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Improved Material Models for High Strength SteelLarsson, Rikard January 2011 (has links)
The mechanical behaviour of the three advanced high strength steel grades, Docol 600DP, Docol 1200M and HyTens 1000, has been experimentally investigated under various types of deformation, and material models have been developed, which account for the experimentally observed behaviour. Two extensive experimental programmes have been conducted in this work. In the first, the dual phase Docol 600DP steel and martensitic Docol 1200M steel were subjected to deformations both under linear and non-linear strain paths. Regular test specimens were made both from virgin materials, i.e. as received, and from materials pre-strained in various directions. The plastic strain hardening, as well as plastic anisotropy and its evolution during deformation of the two materials, were evaluated and modelled with a phenomenological model. In the second experimental program, the austenitic stainless HyTens 1000 steel was subjected to deformations under various proportional strain paths and strain rates. It was shown experimentally that the material is sensitive both to dynamic and static strain ageing. A phenomenological model accounting for these effects was developed, calibrated, implemented in a Finite Element software and, finally,validated. Both direct methods and inverse analyses were used in order to calibrate the parameters in the material models. The agreement between the numerical and experimental results are in general very good. This thesis is divided into two main parts. The background, theoretical framework and mechanical experiments are presented in the rst part. In the second part, two papers are appended.
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The political career of Henry Marten, with special reference to the origins of republicanism in the Long ParliamentWilliams, Charles Murray January 1954 (has links)
No description available.
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Changes in the status and distribution of mammals of the order Carnivora in Yorkshire from 1600 : county history of the fox, badger, otter, pine marten, stoat, weasel, polecat, American mink, wildcat and domestic catHowes, Colin Anthony January 2009 (has links)
Data derived largely from ecclesiastical (mostly churchwardens') accounts, foxhunting statistics, local scientific society records and 19th and 20th century literature sources from a wide range of published material, have provided detailed evidence of the status and changes in distribution over the past four centuries in Yorkshire for fox (Vulpes vulpes), badger (Meles meles), otter (Lutra lutra), pine marten (Martes martes), stoat (Mustela erminea), weasel (M. nivalis), polecat (M. putorius), American mink (M. vison), wildcat (Felis silvestris) and domestic cat (Felis catus). In the case of the domestic cat, questionnaire surveys quantified population sizes and predatory activity in rural, suburban and urban situations. Evidence of the former distribution of all the carnivores studied provides a credible historical basis for biodiversity action planning and the substantial archived database and bibliography provide further research opportunities.
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Une analyse de la connectivité fonctionnelle du paysage : Etude des déplacements et des flux de gènes chez un mustélidé forestier, la Martre des pins (Martes martes) / Analysis of functional landscape connectivity : Study of movements and genes flow of a forest mustelid, the Pine marten (Martes martes)Bardonnet, Clara 17 December 2015 (has links)
Les modifications du paysage engendrées par les activités humaines sont une des causes majeures du déclin de la biodiversité. En générant une perte de la connectivité fonctionnelle du paysage, elles limitent les déplacements des individus et entraînent la rupture des flux de gènes, processus clés dans le maintien et la persistance des populations. Cependant, le lien entre ces processus et la structure du paysage est encore mal compris. Dans ce contexte, nous avons conduit une étude sur la Martre des pins, une espèce a priori forestière, bien que capable de s’installer durablement dans des paysages fragmentés. A partir de l’analyse de la variabilité génétique de groupes échantillonnées sur 13 sites forestiers à l’échelle de la région Champagne-Ardenne, et du suivi des déplacements d’individus à fine échelle, en milieu continu et fragmenté, nous avons estimé la résistance du paysage aux différents déplacements, c’est-à-dire dans quelle mesure ceux-ci sont freinés ou facilités par les éléments du paysage. Nous avons mis en évidence que les déplacements sont freinés, d’une part par la présence d’une large plaine agricole, et d’autre part, par certaines infrastructures de transport. Nous avons également mis en évidence que les déplacements des martres entre les taches d’habitats sont facilités par la présence de haies et que la hauteur du couvert végétal des habitats non boisés pourrait jouer un rôle dans ces déplacements. Cette étude apporte d’importantes connaissances sur l’écologie des déplacements de la Martre des pins et souligne la nécessité de la prise en compte de la réponse des organismes dans l’établissement des futurs réseaux écologiques. / Landscape changes, generated by anthropogenic activities, are widely recognised as one of the main causes of global biodiversity decline. Leading to a loss of functional landscape connectivity, they disrupt movements and gene flow which play a primordial role for the persistence of populations. However, the relationship between these processes and landscape structure remains unclear. In this context, we studied landscape connectivity in European pine marten, a forest species present in fragmented landscapes. We evaluated landscape resistance, i.e. how landscape features impede or facilitate movements and gene flow, analysing genetic variability of groups sampled in 13 forest sites of the Champagne-Ardenne regional area, and studying individual fine-scale movements in both continuous and fragmented areas. We showed that intensive agricultural plain and certain linear infrastructures could impede movements. In addition, we showed that hedgerows facilitate movements between forest patches and we suggested that vegetation height of open habitats could play a role for these movements. This study provides important insights on movement ecology of the European pine marten and underlines the need to take into account responses of organisms in the establishment of ecological networks.
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Second Growth Forest as Potential Marten Habitat in Western Newfoundland: An Examination of Forest Habitat Structure and Microtine AbundanceSturtevant, Brian R. 01 May 1996 (has links)
The American marten (Martes americana) is associated with large tracts of relatively undisturbed, mature coniferous forests. I examined coarse woody debris (CWO) structure and small mammal abundance with respect to forest age and stem structure within second-growth forests, in comparison with old-growth stands in western Newfoundland. Results suggest that a critical change in marten habitat quality may occur at stand senescence, due to decreased tree competition, more complex subcanopy structure, and increased meadow vole (Microtus pennsylvanicus) abundance.
Analysis of stem structure within a chronosequence of 19 second-growth stands indicated high intertree competition, with dense canopy closure and active self-thinning, until stand senescence at 80 years. Old-growth stands were less dense, offering more canopy openings. CWD volume observed within the chronosequence demonstrated the typical U-shaped temporal relationship observed in other forested systems. Lowest CWD volumes were observed within semimature to mature second growth. Highest levels of both CWD volume and structural complexity corresponded with stand senescence and old growth.
Small mammals were sampled within immature, semimature, mature, and silviculturally overmature coniferous stands in western Newfoundland during 1993 and 1994. Meadow voles were most abundant within overmature stands (P
Results from this study suggest that the critical elements of marten foraging habitat currently are found within a senescent forest stand structure. Further review of the literature and Newfoundland harvest records indicated that anthropogenic disturbance transformed a historically heterogeneous forested landscape into a more contiguous, even-aged, second-growth environment. Using the stand density management diagram, I designed a silvicultural approach to marten habitat management that simulates the structure of older forests within younger stages of forest development.
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Changes in the status and distribution of mammals of the order Carnivora in Yorkshire from 1600. County history of the fox, badger, otter, pine marten, stoat, weasel, polecat, American mink, wildcat and domestic cat.Howes, Colin Anthony January 2009 (has links)
Data derived largely from ecclesiastical (mostly churchwardens¿) accounts, foxhunting statistics, local scientific society records and 19th and 20th century literature sources from a wide range of published material, have provided detailed evidence of the status and changes in distribution over the past four centuries in Yorkshire for fox (Vulpes vulpes), badger (Meles meles), otter (Lutra lutra), pine marten (Martes martes), stoat (Mustela erminea), weasel (M. nivalis), polecat (M. putorius), American mink (M. vison), wildcat (Felis silvestris) and domestic cat (Felis catus). In the case of the domestic cat, questionnaire surveys quantified population sizes and predatory activity in rural, suburban and urban situations. Evidence of the former distribution of all the carnivores studied provides a credible historical basis for biodiversity action planning and the substantial archived database and bibliography provide further research opportunities.
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Fragmentace a savčí predátoři v lesních habitatech: faktory ovlivňující jejich distribuci a výběr prostředí / Fragmentation and mammalian carnivores in forest habitats: variables which affect carnivores distribution and habitat choicePAVLUVČÍK, Petr January 2010 (has links)
The human use of landscape causes fragmentation and loss of original habitats. Different species vary in their sensitivity to habitat loss. Especially carnivores can be more sensitive to decrease of their habitat because of lower abundance of their prey. On the other hand several opportunistic carnivores can profit in human modified habitats. This study was carried out in the České Budějovice basin, Czech Republic during the years 2008 and 2009 and the aim of this study was to determine carnivore{\crq}s habitat preferences in the fragmented landscape. During these two years were seven carnivore species monitored in forest patches by using scent stations. Records of this monitoring were compared with physiognomy of these patches and structure of surrounding landscape.
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A muse of fire : British trench warfare munitions, their invention, manufacture and tactical employment on the Western Front, 1914-18Saunders, Anthony James January 2008 (has links)
The emergence of static warfare on the Western Front in late 1914, encouraged the reinvention of devices associated with siege warfare and the invention of hitherto unknown munitions. These munitions included hand and rifle grenades and trench mortars and their ammunition. At the outbreak of war, the British effectively possessed none of these devices and lacked an infrastructure by which they could be quickly designed, manufactured and supplied to the BEF. The British met this challenge with considerable success and the subsequent proliferation of trench warfare munitions had profound consequences for the evolution of British tactics on the Western Front. This thesis examines the processes by which these devices were invented, developed into manufacturable devices and supplied to the BEF. It considers their novelty in respect to similar devices from the American Civil War and the Russo-Japanese War. It looks at how their technical evolution affected tactical developments. The thesis discusses the relationship between the technical characteristics of these devices and the evolution of their tactical employment on the Western Front. It also considers how the characteristics of certain munitions, such as the Stokes mortar and the Mills grenade, directly effected tactics. It argues that the tactical employment of these munitions was dependent upon their functionality, utility and reliability. The present thesis provides a different model of trench warfare conducted by the British during the First World War and thereby demonstrates the significance of the novel munitions under discussion and the role they played in changing infantry warfare. This thesis also provides a different view of the Ministry of Munitions from that usually offered and argues that certain aspects of the Ministry’s role in providing the BEF with munitions has been overstated by virtue of its having underplayed the work of the War Office, while overlooking that conducted by the Royal Engineers in France.
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Monitoring European pine martens (Martes martes) in Scottish forested landscapesKubasiewicz, Laura M. January 2014 (has links)
Monitoring the distribution, abundance and demography of species is vital to ensure that conservation efforts are appropriate and effective. Monitoring enables evaluation of responses to natural or human disturbance, highlights the need for management interventions and enables these interventions to be assessed and refined. The methods used largely depend on the specific aim of monitoring and behaviour of the target species, as well as the time and spatial scale that monitoring is required to cover. The European pine marten (Martes martes) is one of few remaining mammalian predators native to the UK. Since persecution in the early 19th century resulted in their near extinction, pine martens have recovered part of their former range in Scotland. Their recent recovery and an overlap in territory with vulnerable prey species such as the capercaillie (Tetrao urogallus) make the collection of accurate baseline data and subsequent monitoring of population trends vital for conservation efforts. Faecal counts have traditionally been used to provide a relative measure of population density for pine marten. In most cases, absolute measures of population density require individual identification. Non-invasive genotyping can provide this information but the quality of DNA from these samples is often poor. Here, the process is refined for pine marten faeces (scats) and hair samples. DNA degradation increased significantly for scats exposed to rainfall, with the rate of DNA amplification success reduced by 38% over a 16 day period. Success rates for hair samples were higher when more hair follicles were included in the analysis. Population densities were estimated for three forests in Scotland using a robust combination of non-invasive genotyping of hair samples and spatially explicit capture recapture modelling. Population density estimates of 0.07 (95% CI 0.03 - 0.16) to 0.38 km-2 (95% CI 0.11 - 1.07) were obtained which are within the range of previous estimates for forests elsewhere in Scotland. The first attempt to quantify the relationship between traditional scat counts and home range size was then conducted; a significant negative correlation exists but only when population density is relatively low. Previous studies suggest that pine martens in Western Europe are less forest dependent than those in Eastern Europe. Results from this thesis support this, with populations at the highest density found at sites with intermediate forest cover. This tolerance of lower forest cover is also apparent in the diet. Despite a preference for Myodes voles in populations in Eastern Europe, those in Western Europe show a strong preference for Microtus voles as well as a higher level of frugivory. We assess the autumn diet of four populations in Scotland assess the effect of forest cover and sex on the diet. There was no evidence of differential consumption of Microtus voles or birds between the sexes. Our analysis shows that frugivory is influenced by forest fragmentation, with a 5-fold increase in the occurrence of fruit (from 2% to 10%) as forest cover increased from 4% to 47%. Diversionary feeding has been suggested as a management technique to reduce the depredation of capercaillie by pine martens. This thesis presents the first attempt to quantify the success and cost-efficacy of diversionary feeding for a range of problems (crop damage, threatened safety, livestock depredation) across 30 experimental trials. The strategy proved more effective when targeted towards food-limited populations, and when aiming to alleviate habitat damage or risks to human safety rather than depredation. A novel decision-making framework was developed to aid managers with the initial planning of the strategy and its subsequent implementation within an adaptive format. Further to this, the feasibility of using diversionary feeding with a view to reduce the depredation of capercaillie by pine martens was assessed. Questionnaire responses were collected from people who have provided food for pine martens throughout Scotland. A positive reaction to food was observed, with 58% of respondents reporting that initial visits occurred within one week of placement and 46% reporting that subsequent visits were received daily. These results suggest that diversionary feeding may be a viable option for pine marten management, although testing of its impact on capercaillie productivity would be required.
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Pine marten diet and habitat use within a managed coniferous forestCaryl, Fiona Mae January 2008 (has links)
Increased afforestation and protective legislation in the latter half of the 20th Century allowed the British pine marten Martes martes population to recover from near extinction. Although still largely confined to northern Scotland, the marten population is expanding its size and range by utlising coniferous plantation forests which have become increasingly available. However, little is known about the marten’s ecology in plantation forestry, and less about how they may adapt to changing silvicultural trends. This study investigated aspects of pine marten ecology within Morangie forest, a managed plantation in NE Scotland, with the ultimate aim of formulating management guidelines for modern plantation forests. During the course of the study 11 pine marten were radiotracked and their home ranges mapped to examine marten-habitat associations at several spatial scales. Compositional analysis of habitat based on dominant vegetation type showed that martens established their home ranges in areas dominated by mature forest, whilst showing relative avoidance for open heath moor and grazed pasture. Within home ranges, foraging martens utilised patches of graminoid vegetation, such as those typically associated with Microtus voles, in areas with little or no tree canopy cover. These findings provide unequivocal evidence that fine-scale patches of non-forested habitat provide crucial foraging resources for marten, and therefore ought to be provisioned for in forest management plans. To assist the implementation of these requirements in forest planning, a model was developed to predict the fine scale distribution of Microtus-rich foraging habitat for marten using GIS-based habitat variables that are routinely available to forest managers: topographic wetness index, stand tree height and stand basal area. Management recommendations of ways to improve wind-firm plantation forests as habitats for pine marten are provided. To augment the investigation of marten spatial ecology, the diet of martens was examined seasonally through the analysis of contents from c. 2450 scats, 86 % of which were genetically identified as being pine marten in origin. Marten diets displayed marked seasonality, but small mammals, berries and small birds were the principal foods consumed based on both frequency of occurrence and estimated weight of biomass ingested. Comparison of the relative composition of small mammal species in the diet with those available in the environment revealed that marten displayed an indisputable preference for Microtus voles. Such habits demonstrate that the niche of Scottish martens has diverged from those in mainland populations which predominantly prey upon Clethrionomys voles. A comparison of the marten’s winter diet with those found in studies at similar latitudes (58°N) demonstrated that the Scottish diet was more similar to diets at more southerly latitudes as they contained more fruit and fewer large mammals than typically boreal diets. Investigation of inter-annual variation of the marten’s spring diet from five successive years revealed that Microtus were consistently the most important prey species in the diet each year. Indirect evidence of the relative abundance of Microtus suggested that Microtus populations were non-cyclic. Findings are discussed with reference to the unique ecological circumstances confronting marten in the Scotland; typical of insular populations the UK has a depauperate native fauna in comparison with mainland Europe, in addition to this, mild climatic conditions, particularly over winter, and a historically fragmented landscape appear to have allowed the niche of the Scottish marten to diverge from that considered typical elsewhere in its range. The Scottish marten is dependent on both forested and open habitats, and is both a Microtus specialist and trophic generalist.
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