anguilla. To determine the gaps in current knowledge and identify research requirements.Main findings The availability and quality of the information on which to base the review was found to be limited with respect to all aspects of the fishes migratory behaviour and activity, both before and after MRE development; this makes it difficult to establish cause and effect. The main findings were: S. salar and A. anguilla can use the earth's magnetic field for orientation and direction finding during migrations. S. trutta juveniles, and close relatives of S. trutta, respond to both the earth's magnetic field and artificial magnetic fields. Current knowledge suggests that EMFs from subsea cables and cabling orientation may interact with migrating eels (and possibly salmonids) if their migration or movement routes take them over the cables, particularly in shallow waters (<20m).The effect, if any, could be a relatively trivial temporary change in swimming direction, or potentially a more serious avoidance response or delay to migration. Whether this will represent a biologically significant effect cannot yet be determined. S. salar, S. trutta and A. anguilla are likely to encounter EMF from subsea cables either during the adult movement phases of life or their early life stages during migration within shallow, coastal waters adjacent to the natal rivers. The subsea noise from MRE devices has not been suitably characterised to determine its acoustic properties and propagation through the coastal waters. MREDs that require pile driving during construction appear to be the most relevant to consider, in addition to the time scale over which pile driving is carried out, for the species under investigation. In the absence of a clear understanding of their response to subsea noise, the specific effects on S. salar, S. trutta and A. anguilla remain very difficult to determine for Scottish waters in relation to tidal and wave power. Based on the studies reviewed, it is suggested that fish that receive high intensity sound pressures (i.e. close proximity to the MRED construction) may be negatively impacted to some degree, whereas those at distances of 100's to 1000's of metres may exhibit behaviour responses, the impact of which is unknown and will be dependent on the received sound. During operation there may be more subtle behavioural effects that should be considered over the life time of the MRED. Whether these effects will represent biologically significant impacts cannot yet be determined. The current assumptions of limited effects are built on an incomplete understanding of how the three species move around their environment and interact with natural and anthropogenic EMF and subsea noise. A number of gaps in understanding exist, principally whether S. salar, S. trutta and A. anguilla respond to the EMF and/or the noise associated with MREDs in Scottish waters. A number of suggestions for specific studies are highlighted in the final section of the report.