1,274 research outputs found

    О линеаризации систем нелинейных функционально-разностных уравнений в окрестности положения равновесия

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    Встановлено умови iснування неперервної взаємно однозначної замiни змiнних, яка приводить нелiнiйну систему функцiонально-рiзницевих рiвнянь до лiнiйного вигляду.We establish conditions for the existence of a continuous one-to-one change of variables transforming a nonlinear system of functional-difference equations to that of a linear form

    Opbrengstgericht werken op de PABO: een verkenning van de wenselijkheid en mogelijkheden om opbrengstgericht werken met behulp van een leerlingvolgsysteem in het pabo curriculum op te nemen

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    Opbrengstgericht werken (OGW) kan men typeren als een aanpak waarmee gestreefd wordt naar maximale leerprestaties van alle leerlingen. Meer opbrengstgerichte scholen blijken betere prestaties te boeken dan scholen die deze aanpak van OGW niet of nog minder in de praktijk brengen. In verband daarmee is het wenselijk dat aanstaande leraren basisonderwijs tijdens hun initiële opleiding ook gedegen worden voorbereid op zich de veranderende beroepspraktijk en zich de theorie en praktijk van OGW eigen te maken. OGW blijkt op veel pabo’s nog geen geïntegreerd onderdeel van het curriculum uit te make

    Технология и свойства пористого гранулированного стеклокристаллического материала из высокодисперсного кремнеземистого сырья

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    This paper reports on the regional screening, selection and geological characterisation of a potential on-shore CO2 storage site (saline aquifer) in north-eastern Germany. The main objective of this study was to identify and investigate a candidate storage site, capable to accommodate the total amount of approximately 400 million tons of CO2. Such a volume is produced by a modern, lignite-fired power plant within its operation lifetime of approximately 40 years. Within north-eastern Germany, several saline aquifers of Triassic, Jurassic and Cretaceous age have been evaluated with respect to their regional occurrence, storage potential and basic reservoir properties. Subsequent to a ranking, considering different criteria, the anticlinal structure Schweinrich holding suitable saline aquifers of the uppermost Triassic and lowest Jurassic has been selected from a number of identified candidate sites. According to results of the geological site characterisation, including structural geological investigations and 3D reservoir modelling, the structure Schweinrich seems to be a suitable site for industrial large scale CO2 storage. Further data acquisition (new wells and 3D seismics) and research (more detailed and comprehensive modelling) is needed in order to prove the structural integrity of the storage site and assure long-term safety. © 2007 Springer-Verlag

    Aanvullend onderzoek mineralenconcentraten 2009-2010 op bouwland en grasland : samenvatting van de resultaten uit de veldproeven en bepaling van de stikstofwerking

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    Bij mestscheiding volgens het proces van ultrafiltratie en omgekeerde osmose ontstaat een mineralenconcentraat (MC), dat voornamelijk stikstof en kali bevat en wordt beoogd als kunstmestvervanger. Voor (wettelijke) erkenning als kunstmestvervanger is het belangrijk dat de stikstofwerking van het MC hoog is. In 2009 is de Rijksoverheid (de ministeries van LNV thans EL&I en VROM thans I&M) samen met het landbouwbedrijfsleven (LTO en NAV) een pilot gestart waarbinnen onder andere onderzoek plaatsvindt naar de landbouwkundige en milieukundige effecten van het gebruik van mineralenconcentraten. Daartoe zijn ondermeer verdiepende veldproeven uitgevoerd in 2009 en 2010 met aardappelen en grasland. Als aanvulling op deze pilot wordt van 2009 t/m 2011 een project uitgevoerd waarin een goede toedieningstechniek met praktijkmachines centraal staat. Dit project omvat veldproeven en demonstraties in diverse akkerbouwgewassen, in snijmaïs en op grasland. Dit verslag vat de resultaten van deze aanvullende veldproeven in 2009 en 2010 samen en gaat ook in op de stikstofwerking van het MC in de diverse proeven bij verschillende toedieningstechnieken. De proeven zijn in 2009 en 2010 uitgevoerd met zetmeelaardappelen op dalgrond, wintertarwe op zware zeeklei (Oldambt) en zomergerst op dalgrond (2009) en NO zandgrond (2010). Verder zijn in 2010 proeven uitgevoerd op ZO zandgrond met consumptieaardappelen, snijmaïs en op grasland en op ZW zeeklei met consumptieaardappelen

    Reduced mortality and subsequent fracture risk associated with oral bisphosphonate recommendation in a fracture liaison service setting: A prospective cohort study

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    Objective: Osteoporotic fragility fractures, that are common in men and women, signal increased risk of future fractures and of premature mortality. Less than one-third of postmenopausal women and fewer men are prescribed active treatments to reduce fracture risk. Therefore, in this study the association of oral bisphosphonate recommendation with subsequent fracture and mortality over eight years in a fracture liaison service setting was analysed. Materials and methods: In this prospective cohort study, 5011 men and women aged \u3e50 years, who sustained a clinical fracture, accepted the invitation to attend the fracture liaison service of the West Glasgow health service between 1999 and 2007. These patients were fully assessed and all were recommended calcium and vitamin D. Based on pre-defined fracture risk criteria, 2534 (50.7%) patients were additionally also recommended oral bisphosphonates. Mortality and subsequent fracture risk were the pre-defined outcomes analysed using Cox proportional hazard models. Results: Those recommended bisphosphonates were more often female (82.9 vs. 72.4%), were older (73.4 vs. 64.4 years), had lower bone mineral density T-score (-3.1 vs. -1.5) and more had sustained hip fractures (21.7 vs. 6.2%; p \u3c 0.001). After adjustments, patients recommended bisphosphonates had lower subsequent fracture risk (Hazard Ratio (HR): 0.60; 95% confidence interval (CI): 0.49±0.73) and lower mortality risk (HR: 0.79, 95%CI: 0.64±0.97). Conclusion: Of the patients, who are fully assessed after a fracture at the fracture liaison service, those with higher fracture risk and a recommendation for bisphosphonates had worse baseline characteristics. However, after adjusting for these differences, those recommended bisphosphonate treatment had a substantially lower risk for subsequent fragility fracture and lower risk for mortality. These community-based data indicate the adverse public health outcomes and mortality impacts of the current low treatment levels post fracture could be improved by bisphosphonate recommendation for both subsequent fracture and mortality

    Does experience influence the forces exerted on maxillary incisors during laryngoscopy? A manikin study using the Macintosh laryngoscope

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    The influence of the level of experience of the laryngoscopist on the duration of laryngoscopy, the forces exerted on the tongue and on the maxillary incisors during laryngoscopy, were investigated. Five groups (anaesthetists, residents in anaesthesia, nurse anaesthetists, surgeons and medical students), each consisting of 15 individuals, participated in the study. An intubation manikin was used with a laryngoscope modified so that the forces applied during laryngoscopy could be measured. The mean duration of laryngoscopy in these groups was 23.4 sec, 17.6 sec, 27.1 sec, 26.8 sec and 42.7 sec, respectively. The maximally applied forces on the tongue were 71.7 N, 60.5 N, 65.9 N, 74.2 N and 69.7 N, respectively. The maximally applied forces on the maxillary incisors were 49.9 N, 36.3 N, 41.1 N, 58.3 N and 53.9 N, respectively. These results indicate the level of experience has a significant influence on the duration of laryngoscopy but seems to have little influence on the forces applied to the tongue and the maxillary incisors

    Teeltvervroeging bij consumptieaardappel en snijmaïs op zand ten behoeve van vanggewassen

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    Een na-oogstmaatregel om het verlies van stikstof (N) naar het grond- en oppervlaktewater te beperken, is het telen van een onbemeste groenbemester als stikstofvanggewas na de hoofdteelt. Belangrijke factoren die de effectiviteit van een vanggewas bepalen, zijn een voldoende gewasontwikkeling en opname van de reststikstof in de nazomer/herfst en een goede benutting van de door het vanggewas opgenomen stikstof door het volggewas. De mate van ontwikkeling en stikstofopname van het vanggewas hangt onder meer af van het zaaitijdstip. Op circa 18% van het aardappelareaal op zuidelijk zand (zo‟n 2.200 ha, incl. pootgoedteelt) worden op dit moment de aardappelen vroeg genoeg gerooid (vóór 1 september) om een geslaagd vanggewas te kunnen tele

    Measurement of exclusive production of scalar χc0\chi_{c0} meson in proton-(anti)proton collisions via χc0π+π\chi_{c0} \to \pi^{+}\pi^{-} decay

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    We consider a measurement of exclusive production of scalar χc(0++)\chi_{c}(0^{++}) meson in the proton-proton collisions at LHC and RHIC and in the proton-antiproton collisions at the Tevatron via χc0π+π\chi_{c0} \to \pi^{+}\pi^{-} decay. The corresponding amplitude for exclusive double-diffractive χc0\chi_{c0} meson production was obtained within the ktk_{t}-factorization approach including virtualities of active gluons and the corresponding cross section is calculated with unintegrated gluon distribution functions (UGDFs) known from the literature. The four-body ppppπ+πp p \to p p \pi^+ \pi^- reaction constitutes an irreducible background to the exclusive χc0\chi_{c0} meson production. We calculate several differential distributions for pp(pˉ)pp(pˉ)χc0pp(\bar{p}) \to pp(\bar{p})\chi_{c0} process including absorptive corrections. The influence of kinematical cuts on the signal-to-background ratio is investigated. Corresponding experimental consequences are discussed.Comment: 16 pages, 10 figures, 2 table

    Decadal-centennial scale monsoon variations in the Arabian Sea during the Early Holocene

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    An essential prerequisite for the prediction of future climate change due to anthropogenic input is an understanding of the natural processes that control Earth's climate on timescales comparable to human-lifespan. The Early Holocene period was chosen to study the natural climate variability in a warm interval when solar insolation was at its maximum. The monsoonal system of the Tropics is highly sensitive to seasonal variations in solar insolation, and consequently marine sediments from the region are a potential monitor of past climate change. Here we show that during the Early Holocene period rapid

    Forces acting on the maxillary incisor teeth during laryngoscopy using the Macintosh laryngoscope

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    We determined the forces on the maxillary incisors during routine laryngoscopy in 65 adult patients. The forces were measured by a strain gauge based sensor positioned between the handle and the blade of the laryngoscope. The mean maximal force acting on the maxillary incisors was 49 N. In patients without maxillary incisors, the force acting on the gums was significantly lower at 21N (p < 0.001). These results suggest that, despite traditional advice to the contrary, a levering movement of the laryngoscope, using the maxillary incisors (or gums) as a fulcrum, is common practice. Biomechanical analysis revealed that, although levering is not the preferred movement, it is an efficient way of bringing the glottis into view. These results may have implications for future laryngoscope design
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