5,138 research outputs found

    Characterisation of the VELO High Voltage System

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    The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence that the high voltage system can be safely used and demonstrate that low noise is produced by the power supplies

    Entrepreneurship and failure: two sides of the same coin?

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    This paper attempts to shed light on the nexus of relationships existing between failure, bankruptcy, institutional context, and local characteristics on one hand and entrepreneurship, firm survival, and performance on the other. The aim is to provide a larger vantage point from which to read the research included in this issue with the overall ambition to contribute to a better understanding of our entrepreneurial societies and the role of failure within markets. In this respect, the focus here is mainly on the institutions governing the bankruptcy procedures which do much more than simply regulating the exit of insolvent firms and protecting creditors’ investments, minimizing the social cost of failures. They set up the revolving doors through which creditors can reinvest the recovered capital in new entrepreneurial projects and failed entrepreneurs can bring back to the market their skills and their entrepreneurial spirit for fostering new and hopefully successful ventures. Therefore, by managing bankruptcy, the institutions are not only protecting the economy. Instead, they have become a tool of economic policy, devoted to the delicate issue of regulating a physiological event to the market while avoiding too much waste of resources. In a more positive perspective, managing insolvency and failure is also a mean to strengthen competitiveness and growth, making it possible to stimulate the market in reshuffling skills and resources into new activities. A deeper understanding can in turn contribute to the implementation of better and more efficient policies by integrating bankruptcy as a natural component of firm and market life. © 2018 The Author(s)open access</p

    The VELO High Voltage System Control Software

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    This note describes the VELO high voltage control software. The implementation of its structure as a PVSS Finite State Machine is emphasized. The main error conditions that may occur during operation is also discussed. The VELO HV software conforms to the specification of the VELO

    Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings

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    Coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited by pulsed DC reactive sputter deposition on Si(100) at a temperature of 550 {\deg}C. XRD showed three different crystal structures depending on V-metal fraction in the coating: {\alpha}-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, 63 - 42 at.% V. At lower V-content, 18 and 7 at.%, a gamma-alumina-like solid solution was observed, shifted to larger d-spacing compared to pure {\gamma}-Al2O3. The microstructure changes from large columnar faceted grains for {\alpha}-V2O3 to smaller equiaxed grains when lowering the vanadium content toward pure {\gamma}-Al2O3. Annealing in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 {\deg}C for 42 at.% V and 700 {\deg}C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure {\gamma}-Al2O3-coating, which transformed to {\alpha}-Al2O3 after annealing to 1100{\deg} C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The latter decreased with increasing V-content, larger than 7 at.% V metal fraction. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings

    Toxic metal enrichment and boating intensity: sediment records of antifoulant copper in shallow lakes of eastern England

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    Tributyltin (TBT), an aqueous biocide derived from antifouling paint pollution, is known to have impacted coastal marine ecosystems, and has been reported in the sediment of the Norfolk and Suffolk Broads, a network of rivers and shallow lakes in eastern England. In the marine environment, the 1987 TBT ban has resulted in expanded use of alternative biocides, raising the question of whether these products too have impacted the Broads ecosystem and freshwaters in general. Here we examine the lake sediment record in the Norfolk and Suffolk Broads for contamination by copper (Cu) (as an active biocide agent) and zinc (Zn) (as a component of booster biocides), to assess their occurrence and potential for causing environmental harm in freshwater ecosystems. We find that, after the introduction of leisure boating, there is a statistically significant difference in Cu enrichment between heavily and lightly boated sites, while no such difference exists prior to this time. At the heavily boated sites the onset of Cu enrichment coincides with a period of rapid increase in leisure boating. Such enrichment is maintained to the present day, with some evidence of continued increase. We conclude that Cu-based antifouling has measurably contaminated lakes exposed to boating, at concentrations high enough to cause ecological harm. Similar findings can be expected at other boated freshwater ecosystems elsewhere in the world

    Capacity building for sustainable use of animal genetic resources in developing countries. ILRI-SLU Project progress report for the period 1999-2003

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    To promote a sustainable and improved use of animal genetic resources in developing countries, ILRI in collaboration with the Swedish University of Agricultural Sciences (SLU), and supported by Sida (Sweden), launched a project training the trainers, for national agricultural research systems (NABS) scientists (national university teachers and researchers) in developing countries. The main objectives of the project were to strengthen subject knowledge and skills, and teaching and communication skills of scientists teaching and supervising students in animal breeding and genetics at least up to MSc level. Other objectives were to catalyse curriculum development, stimulate contacts and networking, and to develop computer-based training resources relevant for use by NARS scientists in teaching and research. This capacity building project was an integrated component of the ILRI research agenda on Animal Genetic Resources. It was also an endeavour by ILRI to collaborate with and strengthen NARS institutions and scientists. The project was initially planned to include regions in sub-Saharan Africa, SouthEast Asia and South Asia, resources allowing, Latin America. The activities in each region or sub-region included: planning activities (questionnaire, country visits, planning workshop), training course for university teachers and researchers (three weeks, combining training in animal genetics/breeding and teaching methodologies), development of an Animal Genetics Training Resource' (on CD-ROM, and later also on the Web), follow-up activities, including impact assessment (questionnaires and follow-up workshops). During the period 1999 to 2003 a full round of activities was completed for sub Saharan Africa. The training course was conducted for Eastern/Southern Africa (20 scientists from 10 countries) and for Western/Central Africa (18 scientists from 10 countries). The planning and follow-up workshops were performed jointly for the region. In addition, the planning activities and training course (18 scientists from 9 countries) were completed for South-East Asia. Version 1 of the computer-based training resource (CD) was released in late 2003. The resource contains modules, i.e. core texts on issues related with farm animal genetic resources, quantitative methods and teaching methods, and Resources containing case studies, breed information, maps, examples, exercises, video clips, a glossary and a virtual library. It also contains references to web links, books and other CDs. The participants found the training courses very useful; average score for Overall Impression was 8.2 (scale 1-9). They also indicated that the computer-based training resource would be a valuable tool both in teaching and in research, but had not yet had a chance to explore and use it fully. Impact assessments for Africa (questionnaire and follow-up workshop) showed that the training course has already had a substantial impact in many of the participants. Impact assessments for Africa (questionnaire and follow-up workshop) showed that the training course has already had a substantial impact in many of the participants' home institutions, both on teaching methods and on course content. Students have shown more interest and understanding of animal breeding and genetics. The impact on participants' research has been just as large; more focus on research involving indigenous animal genetic resources, improved research proposal writing, research methodologies and science communication skills, and also more efficient supervision of students' research. Many of the participants have actively disseminated materials and experiences from the course to colleagues in their home institutions. Other important outcomes have been increased contacts and an open e-mail network `Afrib' formed by the African course participants. The project also strengthened Swedish knowledge and expanded PhD activities on animal genetic resources in developing countries; these were valuable `spin-off effects' of the project. The 'training the trainers' approach adopted in the ILRI-SLU project seems to be a good model for effective capacity building to promote a sustainable use of animal genetic resources in developing countries. The approach was innovative and has functioned well; the model could be extended to other disciplines. Furthermore, linking universities from the North to those of the South, with a CGIAR institute playing both a facilitating and catalytic role was beneficial. The project will now proceed to South Asia and version 2 of the computer-based training resource will be developed. More impact analyses will also be performed
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