1,543 research outputs found
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The Impacts of Heather and Grassland Burning in the Uplands: Creating Sustainable Strategies
No full textBoth nationally and globally, UK upland peat is an important store of carbon
as well as a source of other important ecosystem services. However,
concerns have been raised regarding the stability of these stores.
Significant increases in water colour and dissolved organic carbon (DOC)
from catchments draining upland peat have been observed across the UK.
Unlike many boreal peats, the peat soils of UK uplands are heavily managed
for sheep grazing and recreational shooting. Productivity of these
landscapes has been increased through managed burning of the vegetation.
Burning has been linked with increases in water colour and inappropriate
burning can lead to ‘unfavourable’ conditions in these landscapes.
This thesis presents the results from a monitoring programme at Moor
House National Nature Reserve. Results show that burning does not lead to
dramatic increases in DOC and that longer rotations may have benefits for
carbon by reducing water colour. Increases in the occurrence and changes
in the quality of runoff water following burning could help explain changes in
water quality parameters such as DOC.
Experimental studies into biomass loss during burning, combined with a
survey of a wildfire, have shown that the production of char is an important
carbon store that should be accounted for in fire prone upland settings.
Modelling studies suggest that rotation lengths of 15 years are suitable for
char production and that on these longer rotations char becomes a more
important carbon store than any remaining unburnt biomass or litter.
Therefore this work would suggest that longer rotations may have benefits
for carbon storage and water quality. Longer rotations may be sustainable in
some areas but that this is unlikely to be appropriate across the entire of the
UK. The caveats to this work should always be presented and local
knowledge be consulted when drawing up management plans
Roughness Induced Boundary Layer Transition in Incompressible Flow
No full textThe fluid dynamics process leading to laminar-turbulent transition behind an isolated roughness element is investigated in the incompressible regime using particle image velocimetry. The study covers the effect of roughness size and geometry on the promotion of transition. The measurement domain covers a large streamwise range from the near wake to the onset of the turbulent regime. Planar PIV measurements reveal the basic flow pattern and the turbulent structure of the flow characterizing by the velocity fluctuation statistics (RMS of the streamwise and wall-normal velocity component and Reynolds shear stress). The high Reynolds shear stress level reaching the region near the wall in the downstream area indicates the onset of turbulent boundary layer
Aspects of the ecology of the Lepidoptera associated with heather Calluna vulgaris.
No full textAvailable from British Library Document Supply Centre- DSC:DX182730 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Keterampilan Hukum, Panduan untuk Mahasiswa, Akademisi dan Praktisi
No full textSkills book for Indonesian students and lawyers in Indonesian, based on the skills method of the Faculty of Law of Maastricht University. Each chapter has been written by a different author, but the overall structure is based on the structure of Vaardigheden voor juristen
100 years of change: examining agricultural trends, habitat change and stakeholder perceptions through the 20th century
No full text1. The 20th century has witnessed substantial increases in the intensity of agricultural land management, much of which has been driven by policies to enhance food security and production. The knock-on effects in agriculturally dominated landscapes include habitat degradation and biodiversity loss. We examine long-term patterns of agricultural and habitat change at a regional scale, using the Peak District of northern England as a case study. As stakeholders are central to the implementation of successful land-use policy, we also assess their perceptions of historical changes. 2. In the period 1900 to 2000, there was a fivefold rise in sheep density, along with higher cattle density. We found a reduction in the number of farms, evidence of a shift in land ownership patterns, and increased agricultural specialization, including the virtual disappearance of upland arable production. 3. Despite previous studies showing a substantial loss in heather cover, we found that there had been no overall change in the proportion of land covered by dwarf shrub moor. Nonetheless, turnover rates were high, with only 55% of sampled sites maintaining dwarf shrub moor coverage between 1913 and 2000. 4. Stakeholders identified many of the changes revealed by the historical data, such as increased sheep numbers, fewer farms and greater specialization. However, other land-use changes were not properly described. For instance, although there had been no overall change in the proportion of dwarf shrub moor and the size of the rural labour force had not fallen, stakeholders reported a decline in both. Spatial heterogeneity of the changes, shifting baselines and problems with historical data sources might account for some of these discrepancies. 5. Synthesis and applications. A marked increase in sheep numbers, combined with general agricultural intensification, have been the dominant land-use processes in the Peak District during the 20th century. Stakeholders only correctly perceived some land-use changes. Policy and management objectives should therefore be based primarily on actual historical evidence. However, understanding stakeholder perceptions and how they differ from, or agree with, the available evidence will contribute to the successful uptake of land management policies and partly determine the costs of policy implementation
Goda Karte
No full textStamoed certificate which reads; Edmonton Latvian Society Imanta. F.J. Baker1.0 Imanta, 1.1.1 Historyof Imanta in Albert
Agglomeration in suspension: A study of mechanisms and kinetics
No full textMechanical, Maritime and Materials Engineerin
High-resolution EM-CCD scintillation gamma cameras
No full textThe development of medical imaging techniques has dramatically changed clinical practice and biomedical science in the 20th century. Nuclear Medicine imaging techniques reveal the function of organs and tissues in vivo with the aid of radioactively labeled tracer molecules. These techniques, such as Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), are clinically applied in the fields of neurology, oncology, cardiology, skeletal and thyroid imaging. Applied to small animals, these techniques are important tools in development of better diagnostics and new drugs and fundamental biological research. For small animal SPECT systems, pinhole magnification enables image resolutions below 0.3 mm using conventional Anger cameras with an intrinsic spatial resolution of only 3 to 4 mm. There is a large desire to improve the spatial resolution of the gamma detectors to further improve the preclinical and clinical SPECT performance as well as to make systems more compact. This thesis focuses on EM-CCD based scintillation gamma cameras with a very high spatial resolution, more than 10 times better than conventional Anger cameras. Therefore these EM-CCD gamma cameras are a candidate for the next generation of pre-clinical-SPECT scanners. In pinhole SPECT cameras the spatial resolution is severely degraded for gamma photons incident at an angle, called the depth-of-interaction effect. We showed that this effect can be overcome using a novel curved scintillator geometry which results in a scintillation light centroid independent of the depth-of-interaction. Alternatively we strongly reduced the depth-of-interaction effect by using a multi scale algorithm that detects the scintillation depth. This depth is determined by modelling the variation of the scintillation light spread with depth. If we also take the statistics of the detector into account using a Maximum Likelihood scintillation detection algorithm the energy resolution of the detector improves significantly. Furthermore, using the Cramer Rao lower bound we showed that the EM-CCD based gamma camera performance is very sensitive to the scintillator light yield and the Clock Induced Charge (CIC) and dark current noise. A feasible reduction of these noise sources would improve the gamma camera performance significantly.RRRApplied Science
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