18 research outputs found
A1-L12 interfacial free energies from data on coarsening in five binary Ni alloys, informed by thermodynamic phase diagram assessments
Release of compressive intrinsic stress in ultraclean thin nickel films as a result of adsorption of gases
No abstract
Reaction diffusion and Kirkendall-effect in the nickel-aluminum system
Chem. diffusion coeffs. and heats of activation for diffusion in the Ni2Al (g), NiAl (d), and Ni3Al (e) intermetallic phases and the solid soln. of Al in Ni (z phase), were calcd. from layer growth expts. No finite diffusion coeff. for the NiAl3 (b) intermetallic phase could be calcd. The values of the diffusion coeffs. are dependent both on the method of calcn. and the type of diffusion couple. The heat of activation for diffusion in the g phase was 47 kcal./mole in the range 428-610 Deg. Heats of activation of 41, 12, and 48 kcal./mole were found for diffusion in the d, e, and z phases, resp., in the range 655-1000 Deg. Expts. with markers in the diffusion zone demonstrate a very pronounced Kirkendall effect. It appears that only Al atoms take an active part in the diffusion process during the formation of the b and g phases at .apprx.600 Deg. During the formation of the d, e, and z phases at higher temps. only Ni atoms are moving. It is suggested that the great stability of the intermetallic compds. in the Ni-Al system governs the Kirkendall effect. 20 references. [on SciFinder (R)
Onzekerheidsanalyse van de NOx emissie van Nederlandse personenauto's in 1998
In decision-making processes on emission reduction, not only are emission data needed but also information on the uncertainty of these data. Here, structured expert elicitation was used an uncertainty analysis on NOx emissions from Dutch passenger cars in 1998. Experts from several Dutch research institutes were elicited on individual car performance (emission factors) and volumetric (kilometres driven) variables could be obtained with the expert elicitation method. Total population uncertainty was calculated by propagation and aggregation of individual car uncertainty in a Monte Carlo simulation. The calculation process was explicitly geared to variables showing inherent variability (aleatory uncertainty) and variables that are uncertain because of a lack of knowledge (epistemic uncertainty). The smallest 95% uncertainty interval for total population NOx emission was obtained for the TNO-CBS (Statistics Netherlands) expert (-12% to +15%), while the largest interval was obtained for the RIVM expert (-35% to +51%). The combination of experts (called decision-makers [DM]) showed intervals of -30% to +41% (DM before propagation) and -46% to +81% (DM after aggregation). The use of structured expert elicitation was very time consuming, and there is still a lot of discussion on combining expert data. Therefore, the need for structured expert elicitation should be firmly substantiated and focused on sensitive and controversial variables.Bij besluitvorming over maatregelen op het gebied van emissie-reductie zijn niet alleen gegevens over emissies nodig maar ook over de onzekerheid daarvan. Dit rapport beschrijft een studie naar het gebruik van gestructureerde expertbevraging bij onzekerheidsanalyse van de NOx-emissies uit personenauto's. Experts van verschillende Nederlandse onderzoeksinstituten zijn bevraagd over prestatiegegevens (emissie-factoren) en volumegegevens (kilometrages). De totale populatie onzekerheid is berekend door het opschalen van de onzekerheid van individuele auto's door Monte Carlo simulaties. In de berekening is expliciet onderscheid gemaakt tussen variabelen die inherent variabel zijn (aleatorische onzekerheid) en variabelen die onzeker zijn vanwege een gebrek aan kennis (epistemische onzekerheid). Het kleinste 95% betrouwbaarheidsinterval werd verkregen voor de TNO-CBS expert (-12% tot +15%), en het grootste interval voor de RIVM expert (-35% tot +51%). De combinatie van experts (decision-makers [DM] genoemd in deze methode) kreeg intervallen van -30% tot +41% (DM voor propagatie) en van -46% tot +81% (DM na aggregatie). Het gebruik van expert bevraging bleek arbeidsintensief en er is veel discussie over het wel of niet combineren van expert antwoorden. Het gebruik van deze methode moet daarom goed onderbouwd worden, en moet zich richten op de meest gevoelige en controversiele parameters
Onzekerheidsanalyse van de NOx emissie van Nederlandse personenauto's in 1998
Bij besluitvorming over maatregelen op het gebied van emissie-reductie zijn niet alleen gegevens over emissies nodig maar ook over de onzekerheid daarvan. Dit rapport beschrijft een studie naar het gebruik van gestructureerde expertbevraging bij onzekerheidsanalyse van de NOx-emissies uit personenauto's. Experts van verschillende Nederlandse onderzoeksinstituten zijn bevraagd over prestatiegegevens (emissie-factoren) en volumegegevens (kilometrages). De totale populatie onzekerheid is berekend door het opschalen van de onzekerheid van individuele auto's door Monte Carlo simulaties. In de berekening is expliciet onderscheid gemaakt tussen variabelen die inherent variabel zijn (aleatorische onzekerheid) en variabelen die onzeker zijn vanwege een gebrek aan kennis (epistemische onzekerheid). Het kleinste 95% betrouwbaarheidsinterval werd verkregen voor de TNO-CBS expert (-12% tot +15%), en het grootste interval voor de RIVM expert (-35% tot +51%). De combinatie van experts (decision-makers [DM] genoemd in deze methode) kreeg intervallen van -30% tot +41% (DM voor propagatie) en van -46% tot +81% (DM na aggregatie). Het gebruik van expert bevraging bleek arbeidsintensief en er is veel discussie over het wel of niet combineren van expert antwoorden. Het gebruik van deze methode moet daarom goed onderbouwd worden, en moet zich richten op de meest gevoelige en controversiele parameters.In decision-making processes on emission reduction, not only are emission data needed but also information on the uncertainty of these data. Here, structured expert elicitation was used an uncertainty analysis on NOx emissions from Dutch passenger cars in 1998. Experts from several Dutch research institutes were elicited on individual car performance (emission factors) and volumetric (kilometres driven) variables could be obtained with the expert elicitation method. Total population uncertainty was calculated by propagation and aggregation of individual car uncertainty in a Monte Carlo simulation. The calculation process was explicitly geared to variables showing inherent variability (aleatory uncertainty) and variables that are uncertain because of a lack of knowledge (epistemic uncertainty). The smallest 95% uncertainty interval for total population NOx emission was obtained for the TNO-CBS (Statistics Netherlands) expert (-12% to +15%), while the largest interval was obtained for the RIVM expert (-35% to +51%). The combination of experts (called decision-makers [DM]) showed intervals of -30% to +41% (DM before propagation) and -46% to +81% (DM after aggregation). The use of structured expert elicitation was very time consuming, and there is still a lot of discussion on combining expert data. Therefore, the need for structured expert elicitation should be firmly substantiated and focused on sensitive and controversial variables.RIV
Update of the national emission projections for SO2, NOx, NH3, NMVOC and PM10 up to 2010
Dit rapport bevat een actualisatie uitgevoerd in 2003 ten behoeve van de Uitvoeringsnota Verzuring en grootschalige luchtverontreiniging 2003Op 19 december 2003 heeft het kabinet de Uitvoeringsnota verzuring en grootschalige luchtverontreiniging 2003 'Erop of eronder' gepubliceerd. Doelstelling van de Uitvoeringsnotitie is de realisatie van de nationale emissieplafonds voor SO2, NOx, NH3 en NMVOS uiterlijk in 2010. Ten behoeve van deze Uitvoeringsnotitie heeft het Milieu- en Natuurplanbureau van het RIVM de prognose voor de emissies in 2010 aangepast aan nieuwe inzichten en trends. De geactualiseerde emissieprognoses voor SO2, NOx, NH3 en NMVOS (en fijn stof) worden in dit rapport gepresenteerd. De ramingen houden rekening met het door de tweede kamer geaccordeerde beleid tot Juli 2003. De effecten van het nieuw aangekondigde in de Uitvoeringsnota 'Erop of Eronder' zijn niet verwerkt in de ramingen met uitzondering van NOx-emissiehandel. De aangepaste raming toont aan dat bij uitvoering van het geaccordeerde beleid de emissieplafonds voor SO2, NOx en NMVOS waarschijnlijk niet worden gehaald. Aanvullende maatregelen zijn nodig. Voor NH3 lijkt het plafond haalbaar, hoewel er een kans aanwezig is dat het plafond toch overschreden wordt. Na doorvoering van het afgesproken beleid worden de plafonds voor SO2, NOx en NMVOS met resp. circa 15, 28 en 15 miljoen kg overschreden. Het emissieplafond voor NH3 wordt naar verwachting met circa 7 miljoen kg onderschreden. In 2005 wordt een nieuwe referentieraming opgesteld door ECN en RIVM voor de periode tot 2020. Op dat moment worden ook de emissieprognoses voor 2010 bijgesteld.In december 2003 the Dutch Government has set down a national programme for the reduction of sulphur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (NMVOC) and ammonia (NH3) in an implementation memorandum called 'Erop or Eronder'. For this memorandum, the Netherlands Environmental Assessment Agency (RIVM/MNP) took on the task of updating the emission projections according to the latest insights into emission sources, policies and trends up to 2010. The updated emission projections for SO2, NOX, NH3, NMVOC (and also PM10) will be presented in this report. The projection includes current policy decisions up to July 2003. Effects of new measures announced in the implementation memorandum 'Erop of Eronder' have not been considered in the projections with the exception of the Dutch NOx-emission trading system. Projections show that given current policies, the emission ceilings for SO2, NOX and NMVOC will probably not be met in 2010. Additional measures are needed. The emission ceiling for NH3 seems attainable, although there is still a chance that the ceiling will be exceeded. Results show that the ceiling for SO2, NOX and NMVOC will be exceeded by approximately 15, 28 and 15 million kg, respectively. Projected emissions for NH3 are ascertained at about 7 million kg below the emission ceiling. In 2005 the Netherlands Environmental Assessment Agency (RIVM/MNP) will publish new projections up to the year 2020 in cooperation with the Netherlands Energy Research Foundation (ECN). Emission projections for the year 2010 will then also be updated.VRO
Variation in referrals to secondary obstetrician-led care among primary midwifery care practices in the Netherlands: a nationwide cohort study
Contains fulltext :
154413.pdf (publisher's version ) (Open Access)BACKGROUND: The primary aim of this study was to describe the variation in intrapartum referral rates in midwifery practices in the Netherlands. Secondly, we wanted to explore the association between the practice referral rate and a woman's chance of an instrumental birth (caesarean section or vaginal instrumental birth). METHODS: We performed an observational study, using the Dutch national perinatal database. Low risk births in all primary care midwifery practices over the period 2008-2010 were selected. Intrapartum referral rates were calculated. The referral rate among nulliparous women was used to divide the practices in three tertile groups. In a multilevel logistic regression analysis the association between the referral rate and the chance of an instrumental birth was examined. RESULTS: The intrapartum referral rate varied from 9.7 to 63.7 percent (mean 37.8; SD 7.0), and for nulliparous women from 13.8 to 78.1 percent (mean 56.8; SD 8.4). The variation occurred predominantly in non-urgent referrals in the first stage of labour. In the practices in the lowest tertile group more nulliparous women had a spontaneous vaginal birth compared to the middle and highest tertile group (T1: 77.3%, T2:73.5%, T3: 72.0%). For multiparous women the spontaneous vaginal birth rate was 97%. Compared to the lowest tertile group the odds ratios for nulliparous women for an instrumental birth were 1.22 (CI 1.16-1.31) and 1.33 (CI 1.25-1.41) in the middle and high tertile groups. This association was no longer significant after controlling for obstetric interventions (pain relief or augmentation). CONCLUSIONS: The wide variation between referral rates may not be explained by medical factors or client characteristics alone. A high intrapartum referral rate in a midwifery practice is associated with an increased chance of an instrumental birth for nulliparous women, which is mediated by the increased use of obstetric interventions. Midwives should critically evaluate their referral behaviour. A high referral rate may indicate that more interventions are applied than necessary. This may lead to a lower chance of a spontaneous vaginal birth and a higher risk on a PPH. However, a low referral rate should not be achieved at the cost of perinatal safety