144 research outputs found

    Investigation wettability of carbon components with the polyurethane binder of resistive composites

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    The research paper deals with influence wettability of carbon components with the polyurethane binder of resistive composites. We have revealed that the polyurethane lacquer wets up to 25 wt. % of C-1 and GE-3 particles, which results in their uniform distribution over the entire volume of the binder and homogeneity of RCMs. Zero wetting of the same weight percentage is observed in the case of K-163 carbon black, which gives rise to caking and distortion of homogeneity of the composite coating after its formation and its further cracking after heat treatment. The wetting capacity of K-163 carbon black in the polyurethane lacquer is improved using a DISPERBYK-2155 dispersing agent in the amount of 10 wt. % with respect to the binder. The resulting experimental data indicate that C-1 particles exhibit the best wettability, hence their adhesion strength with the binder would be higher than that of GE-3 graphite element and K-163 carbon black

    Utveckling av metod för att bedöma behovet av ogrÀsbekÀmpning i spÄr

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    En miljöanpassad och resurseffektiv hantering av ogrÀs i spÄr stÀller krav pÄ god kunskap om vegetationsförhÄllanden för att behovsanpassa bekÀmpningsinsatserna. En automatiserad registrering skulle kunna utgöra ett komplement till dagens manuella inspektioner och skulle över tiden helt eller delvis kunna ersÀtta dessa. En utmaning Àr att hitta en metod som ger en rimlig upplösning i informationen som samlas in, sÄ att den kan hanteras rationellt av berörda aktörer och samtidigt utgöra ett beslutsunderlag med tillrÀcklig precision. Projektet studerade tvÄ automatiserade metoder som kan vara aktuella för Trafikverket att anvÀnda i framtiden: 1) Machine vision metoden utnyttjar kamerasensorer för att kÀnna av sin omgivning i det synliga respektive nÀra infraröda spektrumet. 2) N-sensorn sÀnder ut ljus inom det omrÄde som reflekteras av vÀxternas klorofyll. MÀngden klorofyll ger ett mÀtvÀrde som kan korreleras till biomassan. Valet av teknik beror pÄ vad informationen ska anvÀndas till. Om syftet Àr att översiktligt kartlÀgga vegetationsförekomst i spÄr, för att planera ÄtgÀrder för underhÄll, kan N-sensortekniken vara lÀmplig. Om man över ytan och tiden vill övervaka och kartlÀgga aktuell och precis vegetationsstatus, för att kunna bekÀmpa utvald vegetation med rÀtt insats, Àr machine vision tekniken bÀttre lÀmpad. SÄvÀl machine vision metoden som N-sensortekniken bygger pÄ registrering av data tillsammans med en GPS-positionering. PÄ sikt kan denna information lÀggas i databaser som Àr direkt Ätkomliga för berörda organisationer och t o m online i fÀlt under eller i samband med en bekÀmpningsÄtgÀrd. De tvÄ teknikerna jÀmfördes med manuella (visuella) skattningar av ogrÀsförekomsten. Den visuella skattningen av yttÀckningsgrad av ogrÀs i fÀlt skiljde sig statistiskt mellan olika bedömare. NÀr det gÀller att uppskatta frekvensen (antalet) vedartade vÀxter (trÀd och buskar) inom provytorna sÄ var observatörerna relativt överens. Samma person Àr ofta konsekvent i sitt bedömande, men att jÀmföra med andra personers bedömning kan ge missvisande resultat. Systemet för anvÀndning av informationen om ogrÀsförekomst behöver utvecklas som helhet. TröskelvÀrden för hur mycket ogrÀs som kan tolereras pÄ olika typer av spÄr/driftsplatser Àr en viktig komponent i ett sÄdant system. Klassificeringssystemet ska kunna hantera de krav som stÀlls för att sÀkerstÀlla banans kvalitet och olika förutsÀttningar som trafikförhÄllanden, platsgivna förutsÀttningar för banan och vegetationens egenskaper. Projektet rekommenderar Trafikverket att: diskutera hur tröskelvÀrden för vegetationsförekomst pÄ spÄr kan faststÀllas genomföra registrering av vegetationsförekomst över lÀngre och fler strÀckor med en eller flera av de metoder som studerats i projektet inleda införande av system som effektivt kopplar informationen om vegetation till position inkludera förekomst av vegetation i den registrering som idag sker av spÄrens (banans) tekniska kvalitet och ansluta datamaterialet till övriga underhÄllsrelaterade databaser inrÀtta ett antal representativa ytor dÀr ogrÀsfloran pÄ spÄren regelbundet inventeras och mÀts för att fÄ en bild av den lÄngsiktiga utveckling som grund för sÀkrare prognoser för vegetationsutveckling sÀkerstÀlla att nödvÀndiga utbildningsinsatser genomför

    Growth of Patterned Surfaces

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    During epitaxial crystal growth a pattern that has initially been imprinted on a surface approximately reproduces itself after the deposition of an integer number of monolayers. Computer simulations of the one-dimensional case show that the quality of reproduction decays exponentially with a characteristic time which is linear in the activation energy of surface diffusion. We argue that this life time of a pattern is optimized, if the characteristic feature size of the pattern is larger than (D/F)1/(d+2)(D/F)^{1/(d+2)}, where DD is the surface diffusion constant, FF the deposition rate and dd the surface dimension.Comment: 4 pages, 4 figures, uses psfig; to appear in Phys. Rev. Let

    Early and Differential Diagnosis of Dementia and Mild Cognitive Impairment Design and Cohort Baseline Characteristics of the German Dementia Competence Network

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    Background: The German Dementia Competence Network (DCN) has established procedures for standardized multicenter acquisition of clinical, biological and imaging data, for centralized data management, and for the evaluation of new treatments. Methods: A longitudinal cohort study was set up for patients with mild cognitive impairment (MCI), patients with mild dementia and control subjects. The aims were to establish the diagnostic, differential diagnostic and prognostic power of a range of clinical, laboratory and imaging methods. Furthermore, 2 clinical trials were conducted with patients suffering from MCI and mild to moderate Alzheimer's Disease (AD). These trials aimed at evaluating the efficacy and safety of the combination of galantamine and memantine versus galantamine alone. Results: Here, we report on the scope and projects of the DCN, the methods that were employed, the composition and flow within the diverse groups of patients and control persons and on the clinical and neuropsychological baseline characteristics of the group of 2,113 subjects who participated in the observational and clinical trials. Conclusion: These data have an impact on the procedures for the early and differential clinical diagnosis of dementias, the current standard treatment of AD as well as on future clinical trials in AD. Copyright (C) 2009 S. Karger AG, Base

    Longitudinal Flow of Protons from 2-8 AGeV Central Au+Au Collisions

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    Rapidity distributions of protons from central 197^{197}Au + 197^{197}Au collisions measured by the E895 Collaboration in the energy range from 2 to 8 AGeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived using a thermal model including collective longitudinal expansion are extracted from these distributions. The results show an approximately linear increase in the longitudinal flow velocity, L_{L}, as a function of the logarithm of beam energy.Comment: 5 Pages, including 3 figures, 1 tabl

    Specific bottom–up effects of arbuscular mycorrhizal fungi across a plant–herbivore–parasitoid system

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    The majority of plants are involved in symbioses with arbuscular mycorrhizal fungi (AMF), and these associations are known to have a strong influence on the performance of both plants and insect herbivores. Little is known about the impact of AMF on complex trophic chains, although such effects are conceivable. In a greenhouse study we examined the effects of two AMF species, Glomus intraradices and G. mosseae on trophic interactions between the grass Phleum pratense, the aphid Rhopalosiphum padi, and the parasitic wasp Aphidius rhopalosiphi. Inoculation with AMF in our study system generally enhanced plant biomass (+5.2%) and decreased aphid population growth (−47%), but there were no fungal species-specific effects. When plants were infested with G. intraradices, the rate of parasitism in aphids increased by 140% relative to the G. mosseae and control treatment. When plants were associated with AMF, the developmental time of the parasitoids decreased by 4.3% and weight at eclosion increased by 23.8%. There were no clear effects of AMF on the concentration of nitrogen and phosphorus in plant foliage. Our study demonstrates that the effects of AMF go beyond a simple amelioration of the plants’ nutritional status and involve rather more complex species-specific cascading effects of AMF in the food chain that have a strong impact not only on the performance of plants but also on higher trophic levels, such as herbivores and parasitoids

    Intensity modulated radiotherapy (IMRT) in the treatment of children and Adolescents - a single institution's experience and a review of the literature

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    <p>Abstract</p> <p>Background</p> <p>While IMRT is widely used in treating complex oncological cases in adults, it is not commonly used in pediatric radiation oncology for a variety of reasons. This report evaluates our 9 year experience using stereotactic-guided, inverse planned intensity-modulated radiotherapy (IMRT) in children and adolescents in the context of the current literature.</p> <p>Methods</p> <p>Between 1999 and 2008 thirty-one children and adolescents with a mean age of 14.2 years (1.5 - 20.5) were treated with IMRT in our department. This heterogeneous group of patients consisted of 20 different tumor entities, with Ewing's sarcoma being the largest (5 patients), followed by juvenile nasopharyngeal fibroma, esthesioneuroblastoma and rhabdomyosarcoma (3 patients each). In addition a review of the available literature reporting on technology, quality, toxicity, outcome and concerns of IMRT was performed.</p> <p>Results</p> <p>With IMRT individualized dose distributions and excellent sparing of organs at risk were obtained in the most challenging cases. This was achieved at the cost of an increased volume of normal tissue receiving low radiation doses. Local control was achieved in 21 patients. 5 patients died due to progressive distant metastases. No severe acute or chronic toxicity was observed.</p> <p>Conclusion</p> <p>IMRT in the treatment of children and adolescents is feasible and was applied safely within the last 9 years at our institution. Several reports in literature show the excellent possibilities of IMRT in selective sparing of organs at risk and achieving local control. In selected cases the quality of IMRT plans increases the therapeutic ratio and outweighs the risk of potentially increased rates of secondary malignancies by the augmented low dose exposure.</p

    ARTEFACTS: How do we want to deal with the future of our one and only planet?

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    The European Commission’s Science and Knowledge Service, the Joint Research Centre (JRC), decided to try working hand-in-hand with leading European science centres and museums. Behind this decision was the idea that the JRC could better support EU Institutions in engaging with the European public. The fact that European Union policies are firmly based on scientific evidence is a strong message which the JRC is uniquely able to illustrate. Such a collaboration would not only provide a platform to explain the benefits of EU policies to our daily lives but also provide an opportunity for European citizens to engage by taking a more active part in the EU policy making process for the future. A PILOT PROGRAMME To test the idea, the JRC launched an experimental programme to work with science museums: a perfect partner for three compelling reasons. Firstly, they attract a large and growing number of visitors. Leading science museums in Europe have typically 500 000 visitors per year. Furthermore, they are based in large European cities and attract local visitors as well as tourists from across Europe and beyond. The second reason for working with museums is that they have mastered the art of how to communicate key elements of sophisticated arguments across to the public and making complex topics of public interest readily accessible. That is a high-value added skill and a crucial part of the valorisation of public-funded research, never to be underestimated. Finally museums are, at present, undergoing something of a renaissance. Museums today are vibrant environments offering new techniques and technologies to both inform and entertain, and attract visitors of all demographics.JRC.H.2-Knowledge Management Methodologies, Communities and Disseminatio
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